# Buddy's Breadboard and Circuit Design Notes - You May Learn Something



## BuddytheReow

Hey all,

If you are frequent travelers of this forum you may have noticed that I've been asking a lot of breadboard questions recently. What kind of breadboard is best? How do I mount pots to them? Jumper cables? I finally bit the bullet and did a Tayda run. As of today it is still in transit. However, I realized I was trying to get rid of an Arduino starter recently (BTW still up for grabs so please message me; it is barely used) and it had a breadboard and some jumper wires in it so I decided to take it out and start!

A little background on my building/electronics...I started building toward the end of 2019. My wife just finished reading Adam Savage's (the Mythbuster's guy) autobiography and told me I would probably like it too since we were both fans of the show back in its heyday. At one point in the book there is a picture of him in his apartment kneeled on the floor over a telecaster with all it parts strewn all over the floor. He talked about just wanting to learn how things work by tinkering. Now, I've been playing guitar for almost 20 years (took almost 5 years off due to grad school and CPA exams - I am an accountant and yes, I breathe Excel ). I thought to myself after seeing that picture: "Hey, this guy has no clue about how a guitar works, but I do from a high level. Maybe I should give it a try and build a guitar." So I bought a kit which included sanding, finishing, and wiring the pickups/pots. At first I was nervous about the soldering part since I've never done something like that before. Thank you YouTube and my dad for helping out on that! Soldering was pretty simple, and THAT's what sparked the "creator" in me. From there, I decided to build a tubescreamer kit from General Guitar Gadgets. From there I stumbled upon this site and also discovered Tayda. I told myself and my wife "I can save A LOT of money building these myself!"  4 pedals later I decided to go down the stripboard path; again, I thought I was "saving" even more money vs buying PCBs but realized quickly the tradeoff of tidiness. Stripboard builds then required me to build a test box to essentially bypass the offboard wiring step to see if a build works and am super grateful for it. IMO, the more complex the circuit the more likely a PedalPCB purchase is necessary due to board size and again, tidiness.

So....maybe 3 dozen stripboard builds and 4 pedals later, I started getting tired of building clones. Don't get me wrong, I learned a TON about circuits mostly due to troubleshooting and learning how to do that process myself mostly due to you guys and the rest of the internet. Sure, clones are nice to have, but I wanted to take the "create" process a step further and build a circuit from scratch. My only formal education was high school physics where we spent a month or two on electricity. That was 15 years ago (showing my age here) and remember virtually nothing other than ohm's law and the right hand rule (electomagnetism). Building from scratch is a tall order if you have no idea how things work.

Getting the bug to create forced me to learn a lot of the basics in circuit design and I'm still learning here. The learning process started with the basics (this is what a resistor/capacitor/diode/transistor/etc. does) and am now learning some basic pieces (basic booster, diode clipping, tone stacks, etc.). I will be sharing my builds and any notes here for anyone who wishes to go along the journey with me. First build coming soon...


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## BuddytheReow

The first thing I took to my breadboard was an LPB-1. Made one mistake and the signal did not get louder, but it did conduct signal. The issue was that I attached the output cap to the base rather than the collector. Simple fix and lo and behold, it worked!
Decided not to take pics of this for one reason, but justified it into 2: the circuit is not that exciting and I didn’t think of taking pictures until I took all the components out!

Another thing I noticed is that if keep breadboarding with the same components, particularly resistors, the leads will snap off. Not sure if all resistors are like this or if that’s the way Tayda makes their products. So, I decided to bite the bullet and drop $10 on Amazon for a basic resistor kit specifically for breadboarding. This way I can still build on the side with my main components and not have to worry about breaking the leads off of them.

I will share my first “real” build here shortly…


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## BuddytheReow

OK. I've been spending the past few days on Jack Orman's site (muzique.com). Big shout out to one of the original gurus. Anyways I stumbled upon this as a starting point. It is taken from a Big Muff. Taking the diodes and C3 out, it is a simple booster. The issue I have is that my pickups are a bit too hot for this circuit since they are humbuckers, although my LP has a coil splitter. This makes the transistor gate slightly and sounds a bit like a fuzz. Correction, I believe the term here is clipping. One note here is that I used a 180 ohm resistor instead of a 150 for r4. Doesn’t that affect the gain? Need to look at my notes.




From here I experimented with the diode section and used the standard 1n4148. I didn't like the "soft clipping" here since the guitar is clipping it slightly already. So, I moved the diodes after C2 and shunt to ground to get a hard clipping sound and removed C3 entirely. Muuuuuch better!

Continuing to dig around the site I decided to add a standard BMP tone stack after the clipping. The internet says this is a passive tone control and now I know why...this sucks out a decent amount of volume. From the tone stack goes the 100k volume pot to ground.

Pics to follow


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## BuddytheReow

Since these are mostly Big Muff circuit blocks, I have decided to call this the “Egg McMuffin.”

Edit: Soundwise it is decent, but I know I can start playing with the EQ filters a bit to get something better. The tonestack made a HUGE difference in the tones generated. Perhaps I should tack on a recovery boost stage afterwards instead of almost unity? Maybe another day..


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## BuddytheReow

I’m still going through basics here, but now I’m trying to mix and match circuit blocks. This is an Electra distortion with 4148 diodes into a BMP tone stack followed by a BMP recovery stage. Curious, couldn’t I just put another Electra distortion after the tone stack and remove the diodes? I mean, that would make it a booster, but still…

soundwise it’s a little boring but the tone stack helps. I can definitely tell from the sound that I’m using transistors due to hot pickups. I’m going to see if I can take a stab at an opamp circuit.

I call it the “Electric Muff”.


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## BuddytheReow

This is the first "building block" I learned to me makes the most difference to the sound of nearly any circuit. It is a Big Muff tone stack and is considered "passive", meaning it doesn't take any power to use and there are a few components to ground. The downside to this simple circuit is that it drops the output volume enough to be annoying. At least in the BMP circuit this is done after all the other clipping stages before the boost/recovery section. If anyone is interested in learning more about this check out Jack Orman's site here http://www.muzique.com/lab/atone.htm.


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## Coda

BuddytheReow said:


> This is the first "building block" I learned to me makes the most difference to the sound of nearly any circuit. It is a Big Muff tone stack and is considered "passive", meaning it doesn't take any power to use and there are a few components to ground. The downside to this simple circuit is that it drops the output volume enough to be annoying. At least in the BMP circuit this is done after all the other clipping stages before the boost/recovery section. If anyone is interested in learning more about this check out Jack Orman's site here http://www.muzique.com/lab/atone.htm.
> 
> View attachment 14263


This is helpful. I breadboarded a Axis Fuzz this morning, and it was so bright that it just about blew my ears off. I may tack this on to the end of the circuit and see what happens…


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## BuddytheReow

Coda said:


> This is helpful. I breadboarded a Axis Fuzz this morning, and it was so bright that it just about blew my ears off. I may tack this on to the end of the circuit and see what happens…


I would be careful here. If you find that it's too bright to begin with then half of the tone stack pot would make it worse. I would use the top half of this circuit here but remove R1. This is taken from that same article I shared.


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## Feral Feline

CRAP!

I typed a lot in a reply to the topic and was switching between windows to grab some URLs for you, then accidentally wiped out everything I'd written trying to click back on this thread and closing the window instead. GRRRR 😾


Trying to recap from memory (at least it'll be more brief this time round)...

Enjoying living vicariously through your efforts here, thanks for posting.

Most EQ is "lossy", 'cause most EQ is just dumping frequencies to ground — hence the need for a recovery stage (or mega-boosted before the EQ). By all means, try the Electra sans diodes as a recovery stage. Try a SHO, too, then try an MXR Micro-amp as your op-amp recovery stage...

Check out Brian Wampler's "How to Design Circuits" or "How to Design Pedals" or whatever the title actually is — there're PDFs of it floating on the Interwebs or you can buy it on glut-online-seller Ahmalgazone.

Also check out ESP for "Designing With Opamps" Parts 1 & 2  by Rod Elliott.



@Coda Check out AMZ's take(s) on Mark Hammer's Stupidly Wonderful Tone Control (SWTC). Just the thing for axing the edge off your Axis.

Sorry guys, not going to give you the URLs, lest I inadvertently delete my post yet again — I'm sure you can seek out the suggestions if you like.


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## Coda

Feral Feline said:


> CRAP!
> 
> I typed a lot in a reply to the topic and was switching between windows to grab some URLs for you, then accidentally wiped out everything I'd written trying to click back on this thread and closing the window instead. GRRRR 😾
> 
> 
> Trying to recap from memory (at least it'll be more brief this time round)...
> 
> Enjoying living vicariously through your efforts here, thanks for posting.
> 
> Most EQ is "lossy", 'cause most EQ is just dumping frequencies to ground — hence the need for a recovery stage (or mega-boosted before the EQ). By all means, try the Electra sans diodes as a recovery stage. Try a SHO, too, then try an MXR Micro-amp as your op-amp recovery stage...
> 
> Check out Brian Wampler's "How to Design Circuits" or "How to Design Pedals" or whatever the title actually is — there're PDFs of it floating on the Interwebs or you can buy it on glut-online-seller Ahmalgazone.
> 
> Also check out ESP for "Designing With Opamps" Parts 1 & 2  by Rod Elliott.
> 
> 
> 
> @Coda Check out AMZ's take(s) on Mark Hammer's Stupidly Wonderful Tone Control (SWTC). Just the thing for axing the edge off your Axis.
> 
> Sorry guys, not going to give you the URLs, lest I inadvertently delete my post yet again — I'm sure you can seek out the suggestions if you like.


Thanks for the tip. I looked into, and added it to my breadboard. I can definitely hear a difference in tone, but the tone is still pretty piercing. I think that's the nature of the pedal. It was based on the Fuzz-Rite, and that pedal also seems to have too much treble. I say "seems" because I only hear it live in the room. Recorded you'd never know. Meanwhile, my ears are hear bleeding...


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## BuddytheReow

@Mcknib pointed me toward Beavis Audio. I was drawn to the breadboard projects since that's what im into right now and loving the learning process. One of the things I stumbled upon comes from here. http://beavisaudio.com/beavisboard/projects/bbp_DiodeMods.pdf. I'm going to be doing some projects from here since there are a dozen or so relatively easy ones. I won't match the breadboard layout because I kind of want to figure those things out on my own.

Personally, I don't agree with the asymmetric clipping ones since one lead of the single diode isn't connected to anything. The simple fix is to extend the lead to match the double diode connection. Since in my head the layout doesn't make sense I didn't try it as written.

I think this is a great resource right here for anyone who's interesting in designing or modding a distortion/OD/fuzz pedal. In my opinion the 2 warp controls are very subtle. Either that or the pots I used were the wrong value. I think I used 100k.

I'm a distortion junkie, so naturally I tested with LEDs. Looking at any voltage drop chart, Red ones clip the most and white clips the least. To remember I was reminded of how kids learn the colors of the rainbow: ROY. G. BIV and in that order from most to least clippping.


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## BuddytheReow

For anyone who's been reading this thread or cares, anything that I post with either a screenshot or link comes from someone else who did all the work and I do not take any credit for their time an effort. I am merely collecting and passing along any information I find that may be useful to myself or anyone else who wants to join me in the learning process of circuits.

Sorry. Part of me felt like I had to put a disclaimer in at some point


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## BuddytheReow

Before I went away over the weekend I took some time and looked through the Beavis Audio projects for a good modding project. I think modding an existing circuit would allow me to understand what part does what in any given circuit. As mentioned I am a distortion junkie so I wanted to start with a classic: MRX Distortion +.

As I'm writing this I realized this is something that Chuck does on a frequent basis, but I wanted to share my experience and also look at his posts too to cross reference.

I have built this circuit on stripboard before and was pretty pleased with the overall sound given the amount of parts it takes. Now that I have a breadboard its time to "tinker" as my wife likes to say.

Since this is a basic, hard clipping circuit I decided to tweak the clipping using some of the mods listed above. Too the diodes out first to test the raw opamp sound and it was pretty clipped to begin with. Swapped the 1n914 with red LEDs and loved the "harsher" sound it gave. My first mod!! I then tried the "warp" mod and found it too subtle for my taste. Asymmetrical LEDs made the sound a bit "warmer" but still the desired harshness, so I kept it in.

I looked at the power supply and saw it was a very basic voltage divider with a 1uf DC filter so no changes would be made there. *Does anyone know the purpose of R3 (1m)?* Something to do with impedance maybe? Still having trouble with this in relation to circuit design.

I then took a look at the negative feedback loop. Taking the 10p cap out made the sound too harsh, but the larger the values I subbed in there removed more overall distortion. Decided to keep the cap at 10p. R6 I found out controls the overall gain of the opamp, so I put in a 2.2m and kept it. C4 and R5 to me appear to be a tone filter and didn't get around to playing with it since I am not that educated in that yet.

In/out caps (c2 and c6). C2 provides DC and tone filtering? The larger the value of c2 i used the more bass came through. I kept it at 1u since i think it should have more "chunk". C6 looking at this after the fact seems to be a low pass filer, but could be wrong. Anyway, the larger values I put in there the less overall distortion I heard. Taking the cap out entirely didn't change much of the sound.

The original IC is an LM 741, but I went with what Beavis Audio has in the project. I tried swapping that out for a tl072 and noticed no difference in sound to my ears.

*Any ideas or other good mods to do for this?* Was thinking a tone control, but since I only know BMP and given how bright the sound already is and the volume drop it produces I decided to nix it. Maybe when I learn active tone stacks I can circle back to this project.

Edit: pics added


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## fig

I might be mistaken here, but R1 is the pull-down resistor to lower input impedance, and the voltage divider is R2/R3.


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## BuddytheReow

I thought the pull down resistor is right after the signal input and goes to ground. There doesn't appear to be one here


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## fig

Yeah, you're right! Could it be an attenuation setup for when it dovetails into the audio and opamp?

One way to know for certain what effect it has is to audio probe / or grab a waveform at pin 3 of the opmap.


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## BuddytheReow

For anyone who wants to learn with me...

When I started this thread I had the goal of being able to design my own circuit. As a distortion junkie, I really wanted to build an op amp based circuit with tone controls, diode selectors, boosters, etc and move on from there to different effects. Here's my first breakthrough after doing a lot of reading and breadboarding. It is a basic, non-inverted op amp gain circuit and the design is seen in things like the Dist +, Rat, Guvnor, etc.

I found this on General Guitar Gadgets and will post the link here. This goes through a lot of the parts to build a basic clipping circuit with tone control. I stripped it down to, what I think, are the bare bones. The power supply stage is removed here, but it is a simple voltage divider along with a 4.7uf electrolytic cap to filter and ripples and highlighted which voltage goes where. Also, the IC needs to be grounded. A 4558 IC is at pin 4 for ground and pin 8 for 9v. I will explain what each part does and directly comes from the circuit analysis from the link. My comments are in green.




R1 acts as a click-preventing resistor. It cuts out all clicks and other unpleasant sounds from the signal. This part is needed or else the circuit won't work.
C2 also filters DC voltage from getting into your guitar. R1 and C2 also form a high-pass filter. Cuts frequencies below 16hz. 
R2 and C1 form a low-pass filter, which rolls off out the radio frequencies. About 16kHz. Between these two filters only guitar signal can go through to get amplified.
Input gets biased through R3. Still scratching my head why this is needed but I tried removing it here and the circuit didn't work. So, it stays. Brian Wampler likes to use 470k here for most of his circuits.
R4 and R5 set the gain. Since R4 is a potentiometer, the gain can vary from 1 to 101. I think the calculation is (R4 + R5)/R4. Higher pot values mean more gain. Lugs 2 and 3 are connected.
R5 and C4 form another low pass filter. I didn't think this was necessary since it is merely a filter, but the circuit wouldn't work as it should. This combo determines the frequency that gets passed on to be amplified as per Brian Wampler (went through his "advanced" book last night) and was my _Eureka! moment._
R4 and C3 form the high pass filter, and since R4 is a pot, the roll-off frequency will vary as you turn the pot.
C5 prevents DC voltage from getting into your amp. Since C5 and the volume control R7 form a high pass filter, the value of C5 has to be high enough to prevent the roll-off frequency to interfering with your signal (10uF should be enough). I think I put a 100n cap here since that seems to be the standard in a lot of diy circuits. Sound was a bit treble-y, but I like that where you can hear the pick attack.
R7 is the volume control.


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## BuddytheReow

In writing my last post and trying to find frequencies of guitar signal I stumbled upon this. Seemed very useful and comes from here.

*Key Audible Electric Guitar Range* = c80 Hz - c7,000 Hz

(These are the frequencies most people can hear, most everything else is texture and atmosphere.)


*20 - 80 Hz* : Deep Bass, can add muffle and muddiness, can also thicken sound to a degree. 20 Hz usually lower kick-drum frequency, low-end bass is around 60 - 100 hz. For electric guitar you would typically cut anything below 100Hz
*80 - 120 Hz* : typical low-end guitar frequencies - cut below 100hz to give space to low-end bass and percussion
*100 - 300 Hz* : used to add fullness of sound / thickness & body to guitar, just a little though as too much here muffles and can create flubbiness / warble
*300 - 1,000 Hz* : Liveliness / attack - adds some electrical sizzle
*1,000 - 2,000 Hz* : ’Honk’ / nasally guitar sounds - boost or cut
*2,000 - 2,500 Hz* : classic mid hump or scoop
*2,500 - 3,000 Hz* : boosting here gives you more snap / pick attack
*3,000 - 7,000 Hz* : Brilliance and Presence / Sparkle
*7,000 - 11,000 Hz* : Treble boost to accentuate distortion
*10,000 - 20,000 Hz* : sort of very high end textural fizz or ’Air’ - pretty much inaudible to most


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## Mcknib

Forgot all about the tone control @BuddytheReow heres a very tiny one

The guy that sent me this @Darrencp tried it with an erupter fuzz said it sounded good  I haven't tried it yet BTW should be easy enough to draw a schematic and try it on the breadboard


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## benny_profane

BuddytheReow said:


> R1 acts as a click-preventing resistor. It cuts out all clicks and other unpleasant sounds from the signal. This part is needed or else the circuit won't work.


The pull-down resistor isn't necessary and the circuit will still work without it. Were you unable to pass signal if you removed it?



BuddytheReow said:


> Input gets biased through R3. Still scratching my head why this is needed but I tried removing it here and the circuit didn't work. So, it stays. Brian Wampler likes to use 470k here for most of his circuits.


You're right that the this sets the bias for the op amp so the virtual ground is 1/2(supply voltage) (i.e., Vref). The resistor provides a path from the buffered voltage divider reference to set the bias of the op amp. This is an AC-coupled circuit, so the bias has be be supplied. R3 is a load that provides a DC return path for Vref and sets the AC impedance.

Here are some resources you might find helpful:





						ElectroSmash - MXR Distortion + Circuit Analysis.
					

The M-104 MXR Distortion + aka Distortion Plus aka D+ is a distortion guitar pedal designed by MXR and released between 1978 and 1979. The original stompbox did not have external power jack or indicator LED. Jim Dunlop bought the MXR licensing




					www.electrosmash.com
				



https://www.renesas.com/us/en/document/apn/how-bias-op-amps-correctly?language=en
(See section 3 for the R3 question and why C4 is required.)


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## BuddytheReow

Will definitely read the bias pdf tonight when I have some time. Maybe my definition of "bias" is incorrect


benny_profane said:


> You're right that the this sets the bias for the op amp so the virtual ground is 1/2(supply voltage) (i.e., Vref). The resistor provides a path from the buffered voltage divider reference to set the bias of the op amp. This is an AC-coupled circuit, so the bias has be be supplied. R3 is a load that provides a DC return path for Vref and sets the AC impedance.


Maybe my own definition of "bias" is incorrect. I will take a look at the link you sent tonight when I have some quiet time to "study". Virtual ground puzzles me too.


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## BuddytheReow

Mcknib said:


> View attachment 14452


On my list to build/tinker!


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## benny_profane

BuddytheReow said:


> Will definitely read the bias pdf tonight when I have some time. Maybe my definition of "bias" is incorrect


I don’t think so? You were just stuck on why that resistor was there. Think of DC bias as the starting point for the DC voltage swing. It’s called virtual ground because it becomes the steady reference for the signal to go above (positive) and below (negative). 

With a +9V single supply circuit, there’s a 9V delta. In order to get the most usable headroom, the reference voltage is put at half that figure (4.5V). This is the ‘virtual ground’ that the signal uses as a ‘home base’ of sorts. If you add a voltage inverter, you can create a -9V rail. In this case, 0V is in the middle and you don’t need to provide a reference voltage via a resistor divider network, just filter the 0V from the supply to deal with ripple. Vref is 0V, the positive rail is +9V, and the negative rail is -9V (and is effectively used as the negative ground supply).


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## BuddytheReow

benny_profane said:


> I don’t think so? You were just stuck on why that resistor was there. Think of DC bias as the starting point for the DC voltage swing. It’s called virtual ground because it becomes the steady reference for the signal to go above (positive) and below (negative).
> 
> With a +9V single supply circuit, there’s a 9V delta. In order to get the most usable headroom, the reference voltage is put at half that figure (4.5V). This is the ‘virtual ground’ that the signal uses as a ‘home base’ of sorts. If you add a voltage inverter, you can create a -9V rail. In this case, 0V is in the middle and you don’t need to provide a reference voltage via a resistor divider network, just filter the 0V from the supply to deal with ripple. Vref is 0V, the positive rail is +9V, and the negative rail is -9V (and is effectively used as the negative ground supply).


Appreciate the input, but still a little confused. I will circle back to this. In my head, biasing a circuit meant changing the 9v to another value using a voltage divider such as in an LPB1. But if I have 4.5v coming out of there and I throw a 1m resistor after that the voltage drops to nothing and THAT's what goes to the input pin in the IC? Again, I have to relearn some of the boring theory behind it all.


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## BuddytheReow

I took some time this afternoon to try out a tone stack (treble, mid, bass). Marshall Guv’nor seemed like any place to start. Here’s the schematic 




It seems simple enough on paper, but it took quite a while to figure it out on a breadboard. Because this is a passive tone stack that throws certain frequencies to ground it needed a booster at the end. Going to try different tone stacks soon to see what I like. I’ll also try it with some op amps now that I kinda know how they work.

Without further ado, I present an Electra distortion with variable gain and diode selector (4148s or red/green led) into a Marshall guv’nor tone stack into an lpb1. You can kinda see the 3 sections on the breadboard how I laid it out.

I call it the “Crooked President”.


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## benny_profane

Check this site out if you haven't already:



			TSC in the web


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## benny_profane

BuddytheReow said:


> Appreciate the input, but still a little confused. I will circle back to this. In my head, biasing a circuit meant changing the 9v to another value using a voltage divider such as in an LPB1. But if I have 4.5v coming out of there and I throw a 1m resistor after that the voltage drops to nothing and THAT's what goes to the input pin in the IC? Again, I have to relearn some of the boring theory behind it all.


Biasing can _involve _that, but it doesn't mean that necessarily. All you're doing it establishing a known, stable operating point for an active part, circuit block, or whole circuit.

The voltage doesn't drop to nothing when it goes through the Rin resistor (1M in the case of the discussed circuit). Note that it's unusual to have those values in the voltage divider and the input resistor (that's discussed in the electrosmash article and the linked pdf). Essentially, that resistor has two purposes: 

1) Provides a load that determines the input current to the op amp.
2) Sets the input impedance to the circuit.

Check out this resource (particularly Figure 4.3.2 and the inclusion of _R5_) for a more detailed breakdown with example circuits.


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## BuddytheReow

benny_profane said:


> Biasing can _involve _that, but it doesn't mean that necessarily. All you're doing it establishing a known, stable operating point for an active part, circuit block, or whole circuit.
> 
> The voltage doesn't drop to nothing when it goes through the Rin resistor (1M in the case of the discussed circuit). Note that it's unusual to have those values in the voltage divider and the input resistor (that's discussed in the electrosmash article and the linked pdf). Essentially, that resistor has two purposes:
> 
> 1) Provides a load that determines the input current to the op amp.
> 2) Sets the input impedance to the circuit.
> 
> Check out this resource (particularly Figure 4.3.2 and the inclusion of _R5_) for a more detailed breakdown with example circuits.


Thanks, Benny. I'll check these out with some light reading


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## BuddytheReow

My Tayda order came today!! I took some time to whip up a "protoboard" with my order and some items lying around the house. @fig had a great idea regarding potentiometers from a previous thread found here. Previously I used solid core wire soldered to the pot and found that it _kinda _worked. If I were to turn the knob the connection would go in and out. Thanks for the tip, fig! This daughterboard will definitely help. I've got extra room on it and thinking maybe a separate power section with a voltage divider? May be worth my time.

Also wondering how I can mount a few switches as well to make it more "permanent" on the daughterboard. If anyone can chime in here that would be great.

Mounted everything with some putty for now and so far it holds. I know this is kinda ratchet looking (a term my wife uses a lot) using cardboard and duct tape, but this is temporary until I make a trip up to Home Depot to get a piece of lumber and finish it. What size should I get? 8x12?









						IMG_0699.HEIC
					






					drive.google.com
				











						IMG_0698.HEIC
					






					drive.google.com


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## BuddytheReow

Not all breadboards are created equal!!!! You can see in the pics of my previous post that there are 2 different breadboards: my new one from Tayda and other one from "Elegoo". I'm assuming the later is a cheap, Chinese knockoff and it shows! It is the whiter one of the two. Many of the holes were tough to put jumper wires in and various component leads. Some of the pins came out of the jumper wires while removing them from the board and I was careful!!! This other one from Tayda is much nicer and all the leads/jumpers fit nice and snug, but not overtight. 

Lesson learned...


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## BuddytheReow

Still fooling around with some tone stacks.

This is a Ross Distortion (very similar to MXR Dist +) with some mods. First, a negative feedback loop capacitor selector (between 47n and 22n and I like the 22n better). Then an asymmetrical, hard clipping diode selector (4148s and Red LEDs) into a Baxandall Tone stack. This tone stack was easier to figure out the layout than the guvnor one I did the other day. Prolly cuz there's only 2 pots instead of 3.

Does this make it more original rather than putting stock building blocks together? I'd like to think so, but I'm far off from a true original circuit. Would love some comments, but if not, that's fine. This thread is merely me writing down my thoughts, knowledge obtained on the internets, and tinkerings.

Here are some pics of the breadboard. I definitely gotta find a way to clean up all those jumper cables. Looks like a rat's nest. I guess part of the breadboard learning experience is changing the layout to reduce them. Or I find shorter cables.


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## BuddytheReow

Looked around PedalPCB site and decided to try out the Heavy Spider (Epider Sound Heavy Metal). Simple circuit and schematic below. Since I've been doing a lot of reading lately I have a _basic_ understanding of how this circuit is put together and what part does what.




I put switches on both sets of diodes to hear the difference in clipping. Noticeable volume drop in the hard clipping section (D3 and D4). The soft clipping section (D1 and D2) was too subtle for my ears. Perhaps I didn't wire the switch correctly? Anyway, this has an interesting sound. There is a bit of gating, but not too much; just enough to give it some flavor. I found the sweet spot by rolling back the volume knob a bit and adjusting the "attack" knob a bit. In my opinion, this dooms...


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## benny_profane

BuddytheReow said:


> The soft clipping section (D1 and D2) was too subtle for my ears.


Those aren't soft-clipping diodes. That's a crude noise gate / noise reducer that results in crossover distortion. The same scheme is used in the Boss HM-2.


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## BuddytheReow

benny_profane said:


> Those aren't soft-clipping diodes. That's a crude noise gate / noise reducer that results in crossover distortion. The same scheme is used in the Boss HM-2.


Either way I couldn’t tell the difference with them. How do I know that’s a gate/noise reducer? Simply because there are 2 diodes going opposite ways? I guess I’ll have to do some reading about the hm2. Thanks for pointing that out to me!


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## benny_profane

Soft clipping diodes are in the feedback loop of an op amp gain stage. These are in series with the signal and set a baseline for the signal to pass. For example, if the Fv of the diodes is 600mV, only signals above that threshold will pass because they are arranged in anti-parallel. The issue with that arrangement is that it creates crossover distortion when the signal passes from positive to negative and vice versa. There's a lot of other distortion happening in the circuit, so that won't be the dominant sound, but it is there. The main purpose is to create a noise gate and reduce transients.

I think that the ATTACK knob reduces the parallel resistance and lets signal bypass the diodes as it's turned up. In that case, the gating effect would be lessened and the pick attack more apparent as it's turned.


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## BuddytheReow

benny_profane said:


> Soft clipping diodes are in the feedback loop of an op amp gain stage. These are in series with the signal and set a baseline for the signal to pass. For example, if the Fv of the diodes is 600mV, only signals above that threshold will pass because they are arranged in anti-parallel. The issue with that arrangement is that it creates crossover distortion when the signal passes from positive to negative and vice versa. There's a lot of other distortion happening in the circuit, so that won't be the dominant sound, but it is there. The main purpose is to create a noise gate and reduce transients.
> 
> I think that the ATTACK knob reduces the parallel resistance and lets signal bypass the diodes as it's turned up. In that case, the gating effect would be lessened and the pick attack more apparent as it's turned.


Gotcha. Your explanation makes sense. I thought the attack knob was merely a tone filter. Still a little confused if cap/resistor are in series if it's a high or low pass. More reading for me I guess.  Thanks, Benny


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## BuddytheReow

Going to be tweaking the Heavy spider shortly, but I wanted to share a “tool” that I built over the weekend. I shared previously a big muff tone stack which is a great multi purpose tone stack given the few number of parts it needs. The problem with that is it’s a passive filter and sucks out a lot of volume.

what’s the solution? Build a booster after it! This comes from tagboard and is a BMP tone stack with an LPB-1 booster. The trimmer is merely the output volume and obviously can be adjusted to taste. Although it is a stripboard layout I have slightly modified it by putting sockets where the power, ground, input, and output wires go. Jumper cables fit surprisingly well on them. To help me identify which socket is which I have labeled them. For the power socket I simply used a bit of my wife’s nail polish carefully on the sides and top.

definitely useful when breadboarding a circuit and realize the sound is not quite right…


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## BuddytheReow

Using my newly created toy, I tacked this on to the heavy spider still sitting in my breadboard. Added at the end of the circuit right before the volume pot. I also added 2 gain controls, one on each emitter going to ground. I also took out the diode switch near the “attack” pot since @benny_profane mentioned this is merely a noise filter. The hard clipping diode switch still remains.

after playing around with it I think I have dialed everything in to my taste and am happy with the sound. Gain 1 should remain as is in the circuit (emitter straight to ground) gain 2s sweet spot to me is around 560 ohms.

sorry about the crappy camera work. I only have my phone.

Edit: video link here. I only changed the diode clipping switch.


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## fig

How's that pot-board working? That's slick! 
I think Chuck mentioned something about grounding the pot housing to reduce noise in _sensitive _circuits, but my bench, room, house, has so much noise it causes tinnitus anyway.....my plan is to line the walls, floor, and ceiling with copper and solder my pinkie toe to it. 

I am ground! [using Groot's voice]


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## BuddytheReow

Pot boards working great.  No issues so far. Definitely more room for switches, etc.
Edit: How would I go about grounding the pot board?


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## BuddytheReow

Question for you all!!

I'm currently breadboarding a Distortus Maximus (will put together a Biggus Dickus shortly  ). According to Chuck, this is is an LPB1 into a LM386 into a Marshall TMB stack, and I agree. I've only breadboarded the LBP1 and the LM386 and the circuit works. Instead of adding the TMB stack I put it directly into my BMP/LPB1 stripboard tool after the output pin and get this HIGH PITCHED WHINE on top of the signal and can alter the pitch of the whine with the pot. It almost sounds like RF waves. *Why does this happen?* Is this a specific breadboard issue or circuit design issue? Here is where I put the tone stack and marked it in BLUE.

Edit: Turning off my overhead fluorescent lights and turning off my phone doesn't change the issue, so I don't think it's an antenna issue? I also breadboarded a simple Bazz Fuss with the BMP stack after it and it worked just fine. It seems to be circuit design issues, but am not going to worry too much. Will try tacking on a baxandall instead of the Marshall TMB and report back with some other mods...


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## BuddytheReow

This is more of a "Look What I Built!" post than anything else...

I built the Distortus Maximus pedal sans TMB tone stack and liked the sound of it. The LM386 chip was not specifically designed for a distortion pedal, but it is used here. I added on a Baxandall tone stack after the 386 for tone tweaking.

Then I looked at the booster stage, which is an LPB1. IMO it's ok not great for a clean booster unless you have single coil pickups. So....I decided to swap that out and put in a Black Tiger Boost. I changed the pot from a 50k to 100k for more gain (OMG so metal 🤟). In hindsight I could have also removed the 50k Gain pot on the Distorus Maximus since it's merely dumping the signal to ground before the LM386 stage, but I got a little lazy since it was already wired up and I can just keep it open. The Black Tiger Boost almost could have been removed from this circuit entirely, but it adds a bit more "creaminess" to the overall sound.

In summary:

IN ->Black Tiger Boost -> LM386 portion of Distortus Maximus -> Baxandall Tone Stack ->Hard Clipping Red LEDs (switchable on/off) -> OUT

As I'm writing this up this really isn't a single distortion pedal, it's a pedal train! Nearly each of the stages here can be boxed up individually minus the diode clipping at the end.

I call it _El Tigre Distorsionado_ which means "the distorted tiger".

Edit: Yes, I know I have a whole other board I could have used and yes I know you can barely see the components due to the 2394832742 jumper cables.


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## fig

Man, that's a wild ride for sure! Nicely done!


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## Chuck D. Bones

Why do breadboards oscillate?  In the simplest terms, it's because there is stray coupling in places where it doesn't belong. 
I'm surprised when I build a high-gain circuit on a breadboard and it _doesn't_ oscillate. 

It's important to have solid grounds everywhere.  None of this single-point ground nonsense, ground everything to everything else. 

Power supply bypassing is critical.  That 0.1uF cap should go directly from pin 4 to pin 6 of the LM386.

Keep inputs and outputs away from each other.  Move the GAIN control away from the other controls and run its ground separately back to pin 2 of the LM386.  Arrange your breadboard to flow like the schematic.  Keep the wires short and separate them.

Do you have a schematic of the whole thing?


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## BuddytheReow

I'll write something up by hand tomorrow for the finished build. I haven't even attempted to learn any CAD software for schematics. Not yet at least...

That final build did have a ton of gain and I heard the slight humming, but not the squeal when I tried to tack on a BMP tone stack right after the 386.


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## Chuck D. Bones

Try TinyCAD.  It's free and pretty easy to use.  I can help.


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## BuddytheReow

For you viewing pleasure of El Tigre Distosionado. This is my first time using CAD software. Was pretty simple using TinyCAD. Thanks @Chuck D. Bones !


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## Chuck D. Bones

Not bad for the first time out.  I can see what you're doing.  I noticed a few typos:

You need a series resistor and cap between U3A's output and the LED clippers.
R13 & C13 should connect to the output of U3A, not the - input.
C10 and C11 should connect to pin 2 of the Bass pot.
You don't need R6 or R8 (replace with jumpers) or R9 (omit).
There should be a cap in series with R7.
You have the + and - inputs swapped on U1B.
You can drag the value and ref des for each part so they line up better next to that part.

I ended up editing several of the parts in the libraries to make them prettier.  That's a nicety and something you can do when you get more comfortable using TinyCAD. 

Good job!


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## BuddytheReow

Good catch, Chuck. Appreciate the compliments for a CAD noob. I have made the changes here. The capacitor in the negative feedback loop in U1b I'm still leaving blank since this is virtually a part for part of the Black Tiger Boost.


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## BuddytheReow

Piggybacking on the recent build, I took a look at the LM386 itself and wanted to know a bit more about it and why it's so unique. It's actually a power amplifier!! Want to hear why it's so special? Let's build it!

I took a look at the 'El Sol Distortion' which is based on the EDQ Acapulco Gold and realized it's merely a LM386 into another LM386 with some slight filtering. I wanted to know what a single LM386 sounds like so I stripped it down.

You may follow along in the schematic or my breadboard pics.




Pins 1 and 8 are jumpered together. THis is the gain control of the chip and we want it maxed out for right now  🤟
Pins 2 and 4 go to ground
Pin 3 is input
Pin 5 goes to an electrolytic cap. I chose a 4.7u. This is to filter out the DC in the circuit.
Pin 6 goes to 9v

And that's it!

Well, technically yes, but when I tried it there was a lot of "gating" when I strummed real hard. So, I decided to tone that down a bit.

Change the input to the following: Input to 10k resistor to pin 3. I also put a 100k resistor from the out of the 10k to ground.




Behold the raw power of the LM386! Honestly, it's $@^$(@ loud and gnarly! A very distinct sound indeed. If you want you can add hard clipping diodes after the 4.7u cap to ground and then to output. There is a subtle difference, but its there. Edit: Make sure you put a resistor before the diodes otherwise you may fry them. I suggest 10k.

The more you know


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## benny_profane

Does anyone know why most pedal applications of the LM386 merely short pins 1 and 8? The datasheet indicates that there should be a 10uF cap for gain = 200.


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## Chuck D. Bones

Going back to the v1.2 schematic, I think you have R3 & R4 switched.

If you get any scratching when you rotate the GAIN pot, then that cap I suggested will fix it.  Make the cap 1uF or larger and it won't change the tone.

Comments on your last post, in no particular order...

If you put clamp diodes on the output of the 386 (after C1, of course), then you need a resistor in series with C1 to limit the diode current.  The LM386 is a power amp and will deliver an overdose of current to the diodes.

You should really have a cap in series with the 10K.  The 386 inputs are biased internally and your guitar was upsetting the bias.  The 10K helped, but is not a good solution by itself.


----------



## Chuck D. Bones

benny_profane said:


> Does anyone know why most pedal applications of the LM386 merely short pins 1 and 8? The datasheet indicates that there should be a 10uF cap for gain = 200.


The cap is preferred, but not required.  The cap helps keep the 386's output centered for maximum headroom.  Not a big deal with dirt pedals because we don't need that last little bit of headroom.  Three are a few different ways to vary the gain.  Check how I did it on the Biggus Dickus for an example of another way.


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## BuddytheReow

Chuck D. Bones said:


> Going back to the v1.2 schematic, I think you have R3 & R4 switched.
> 
> If you get any scratching when you rotate the GAIN pot, then that cap I suggested will fix it.  Make the cap 1uF or larger and it won't change the tone.
> 
> Comments on your last post, in no particular order...
> 
> If you put clamp diodes on the output of the 386 (after C1, of course), then you need a resistor in series with C1 to limit the diode current.  The LM386 is a power amp and will deliver an overdose of current to the diodes.
> 
> You should really have a cap in series with the 10K.  The 386 inputs are biased internally and your guitar was upsetting the bias.  The 10K helped, but is not a good solution by itself.


To keep the raw signal, what value cap would you suggest to go with the 10k resistor?

I edited my previous post to include a resistor before the diodes.


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## BuddytheReow

Adding v1.3 of El Tigre Distorsionado with Chuck's r3/r4 comment.


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## benny_profane

Chuck D. Bones said:


> The cap is preferred, but not required.  The cap helps keep the 386's output centered for maximum headroom.  Not a big deal with dirt pedals because we don't need that last little bit of headroom.  Three are a few different ways to vary the gain.  Check how I did it on the Biggus Dickus for an example of another way.


That all makes sense. I didn't know if that was just there for centering of if it also provides stabilization to prevent oscillation. The implementation in your BD is interesting. I'll have to dig into that a bit more to understand what's going on.


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## Chuck D. Bones

The datasheet includes a schematic.  Unlike the usual opamps, the LM386 contains the negative feedback components inside.  Pins 1 & 8 tap into that feedback path and allow us to tweak it.


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## Chuck D. Bones

BuddytheReow said:


> To keep the raw signal, what value cap would you suggest to go with the 10k resistor?
> 
> I edited my previous post to include a resistor before the diodes.


I'd use a 220nF or larger film cap.


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## benny_profane

So, if I'm understanding correctly, what you're doing is adding an emitter resistor/cap to GND on the PNP darlington pair on the non-inverting input. I get that the topology is a long-tailed pair, but I think I'm confused because it seems that the +input has both the collector and emitter referenced to ground?


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## Chuck D. Bones

I gotta run, I'll explain it later if someone else doesn't.


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## fig

I'm gonna go out on a limb and say I have no earthly idea.


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## BuddytheReow

Yea, I haven't looked into the chip itself and what's under the hood. I just know how to hook it up (kinda) and what it sounds like.


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## benny_profane

BuddytheReow said:


> Yea, I haven't looked into the chip itself and what's under the hood. I just know how to hook it up (kinda) and what it sounds like.


The datasheet has a lot of great information.


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## BuddytheReow

Look what I built! This was my project over the weekend. I found some scrap wood in my attic and decided to make a board for my breadboard. I couldn't tell if it was pine or cedar (not super knowledgeable), but I knew it wasn't oak cuz it wasn't heavy. I used some cherry stain I had leftover from my guitar build and decided to put it to good use. Sanded it down as best I could with my orbital sander, 2 coats of cherry stain, and 3 coats of poly. Now I can "show off" some of my builds without it looking super ratchet, lol.

If anyone's curious, those are 2 overdrives sitting on the board: one is a tubescreamer I'm experimenting with.

I also had a few mod boards from GuitarPCB come in today so I will post again once I've got them ready to go. Thanks @thewintersoldier for this suggestion! They can be found here https://guitarpcb.com/product/dpdt-wiring-board/. I'm also trying to figure out the rotary board from there too since it seemed pretty cool. Will have to use my DMM to figure that out when I have time.


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## Chuck D. Bones

benny_profane said:


> So, if I'm understanding correctly, what you're doing is adding an emitter resistor/cap to GND on the PNP darlington pair on the non-inverting input. I get that the topology is a long-tailed pair, but I think I'm confused because it seems that the +input has both the collector and emitter referenced to ground?


Here's the schematic for reference.



Most circuits using the LM386 ground the -INPUT.  It could be left floating, but might pick up noise or RF interference.  That leaves the emitter of Q2 biased at 2 Vbe above ground.  Q5 and Q6 form a current mirror; they try to keep the collector currents of Q2 and Q3 equal.  R2 biases Q4's base close to ground, so Q3's emitter is biased to about the same voltage as Q2's emitter.  Because Q2-E and Q3-E are at nearly same voltage, very little DC current flows thru R5 & R6.  All this leads to the fact that the DC current thru R3 & R4 is about the same as the DC current thru R7.  Notice that R3 + R4 is twice the resistance as R7, so the voltage drop across R3 + R4 is twice the voltage drop across R7.  The only way that can happen is if Vout is close to 1/2 Vcc.  The negative feedback thru R7 ensures that Vout  = 1/2 Vcc.

With pins 1 & 8 open, the AC and DC gain of the LM386 is 20x. Any small DC imbalances in the Q1-Q6 circuit is magnified by 20x and appears at the output. With pins 1 & 8 jumpered together, the AC and DC gain of the LM386 is 200x.  Any small DC imbalances in the Q1-Q6 circuit is magnified by 200x and appears at the output.  But... if we connect a capacitor between pins 1 & 8 instead of a jumper, then the AC gain is 200X but the DC gain stays at 20x.  Less DC offset on the output.


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## benny_profane

@Chuck D. Bones Thank you for the detailed explanation. I’m still a bit confused regarding the topology of the BD. In the BD, you have pin 1 grounded via a resistor and cap. How are the AC and DC gains affected with that arrangement? Does that increase the amplification by further increasing the DC offset?


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## BuddytheReow

Really digging this 386 analysis! Great stuff


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## Chuck D. Bones

What I did in the BD has a similar effect to bypassing R6.  I didn't invent that method.  It's convenient if you want a gain other than 200x.  The cap is mandatory because pin 1 is not at DC ground.

It increases the AC gain without affecting the DC offset.


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## benny_profane

Chuck D. Bones said:


> What I did in the BD has a similar effect to bypassing R6.  I didn't invent that method.  It's convenient if you want a gain other than 200x.  The cap is mandatory because pin 1 is not at DC ground.
> 
> It increases the AC gain without affecting the DC offset.


Ah okay. It’s starting to make more sense now. Thanks again!


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## BuddytheReow

Took some time last night to put together my 2 mod boards. One is a dpdt mod board, the other is a 2p4t rotary mod board. I've got 2 extra dpdt boards and maybe bring them out at a later time. I socketed _everything_ and took a lot more time than I thought. Since the board itself had the wiring/pinout diagram on it and got covered up with all the sockets I decided to color coordinate everything with a bit of nail polish (thanks, Babe  ). I've been interested in mosfet clipping for a bit now so maybe I'll rebuild the Dist + with tons of clipping options to see what sounds good/bad.


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## BuddytheReow

Like a kid in a candy store with allowance money in his pocket, I was itching to use my new mod boards. What's one of the more simple dirt pedals to mod? The MXR Dist +, of course! Here is a simple schematic taken from Beavis Audio. The original opamp is a 741 (single opamp) and has a different pinout than the 4558 listed here, but we are only using one of the opamps and they behave similar.

To give the high level view of this circuit, it is a Dist + with switchable feedback capacitors, on/off soft clipping diodes, increased gain potential, switchable hard clipping diodes, and a BMP tone stack thrown on toward the end. I would consider this a modified, but more modifiable circuit.
Items in purple are what I swapped out or made switchable and will explain below. The red areas are where I added things.



For the reds, in the feedback loop I added asymmetrical clipping 1n4001 diodes and made it switchable on/off. Using these had a noticeable volume drop and was very subtle in tone, but that is the nature of soft clipping. Turn the gain back and you've got an overdrive! Cleans up nicely with the volume knob on my LP and Strat.

The other red item after the hard clipping diodes I added my BMP tone stack w/LPB1 booster that I shared in a previous post. The booster itself is only used to bring back the volume drop from the tone stack. Here is the schematic for the tone stack itself and is very simple, but effective.




Now the purples:

I swapped out the 1m resistor for a 1.8m for more gain 🤟. Was happy with the sound so I left it there. Of course you can go higher if you want and see what happens...

For the 4.7n cap I decided to whip out my rotary mod board for this. The purpose of this capacitor is to decide which frequencies get passed through to the opamp and amplified. Since my board had 4 spots I chose the following values: 10n, 33n, 100n, and 330n. The larger the value, the more bass comes through. If you want to get more specific in choosing the specific frequency for the cutoff you will have to adjust the 4.7k resistor accordingly. It can be tacked on to the mod board too if anyone's interested on the outer sockets with additional jumpers.

The other area _begging_ to be modified was the hard clipping diodes. I used my DPDT mod board and found 2 combinations of diodes I liked: one is a BAT41/1n4148 and the other a red LED/1n4148. LEDs give a volume boost for some reason and my curiosity wants me to dig around the interwebs to find out why.

I am very pleased with the tonal possibilities of this circuit and am debating whether to commit this to stripboard or to come back to it another day. Breadboarding is slowly becoming an addiction for me once I begin to understand how circuits work.


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## benny_profane

BuddytheReow said:


> LEDs give a volume boost for some reason and my curiosity wants me to dig around the interwebs to find out why.


Since the Vf of the LEDs is higher than that of the BAT41 and 1N4148, less of the signal is clipped and a higher amplitude signal is allowed to pass. You're experiencing that as more headroom before compression and a higher volume level.


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## Feral Feline

Or to put it another way, the diodes are dumping signal to ground and the order of magnitude from most to least is:
Bat41
1N4148
Light Emitting Diode

Like a leaky garden hose, the less water that's leaked to ground the more pressure and volume of H2O gets to the sprinkler's output.


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## BuddytheReow

More tone stacks! This is a Marshall TMB tone stack with an LPB1 booster afterwards as a recovery. Found the stripboard layout on the interwebs. My new tool, er, toy. I mean tool, yea. Gotta keep it semi adult around here.

My project this evening. Feel free to copy. Works great!


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## BuddytheReow

In an above post, I had a Dist + circuit with a capacitor selector. Sometimes I liked the "thin" sound with the smaller cap, but it was actually too thin. The opposite is true too: I had a larger cap that I like the deep bass coming through, but it was a bit too muddy.

What's the solution? Blend the two with a potentiometer! The little lightbulb went on for me when I was looking through various build docs and stumbled upon the Dingo Distortion circuit. This FAT pot allows you to blend the sound between the two filters produced with the 220n and 1u capacitor.

Depending on the circuit you may have to fool around with different tapers and values to find one you like best.


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## BuddytheReow

I've been taking some time to look at 8245039349002 schematics out there and I thought this one was interesting. This is a PCB from Rullywow called the SuperJudge. I whipped this up on a breadboard and it's a decent higher gain overdrive if anyone's interested in the sound.

I'm posting this here because when I was looking it over I noticed something interesting. This build requires a 1044 charge pump and for the life of me at first I couldn't understand why. Charge pumps are _usually_ used to increase the voltage on many circuits that I have come across, but not always. This one utilized the -9v output so I thought "hey, why is this so special that it's using -9v?".

The answer became obvious after I breadboarded it and troubleshooted it (C3 was placed in the wrong hole on my board so user error).

Many times on opamp dirt circuits you will have a voltage divider in the power section (4.5v). THAT'S what goes to the other opamp input to bias the circuit, whether the positive or negative one (inverting or noninverting if you want to get technical). When I looked the circuit over again it dawned on me: the + input in both opamps goes to ground (0v) and that's EXACTLY midway between 9v and -9v that powers the circuit which acts as the bias!!

I thought this was interesting because it's another way to bias opamps rather than voltage divider resistors and should go in my "notes" thread. I don't have a breadboard pic unfortunately since I wanted to try another circuit over the weekend, but this is pretty simple to whip up if you've got some experience.


----------



## music6000

Feral Feline said:


> Or to put it another way, the diodes are dumping signal to ground and the order of magnitude from most to least is:
> Bat41
> 1N4148
> Light Emitting Diode
> 
> Like a leaky garden hose, the less water that's leaked to ground the more pressure and volume of H2O gets to the sprinkler's output.


Feral, I would use a large resistor to stop the hose leak from *popping* any further!!!


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## Feral Feline

music6000 said:


> Feral, I would use a large resistor to stop the hose leak from *popping* any further!!!


Sorry, I'm not following this. Are you talking about switch-pop at the output? I was referring to hard-clipping to ground; you could add a resister in series with the LEDs to ...  wait, is that a euphemism?


----------



## music6000

Feral Feline said:


> Sorry, I'm not following this. Are you talking about switch-pop at the output? I was referring to hard-clipping to ground; you could add a resister in series with the LEDs to ...  wait, is that a euphemism?


My mistake, I thought you had a leaky hose!!!


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## BuddytheReow

Tayda order came today!!! An extra breadboard, some terminal block, PCB mount switches, and header pins. Was time to update my breadboard rig even more today.

Here's my rig as of right now. Look at what I made!!!!!!!!!

Test Box w/ built in audio probe. Found this on tagboardeffects
3 Breadboards
DPDT mod board from Guitar PCB - Very handy for diode selection or A-B'ing a cerain component
2P4T Rotary mod board from Guitar PCB
And my daughterboard consisting of:
-8 Terminal Blocks for PCB mount potentiometers with header pins for breadboard jumper mounting
-2 DPDT switches with header pins for breadboard jumper mounting

My daughterboard has been upgraded to a *MOD-ERBOARD*_._

The circuit on there is from an earlier post I made today: PedalPCB's Acid Rain Fuzz. It's pretty good and worth your time breadboarding it, but it probably won't look as cool as mine does


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## fig

That's fantastic!


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## BuddytheReow

Here’s a little breadboard tidbit I learned today. In my post about Breadboards 101 I mentioned that the power rails marked blue or red go all along the board on both sides. Not all breadboards are like this!

I picked up this breadboard from Tayda and noticed there was no power going from one set of power rails to the other even with a jumper wire going across the board. At first I thought I got a bad board. Lo and behold I noticed that the power rails get cut mid way down the board. You can see that the colored lines are cut showing this as well. Why have this? Off the top of my head you may want to do 2 separate input voltages (9 or 18v). Other than that I have no idea. The simple solution to this “problem” is to simply jumper them. I used solid core wire and it fixed it right up. Now all my breadboards act the same!


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## BuddytheReow

Welp, I think I found my limit. I thought my breadboard platform would provide nearly unlimited builds. While this is still true I forgot to figure in user error. My "protoboard" has 3 boards on it and I thought I could work on 3 projects simultaneously. Turns out after 2 things start getting really messy. Especially when I start crossing jumper wires for the various pots. It's always that 3rd build that starts giving me problems.

Not sure if I should post this here or at the Loafing Lounge thread.

Here are 2.5 projects before I called it quits: a MuffRat (schematic below and a nice med/high distortion), my L-PB&J Sandwich, and an attempt at Jack Orman's Son of Screamer. I gave up after the gain stage. Now comes the crappy part of taking it all down


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## BuddytheReow

This is more of a rant/complaint than anything else....

First, I'm really enjoying breadboarding. I really enjoy building a circuit from scratch either by following a schematic, modding something, or from the ground up with basic circuit blocks. I haven't really picked up a soldering iron in weeks months now, but I plan on it soon...

I have 2 complaints when it comes to breadboarding:

1. When I'm finished with a breadboard project and happy or not happy with the circuit I have to clean up. Booooooo! Very few of us like cleaning up. Putting all those resistors back in their bags/drawers/compartments, making sure the correct value component goes back where it should, taking the jumper wires out, etc. It's annoying. The solution is to buy more breadboards   

2. Where I put circuits together and where I play are on opposite sides of the same room in my basement. I think I've finished a circuit, walk it to the other side of the room, turn on my amp, plug in the guitar, plug in the jumpers on my test box (always on my board now), hit the stomp switch and...nothing. Ok, now I've got to back to my workstation, get my multimeter, get my tablet if a schematic is on there, and go back to my play area to start troubleshooting. Oh, I forgot a jumper cable _there_? How stupid of me! Back to my workstation for a cable. Yadda yadda yadda... I tend to repeat this process more times than I'd like since I test my circuits in stages (first gain stage, after clipping, after tone control, etc.) to make sure everything works. Maybe you guys are in the same boat too with this even though you're soldering? I would love to have a small amp and cheap guitar at my workstation, but I don't have the room. Correction, I do have the room but the layout of our basement doesn't allow this: our home "gym" is in between.


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## BuddytheReow

I've been stalking around Jack Orman's site http://www.muzique.com/ for a while and decided to go through his lab notebook. I chose his Saturation Control page to see how you can change the clipping depth of many circuits that use diode clipping. These are hard clipping circuits, not soft clipping. I would be curious to see how they could be done in, say, an opamp feedback loop but I don't think these ideas here can be transferred part for part. You would be adding resistance to the fb loop and would affect the gain. You can read his article here and all credit for this is to Mr Orman himself.

What's a simple circuit to try this out on? Why, the MXR Dist + of course! I chose to use the schematic taken from Beavis Audio's beavisboard project found here. If you're wondering how to whip this up on a breadboard it shows how to do that as well. Schematic is posted below. For purposes of this experiment I stopped building after C6. A volume pot is not necessary if I'm just experimenting. Plus, I tend to dime most of my dirt pedal volumes anyway. I also modded the circuit a bit too: change C2 to 100n and C4 to 100n. These 2 mods allow a LOT more bass to get through and gives your tone some balls!




Jack's article has 9 variations of the saturation control and I chose to experiment out of order than the article reads. I will label them 1 through 9 if anyone wants to follow along with my notebook/blog here. If there is a capacitor in the examples below right at the input I didn't breadboard them since I've already got an electrolytic already in there (C6). It's merely there as a coupling capacitor (I may write up something about capacitors soon).

First up is example 1. This is the basic saturation control.



I used 1n4148 diodes since they are the "standard" clipping diode IMO. When turned ccw there should be less resistance going to the diodes from the input signal and it should sound harsher per his article. When I tried this out it was VERY subtle turning the pot in either direction, but it is there. Even tweaking the gain pot of the Dist +didn't change the clipping sound that much. The sound is still very usable though. Oh, I should also mention if you've got the gain pot maxed out there will be clipping BEFORE the saturation control. This clipping happens in the opamp itself.

I then tried example 2.



Still using the 1n4148s, this is almost identical to the first example with the exception being that you're controlling only 1 of the diodes. I found this one to be a little less subtle that the first example, but it is still pretty subtle. This one controls the clipping on the negative peaks of your signal.

Jumping down to the end of the article I went with example 9.



The pot here is a blend control going back and forth between a pair of hard clipping diodes and your raw guitar signal. The purpose of this is to provide some more subtlety that a simple on/off switch to select the diodes. The pot here would be the equivalent to using hot sauce: sometimes you want a lot and sometimes you only need just a little something. I kind of liked this one and may use it on a future project.

Working backwards I went to example 8



This pot is also a blend control between hard clipping diodes and a low pass filter (gets rid of the highs). Since I wanted to hear the full effect of the blend control I modded the Dist + circuit back to schematic stock values (only 2 capacitors and took me all of 30 seconds, if that). It's a very treble oriented circuit so this blend control seemed interesting to try. Lo an behold, it is!! Turning it fully ccw is the full clipping and very harsh sounding and as you dial it to the right you start taking off those nasty, ear piercing highs. Since it's a passive tone filter here there was a bit of volume drop. 

Example 7



Like the previous example, this one blends clippers and now a _high_ pass filter. To get the most out of this one I remodded the circuit (C2 and C4 to 100n). As you turn the knob to the right you start bringing out the highs in your tone to give it a bit of "sparkle" as said in the article and I agree wholeheartedly. This one is great to put into a DIY circuit IMO. Then again, Jack says this one would be great in a Dist + circuit, so go figure.

Example 3. Now we go into something called _crossover distortion_ (sounds cool, right?)



The article suggests to use germaniums or schottkys to get the full effect, so I decided to use BAT41s. Honestly, I couldn't hear anything when going back and forth with the pot. I tried dialing back the gain a lot on the Dist + and couldn't hear anything. I guess I need to try this on a different circuit.

Example 4.



A crossover saturation control also attached to a LED (chose a red one). I tend to like the sound of red LEDs as clippers: less compression and more volume. However, I couldn't hear a difference in sound using the saturation knob. I'd like to think I did, but who knows?

Example 6



Blending hard clippers and crossover distortion. Despite the volume drop going toward the clipper side, I can honestly say I DO hear the crossover distortion when dimed to the right. It's very subtle, but it's there. To me it almost sounds like the tiniest amount of soft clipping, but not quite.

Example 5. A simpler variant of the above.



Altering the behavior of the same pair of clippers to act as either hard clippers or crossover distortion. It sounds very similar to the previous example and am relatively unimpressed. I'd rather use the hard clipper/full signal one instead.

My thoughts based on the above:

-I don't get crossover distortion. When I tried to hear it via youtube everyone just points to the oscilloscope showing its occurring and I hear very little change. Maybe because I'm just using my laptop speakers.

-General saturation controls and to add subtlety, nothing more. If you're a tone snob, and we all are to some degree since tone is subjective, you may want this.

-My best takeaway from this was the blend controls between the hard clippers and a RC filter of some kind, whether it be a high pass or low pass. These controls are also the most noticeable out of the 9 examples above. Sometimes you only need one tone knob to get a good sound and why not incorporate some clipping in there too.


----------



## BuddytheReow

Darlington/Sziklai Transistor pairs. Some good theory that opened up a world for me for circuit analysis.

I had a brain lightbulb go off recently. Actually it was last night when I was reading up on some circuit analyses and someone mentioned a "Darlington transistor pair" in a YouTube video so naturally I stumbled further down a rabbit hole. Once everything 'clicked' I realized how useful this can be and how common this is in many circuits.

(Small) Bear with me here...

A Darlington transistor pair consists of 2 transistors (either NPN or PNP) linked together that act as one whole transistor. The output of one transistor becomes the input of the other transistor. The schematics for either set are shown here




When linked as such, their common connections become one whole unit and the "new" collector/emitter is created.

The result? Increased current gain, and not just a simple 1+1=2. The product of the gains of each transistor becomes the total gain of the unit. If you're using 2n2222s with a gain of around 100, the gain of the darlington unit becomes 100 x 100 = 10,000 in theory. 

There are a few disadvantages to using this. First, you have to have an input voltage large enough to make the circuit block work (voltage drop). Each transistor has its own voltage drop (~0.6v) so you'll need an input voltage of 0.6 x 2 = 1.2v. Not a big deal, but its there. The other disadvantage is that this circuit block becomes relatively unstable as the input current changes.

There is a solution to the above. It is call the *Sziklai/Complementary Pair*. Use a NPN/PNP combo. The schematic looks like this.



Why am I sharing this? Well, this is a circuit block used on many pedals out there and helped me "unlock" one of the schematic secrets out there.
A great example of this would be the PedalPCB _Executive Fuzz_, which is a Jordan Bosstone. I have highlighted the Sziklai pair in the schematic along with a mini-circuit analysis. I plan on writing up a breadboard tutorial soon for anyone who may be interested.



C1 and C4 are the input/output caps. Increase them to allow more bass to come through in this circuit.
R1 and R2 are the voltage divider to bias the complementary pair/unit.
R3 and C2 form a lot pass filter. If you remove C2 the sound gets thinner, but still decent.
C3 helps with oscillation. Best guess here considering the value and where it is located.
D1 and D2 are your hard clipping diodes.
The 2 pots are your pre-gain (think volume knob on your guitar) and output volume.


----------



## bowanderror

BuddytheReow said:


> I've been stalking around Jack Orman's site http://www.muzique.com/ for a while and decided to go through his lab notebook. I chose his Saturation Control page to see how you can change the clipping depth of many circuits that use diode clipping. These are hard clipping circuits, not soft clipping. I would be curious to see how they could be done in, say, an opamp feedback loop but I don't think these ideas here can be transferred part for part. You would be adding resistance to the fb loop and would affect the gain. You can read his article here and all credit for this is to Mr Orman himself.
> 
> What's a simple circuit to try this out on? Why, the MXR Dist + of course! I chose to use the schematic taken from Beavis Audio's beavisboard project found here. If you're wondering how to whip this up on a breadboard it shows how to do that as well. Schematic is posted below. For purposes of this experiment I stopped building after C6. A volume pot is not necessary if I'm just experimenting. Plus, I tend to dime most of my dirt pedal volumes anyway. I also modded the circuit a bit too: change C2 to 100n and C4 to 100n. These 2 mods allow a LOT more bass to get through and gives your tone some balls!
> View attachment 16308
> 
> Jack's article has 9 variations of the saturation control and I chose to experiment out of order than the article reads. I will label them 1 through 9 if anyone wants to follow along with my notebook/blog here. If there is a capacitor in the examples below right at the input I didn't breadboard them since I've already got an electrolytic already in there (C6). It's merely there as a coupling capacitor (I may write up something about capacitors soon).
> 
> First up is example 1. This is the basic saturation control.
> View attachment 16309
> I used 1n4148 diodes since they are the "standard" clipping diode IMO. When turned ccw there should be less resistance going to the diodes from the input signal and it should sound harsher per his article. When I tried this out it was VERY subtle turning the pot in either direction, but it is there. Even tweaking the gain pot of the Dist +didn't change the clipping sound that much. The sound is still very usable though. Oh, I should also mention if you've got the gain pot maxed out there will be clipping BEFORE the saturation control. This clipping happens in the opamp itself.
> 
> I then tried example 2.
> View attachment 16310
> Still using the 1n4148s, this is almost identical to the first example with the exception being that you're controlling only 1 of the diodes. I found this one to be a little less subtle that the first example, but it is still pretty subtle. This one controls the clipping on the negative peaks of your signal.
> 
> Jumping down to the end of the article I went with example 9.
> View attachment 16312
> The pot here is a blend control going back and forth between a pair of hard clipping diodes and your raw guitar signal. The purpose of this is to provide some more subtlety that a simple on/off switch to select the diodes. The pot here would be the equivalent to using hot sauce: sometimes you want a lot and sometimes you only need just a little something. I kind of liked this one and may use it on a future project.
> 
> Working backwards I went to example 8
> View attachment 16313
> This pot is also a blend control between hard clipping diodes and a low pass filter (gets rid of the highs). Since I wanted to hear the full effect of the blend control I modded the Dist + circuit back to schematic stock values (only 2 capacitors and took me all of 30 seconds, if that). It's a very treble oriented circuit so this blend control seemed interesting to try. Lo an behold, it is!! Turning it fully ccw is the full clipping and very harsh sounding and as you dial it to the right you start taking off those nasty, ear piercing highs. Since it's a passive tone filter here there was a bit of volume drop.
> 
> Example 7
> View attachment 16314
> Like the previous example, this one blends clippers and now a _high_ pass filter. To get the most out of this one I remodded the circuit (C2 and C4 to 100n). As you turn the knob to the right you start bringing out the highs in your tone to give it a bit of "sparkle" as said in the article and I agree wholeheartedly. This one is great to put into a DIY circuit IMO. Then again, Jack says this one would be great in a Dist + circuit, so go figure.
> 
> Example 3. Now we go into something called _crossover distortion_ (sounds cool, right?)
> View attachment 16315
> The article suggests to use germaniums or schottkys to get the full effect, so I decided to use BAT41s. Honestly, I couldn't hear anything when going back and forth with the pot. I tried dialing back the gain a lot on the Dist + and couldn't hear anything. I guess I need to try this on a different circuit.
> 
> Example 4.
> View attachment 16316
> A crossover saturation control also attached to a LED (chose a red one). I tend to like the sound of red LEDs as clippers: less compression and more volume. However, I couldn't hear a difference in sound using the saturation knob. I'd like to think I did, but who knows?
> 
> Example 6
> View attachment 16317
> Blending hard clippers and crossover distortion. Despite the volume drop going toward the clipper side, I can honestly say I DO hear the crossover distortion when dimed to the right. It's very subtle, but it's there. To me it almost sounds like the tiniest amount of soft clipping, but not quite.
> 
> Example 5. A simpler variant of the above.
> View attachment 16319
> Altering the behavior of the same pair of clippers to act as either hard clippers or crossover distortion. It sounds very similar to the previous example and am relatively unimpressed. I'd rather use the hard clipper/full signal one instead.
> 
> My thoughts based on the above:
> 
> -I don't get crossover distortion. When I tried to hear it via youtube everyone just points to the oscilloscope showing its occurring and I hear very little change. Maybe because I'm just using my laptop speakers.
> 
> -General saturation controls and to add subtlety, nothing more. If you're a tone snob, and we all are to some degree since tone is subjective, you may want this.
> 
> -My best takeaway from this was the blend controls between the hard clippers and a RC filter of some kind, whether it be a high pass or low pass. These controls are also the most noticeable out of the 9 examples above. Sometimes you only need one tone knob to get a good sound and why not incorporate some clipping in there too.


Nice writeup!

I've also played with some of these AMZ saturation controls, and also found them to be subtle with high Vf diodes (like the 1N4148), especially when fed by a single gain stage.

Because you're adding resistors to the mix, it takes a larger voltage signal to forward bias the diodes and audibly clip them. If you use lower Vf or softer knee diodes, the differences become much more audible. For low Vf & soft knee diodes, Ge diodes (or low gain Ge transistors with collector & base tied together) or diode connected MOSFETs work great. There is a great chart from Repair Cafe that compares the forward voltage & knee characteristic of over 30 diodes. Lots of interesting options:





You're also bound to run into opamp clipping with a single gain stage like the Dist+. I had much better luck with 2 cascaded gain stages, but a rail-to-rail opamp or running the circuit at higher voltage (12-18V) will also give you higher voltage gain before hitting the rails.


----------



## bowanderror

BuddytheReow said:


> Welp, I think I found my limit. I thought my breadboard platform would provide nearly unlimited builds. While this is still true I forgot to figure in user error. My "protoboard" has 3 boards on it and I thought I could work on 3 projects simultaneously. Turns out after 2 things start getting really messy. Especially when I start crossing jumper wires for the various pots. It's always that 3rd build that starts giving me problems.
> 
> Not sure if I should post this here or at the Loafing Lounge thread.
> 
> Here are 2.5 projects before I called it quits: a MuffRat (schematic below and a nice med/high distortion), my L-PB&J Sandwich, and an attempt at Jack Orman's Son of Screamer. I gave up after the gain stage. Now comes the crappy part of taking it all down
> 
> View attachment 15865
> View attachment 15866



I just found this thread and I'm really enjoying it. It's nice to see I'm not the only one who's had a few donnybrooks with a breadboard!

Originally, I also had 3 breadboards hooked together as an all-in-one protoboard, but it ended up being a pretty inefficient use of them, and I'd end up clumsily breaking jumpers off. My solution was to keep them separate and tape them on to clipboards as-needed. To keep the pot & switch jigs in place on the clipboard, I just use some blue tack on the solder side. It's non-conductive & fairly easy to remove when you're done.





The clipboards are easy to store, and the clip portion is helpful for holding things in place:





My recent epiphany was the use of 9mm PCB-mount pots in cut-down female headers. You have to bend the mounting pins to get a good angle for adjusting the pots, but they're easy to bend back into place if you want to solder them to a build later on. I also spent an hour cutting & stripping a TON of different-length jumper wires, which has reduced the amount of "spaghetti" in air over the breadboard. They also do a great job of holding breadboards together:


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## BuddytheReow

bowanderror said:


> I just found this thread and I'm really enjoying it. It's nice to see I'm not the only one who's had a few donnybrooks with a breadboard!
> 
> Originally, I also had 3 breadboards hooked together as an all-in-one protoboard, but it ended up being a pretty inefficient use of them, and I'd end up clumsily breaking jumpers off. My solution was to keep them separate and tape them on to clipboards as-needed. To keep the pot & switch jigs in place on the clipboard, I just use some blue tack on the solder side. It's non-conductive & fairly easy to remove when you're done.
> 
> The clipboards are easy to store, and the clip portion is helpful for holding things in place:
> 
> My recent epiphany was the use of 9mm PCB-mount pots in cut-down female headers. You have to bend the mounting pins to get a good angle for adjusting the pots, but they're easy to bend back into place if you want to solder them to a build later on. I also spent an hour cutting & stripping a TON of different-length jumper wires, which has reduced the amount of "spaghetti" in air over the breadboard. They also do a great job of holding breadboards together:


I've also taken the time to make my own jumper wires out of my solid core 22awg. Not really worth posting here, but definitely worth the time  and effort.

Great idea with the clipboard! I don't need to "clean up" my work area per se, but I just put it aside where the wife won't bother it. Things tend to work itself out.


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## BuddytheReow

I've been pretty busy over the past week or 2 with work and house projects. My last circuit tidbit was about Darlington Transistor pairs. I wanted to see this in action and whipped up a Bazz Fuss found via runoffgroove. It's an incredibly simple circuit composed of nothing more than a transistor, 2 capacitors, a resistor, and a diode. Here's the schematic for it.




Considering the component count this is a pretty decent sounding circuit. Lots of simple substitution mods for this.

What I decided to do with this is to A/B it with the stock circuit as one and the circuit with the Darlington pair in the other via a DPDT switch. Every other component was identical. I chose to use 47n caps for both the in and out just for kicks. Looking at my previous post, you can see that arranging the transistors in that configuration creates one MEGA transistor with gain levels in the 1000s.

My expectations for this were kinda high if I'm being honest. In the first minute or two of comparing the circuits they sounded EXACTLY the same to my ears. WTF? This should sound different with the MEGA transistor in there, right? Stay with me. After a few more minutes (In reality maybe 30 seconds) I realized that the difference sonically occurs when you hold a note or chord. The sustain on this lasts freaking forever! The stock sound dies out like a normal dirt pedal, but this one is ridiculous! With the amount of gain on tap here more signal gets pushed through the transistor and therefore the note decay lasts much longer.

Always nice to see an application of what you might read in a textbook. Btw here's my breadboard with both circuits. I used 2n5088s.


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## BuddytheReow

Hey All,

About a month or two ago I pulled the trigger on a Muffin Fuzz board and it's been sitting on my workbench since. Once I finally got my protoboard up and running (big thanks to @fig ) I decided to start going through all the different variants via PedalPCB's Muffin Fuzz. There are 9 variations out there and there are 2 that I may not do simply due to either not having the correct components on hand (Bigger Muff) or the schematic doesn't mention a few components (Double G Overdrive).

First up is the Martian version. In a separate thread I had a theory question why the input stage had only unity gain on my board. Turns out I had the bjt flipped around. Another point for user error . Anyways, this version definitely has an octave up sound to it and reminds me of the hyped fuzz board I built a year ago or the ionizer. You can definitely get some Electric Wizard type sounds out of this one! I really like it with a downtuned guitar on it. Will this one be the winner for my board? Honestly, probably not since I have others that sound similar to this one.

Since I have the layout figured out from schematic to breadboard the other versions will come together much quicker.


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## fig

I have some catching up to do here! I just read through your darlington pairs write-up and re-post, a fantastic read for someone wanting to better understand a LOT of popular circuits. Your illustration should light up more than a few lightbulbs! (it lit _my_ fire) Thanks 👍


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## Chuck D. Bones

Very clean layout!


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## Chuck D. Bones

At first glance, I thought this said "TWAT."


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## BuddytheReow

Chuck D. Bones said:


> Very clean layout!


Thanks. Making my own jumpers makes the picture look better. That and I really don’t like using the prepackaged ones unless I have to. They tend to be either way too long or short


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## Chuck D. Bones

I make my own jumpers too. but I'm not quite A/R enough to make them exactly the right length or run them along the grid lines.  And that explains why I have parts and jumpers in the wrong place sometimes.


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## bowanderror

Chuck D. Bones said:


> At first glance, I thought this said "TWAT."
> 
> View attachment 19128


Sometimes my internal monologue gets externalized.


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## BuddytheReow

Been a while since I posted here, but I have some flexibility this week in between holidays to work on some breadboarding. Last week Dirtboxlayouts posted a handful of Devi Ever circuits. Devi's circuits are relatively simple for the desired effect. This is an overdrive circuit called *Devi Ever Electric Brown*. https://dirtboxlayouts.blogspot.com/2021/12/devi-ever-electric-brown.html 

A skill that I wanted to work on was to convert a layout (stripboard, p2p, pcb, etc.) to a schematic and then breadboard it. It didn't take too long to figure out, but what stumped me for a while was the purpose of the second transistor. I'm not cheating here, but below is the schematic I found that matches what I did (my handwriting ain't the best). See the top schematic. I _think_ it's purpose is to act as a diode since the emitter is not used at all. *Can anyone chime in with their analysis/purpose of the second MPSA18?* I added a switch to compare the sound at one transistor vs both and it's subtle, but it's there. Pardon the messy layout since I'm usually pretty anal about that stuff, but I said screw it this time.

Anyway, this is an ok transistor based overdrive. You need to dial in the pre-gain pot to remove some of the gating. If you've got the parts laying around this is definitely one to try.


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## Chuck D. Bones

To say that Devi Ever's circuits are unconventional is a gross understatement.  Makes it very difficult to sanity-check the traces and Vero layouts.  How did you switch the 2nd transistor in/out?  A series switch that creates an open circuit or a parallel switch that shorts B to C?  I think a regular Silicon diode would work in place of Q2.  Whatever that 2nd transistor does, it must only do it during the note attack.  That 100nF cap blocks DC and the transistors C-B junction only lets current flow one way.  OK, there's a tiny reverse leakage current.  The C-B diode might turn on briefly
during the attack of a note or chord.   IDK.


----------



## BuddytheReow

Chuck D. Bones said:


> To say that Devi Ever's circuits are unconventional is a gross understatement.  Makes it very difficult to sanity-check the traces and Vero layouts.  How did you switch the 2nd transistor in/out?  A series switch that creates an open circuit or a parallel switch that shorts B to C?  I think a regular Silicon diode would work in place of Q2.  Whatever that 2nd transistor does, it must only do it during the note attack.  That 100nF cap blocks DC and the transistors C-B junction only lets current flow one way.  OK, there's a tiny reverse leakage current.  The C-B diode might turn on briefly
> during the attack of a note or chord.   IDK.


The switch is where the volume pot should be. The bottom cap I put right after the collector of q1 (one end of the switch is here) and I also added a jumper wire from that to where the volume pot would be. Both caps meet there and that’s my other switch point. The middle lug of the switch is output.


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## BuddytheReow

I decided to whip out a TL074 and build something with it. The 074 uses 4 opamps in a single chip. The plus side of this is you only have to power the chip once rather than using 2 separate TL072 or 4558s. This isn't really a new circuit or anything, but rather 2 circuits in one using the same IC. I chose the *Mini-Muffin Fuzz and Cold Turkey EQ* circuits. The Mini Muffin really needs a tone stack or tone control so I decided to try this one out. For both circuits I took out the volume pots since I'm merely testing the circuits.

My opinion is that this concoction is ok, not great. The fuzz portion is relatively bland and needs a fuzz control on it for both an increase and decrease, but the EQ helps color the sound more to my liking. I did add a 1m pot in lieu of R3 to make it louder, but it did not help much. When I max out the TREBLE pot I get some unwanted hiss, so I'm not sure If that's due to my breadboard, the IC used, or the circuit iself. @Chuck D. Bones helped me with the analysis of the EQ stage since I noticed that changing the MIDS pot kinda took over the other two settings in addition to trying to figure out why the schematic is drawn the way it is. His suggestion was to put the MIDS control in it's own separate opamp stage to make it truly independent of the other controls. Thanks for the tip, Chuck!

Again, not an original design by any means but I will call this one the *Turkey Muffin.*


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## Chuck D. Bones

Stick a resistor in series with C5, that will help with the MID control overriding the other two.  Try 4.7K, 6.8K or 10K.

If you really want a 3-band EQ, try copying the EQ section from the Crunch Captain Deluxe.  [Or just build the whole thing]


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## Coda

Not as detailed as some, but I threw this together this afternoon: Elka Dizzy Tone. I have a GPCB Buzzaround board that I plan on using for a full version. Much more gnarly Buzzaround. Npn Ge…don’t remember what. HFEs are around 50/50/110…


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## BuddytheReow

Future Buddy, this is Past Buddy. You've tried breadboarding a simple non-inverting opamp for some time and can't seem to get the circuit to work. You've check over the layout and schematic and see nothing wrong. Your IC voltages seem off even though it's powered correctly. You are telling yourself this is some pretty basic &$#^ that you used to be able to do without any issues when you first started breadboarding.

Future Buddy, pay attention. This is so simple since you used to be able to do this in your sleep. I will refer you to a troubleshooting post you opened up. https://forum.pedalpcb.com/threads/a-breadboarder-needs-help-dist-250.10283/

If you decided not to read it then I will give you a hint of how to tackle this. Refer to a previous project you posted many months ago in this thread. Look at the way the breadboard is laid out, specifically with the feedback loop. Don't switch around the input and output jumpers: the rc filter gets connected to the - input of the opamp, not the output. That's why you're having issues.

You're welcome future Buddy.


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## Barry

Chuck D. Bones said:


> Stick a resistor in series with C5, that will help with the MID control overriding the other two.  Try 4.7K, 6.8K or 10K.
> 
> If you really want a 3-band EQ, try copying the EQ section from the Crunch Captain Deluxe.  [Or just build the whole thing]


Crunch Captain Deluxe is one of my favorites


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## BuddytheReow

I did some experimenting with biasing a transistor and wanted to share my findings here for anyone who's interested. Here's the schematic for my base:


 
The resistors here don't have values because that was the experiment I tried. Emitter to ground, a shunt feedback resistor from collector to base, and a collector resistor. Everyone, this is a simple fuzz circuit. Now what I did was wire up two 1M potentiometers to act as variable resistors here. As I played through this simple circuit I tweaked the resistors to see what that would do to the sound. Here's what I found. I used a 2n5088 as my starting point.

Rc=1m Rcb=1m, a very heavy overdrive sound with some gating thrown in there. Keep in mind I only have humbuckers in my guitars. As Rcb decreases the sound gets more "pinched" for lack of a better term and volume does decrease, although the signal is still hitting the power rails. I noticed the signal dies at around 15k or so. Turn Rcb back to max and tried the other pot. As the resistance decreases all I noticed was that the gating only gets slightly less until the signal gets choked out. THe signal cutoff I found was around 8k.

Let's try the pots at their lowest settings possible. For my setup, Rc~2.8k and Rcb~14.8k. The sound produced here was actually pretty clean and the treble comes though very well. It is not a clean booster but a more treble-y booster of sorts. As I increased Rc, more "gain" like in a guitar pedal setting comes through more and the bass also comes back into play. Now we're back into heavy OD/fuzz territory! OK, reset back to the lowest settings for each. As I increased Rcb, "gain" comes back, but there is a quick volume drop and slowly comes back as it's increased further. The gating starts coming back right after noon.

Having both pots at noon gives a lot of harmonics come through more.

When I change to different transistors I noticed that if the hFE is lower for the transistor, there is a lot more gating happening at the settings mentioned above. The opposite is true for higher hFE transistors and seems to be more forgiving.

Some other comments/notes:
-Running the circuit at 18v gives a lot more headroom and allows the signal to not hit the power rails as hard although the clipping is unaffected. This is a great way for me to understand headroom and running circuits and different voltages.
-The most "tweakability" range for me was when the resistors had relatively low values (<100k). Perhaps I should try this experiment again but use 100k pots.
-The lower the values of the resistors the closer to an overdrive it sounded.


Future Buddy, try this experiment again using 100k pots. Also try other topologies to see what you can come up with.


----------



## Chuck D. Bones

When you turn those pots, you're changing the signal path _and _the transistor's bias at the same time. There are a LOT of settings where the transistor is either saturated or cut-off when no signal is present.  When you hit the circuit with some guitar signal, then the transistor gets pulled out of saturation or cut-off until the note decays to the point that it can't overcome the transistor's extreme bias.  Voilà!  Gating.  When you find a setting you like, take note of the collector voltage.  This biasing scheme is VERY HFE dependent.  Two transistors with the same part number may well sound different.


----------



## BuddytheReow

Feral Feline said:


> Also check out ESP for "Designing With Opamps" Parts 1 & 2  by Rod Elliott.


Dude, I completely missed this when you posted it. There's a lot of good reading material. I'll take a look through it tonight and throw it into the resources thread in the Test Kitchen


----------



## BuddytheReow

More experiments this afternoon and here are my findings for those that are interested in circuit design. I decided to put together a different configuration of getting a transistor to conduct. This is pretty much a common emitter amplifier with tweakable resistors. You can find this configuration on an LPB-1 minus the pulldown resistor. It's considered more stable and you'll see why in a minute. You can also call this a voltage divider bias (I'm looking at Electronics-Tutorials site for the names). Here's the schematic I put on my breadboard. I'm labelling the base resistor B, the collector resistor C, and the emitter resistor E (duh)...I used a 2n3904 here and at the last minute switched to a 2n5089.



Why a 9.1k resistor to ground? Well, using a simple voltage divider calculator, I found out that having B at 100k and Rb at 9.1k will give me nearly the lowest voltage to turn on the transistor. Basically, I would play and turn the knobs until I got sound and saw how much the sound changed.

Here's the short version of what I found and doing next to no math (sorry, Chuck):

-This configuration is more stable than using the collector resistor feedback method I did previously. When I say "stable" I mean that the sound that comes out the other end is between clean and a light to medium overdrive. That's it. This configuration is really meant for amplification rather than clipping and it makes sense that the LPB1 is laid out this way. It's a simple amplifier.

-B pretty much needs to stay maxed out (100k) in order for anything to work. As E is increased you get slightly more wiggle room but not much. The signal sound gets "starved" really quickly.

-As E increases, the value of C needs to increase in order for signal to pass through. You also get more wiggle room in terms of min and max resistance for sound to pass through

-There's clearly a difference in the amount of clipping/amplification when going between single coil and humbucker pickups. Humbuckers drive this harder obviously.

-Using a higher hFE transistor (I used a 2n5089) I get much more wiggle room for turning the collector knob. Other than that, not much different sonically.

BTW I did write down resistance values when signal pass through or not, but the above pretty much sums it up here. Again, this is a super simple, basic topology where I'm trying to answer the question "Why is this circuit built like this? What does it do?" Now I know.

BuddytheReow

Edit: If you look at some common emitter amplifiers out there you'll notice a cap also going from emitter to ground. This will increase the amplification and some of the gain. I noticed diminishing returns after about 10uf or 22uf. This seems to be the sweet spot in my given circuit.


----------



## BuddytheReow

Whipped up a Baxandall Tone stack on stripboard today for circuit design. Another one to add to the collection. Found it on http://guitar-fx-layouts.238.s1.nabble.com/Bax-in-a-box-active-baxandall-tonestack-td7264.html

Not the neatest layout, but for it's purpose it works just fine. This can be a standalone "effect" and put in an enclosure if you choose. This layout works.

Now it's time to create something!


----------



## BuddytheReow

I took a little bit of time over the weekend to explore the famed pt2399 chip. This chip is used in many delay pedals, and maybe a chorus or reverb pedal if tweaked correctly. Before understanding the chip itself I was looking for the most simple circuit to breadboard and found this. Keep reading below.




So, first of all, this circuit works, but not the way I wanted it to work. It acts more as a reverb than a delay. Because this circuit worked when I breadboarded it I wanted to see how this unusual chip actually works and perhaps start designing my own. Here are some great resources I found that helped me understand it.

I hate to put this up here since I really can't read datasheets to the fullest extent I am putting it up here. Why? Well, in the handful of google searches I found useful they reference the datasheet since it also has 2 pretty good applications of this circuit that can almost be directly applied to guitar effects. These are the 2 topologies that are the backbone of many delay circuits.



			https://diyaudiocircuits.com/wp-content/uploads/2012/09/2399.pdf
		


Of course, one of the first search results that popped up under "pt2399 analysis" is the one done by electrosmash. I think it's pretty good, but some of the things talked about kinda went over my head since I'm not an EE but I do have a good base understanding of electronics. This helped clear up some of the things about the chip itself (what does pin 6 do?, etc)





						ElectroSmash - PT2399 Analysis
					

Circuit analysis of the PT2399, a CMOS echo/delay/reverb processor by Princeton Technology.




					www.electrosmash.com
				




Here's another good high level analysis of the chip and it's applications. Mods are discussed with some other links in here about what others have done with this chip.








						PT2399 Digital Delay IC - DIY Audio Circuits
					

The PT2399 is one of the most rewarding chips a DIYer can experiment with.  A stock circuit from the datasheet can nearly complete a guitar pedal project, and there are …



					diyaudiocircuits.com
				




To really help solidify my basic understanding of the chip is to see it in action in a working circuit. This video really helped me understand a basic delay circuit with the common controls (level, repeats, time) that can be found in others. There is no LFO here (I still can't seem to breadboard a working one yet ) which helps to simplify things. This guy goes through the schematic nearly piece by piece and says "hey, this resistor is placed here because it does..." which is really helpful for a regular dude like me.









Anyways, looking at the most common mod (pin 6 controls the delay time) I decided to put a 100k pot (most circuits have 50k) to fool around and see what sounds I could make with it. The longer the delay time the more distorted the signal gets and the more noise comes through. I still kept the original circuit on my breadboard with just that one mod. It works with the mod, but needs tweaking since the two pots don't interact very well. It can squeal like a piggy...

I think the next step would be to whip up a PPCB circuit and start fooling around with it, but I think the 90 minutes I spent breadboarding the "basic" circuit and going through analyses were fruitful.


----------



## BuddytheReow

I found this the other day while browsing around the net. This is a collection of Devi Ever circuits, their various topologies, and stripboard layouts for them. There are 7 topologies in here with variations of them to arrive at the various pedals done over the years. The circuits themselves seem pretty basic and are definitely worth breadboarding at least to tweak them to you taste. Since I do not own any Devi pedals I cannot trace them to confirm whether or not they are accurate in the file.

A few things I noticed:

-The circuits themselves are pretty simple as mentioned above.
-Some of the circuits I have no idea why they are laid out like that. The LP and Electric Brown for example
-Devi likes to use very similar value components in the various builds. 100nf caps, 2.2m and 3.3m resistors, and MPSA18 transistors. It would be worth stocking up on these to try em out. You can get everything on Tayda since they are all pretty basic components









						devi-ever-diy-info-manual-aw-heck-yes.pdf
					






					drive.google.com


----------



## fig

I also enjoy building datasheet examples. The 2399 was actually one of the first I ever did, or tried. I can't remember if it worked or not...no matter, I learned through it...and I'm still learning. Your write-ups are great! Thank you for taking the time to put them together. They really are appreciated.


----------



## BuddytheReow

It's been a while since I've posted something here. 4 months, really? Huh. I guess i've been too busy with work and house projects to get some experiments done.

Anyways, I recently posted a breadboard tutorial how to build a RAT. You can find it here if you're interested.





						TUTORIAL - Muroidea - Proco Rat
					

Ah, the Proco Rat. Built in the 1970's and popularized in the 1980's, it can be considered a "standard" in the distortion community. This little baby can do it all: pseudo-overdrive or light distortion, distortion, and borderline fuzz territory. Due to its simplistic circuitry and versatility it...




					forum.pedalpcb.com
				




I'm about to embark on modding this fantabulous circuit and I realized that I have a good comparison of all the different RAT pedals out there. In case anyone is interested here it is. I don't remember who sent this to me so if you're that person, thank you!

I gotta come clean. I also wanted a reason to bump this thread for any new members who are curious about circuits and how they work. Once again, the RAT saves the day!


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## BuddytheReow

I had some time today (time? What’s that?) to myself and I wanted to see what the Mach 1 Overdrive was all about since I’ve seen a handful of them in the Build Reports recently. People here claim it’s a pretty “transparent” overdrive so I cleaned up my rat and put it on there. This is more of a preview of the next breadboard tutorial. I see the appeal of overdrive circuits, but it’s not really my style of playing (although I tend to play a sweet blues riff with some overdrives). I will, however, stack it before another dirt pedal to get a different sound that I tend to like when I do use overdrives. Anyways, here’s my Mach 1. Coming soon to a “New Posts” near you!


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## BuddytheReow

Chuck and I are working up something for budding circuit designers, so I thought I would document what I did here. We're working on an output booster circuit block. So, I made a quick dirt pedal with Chuck's help. The GAIN control goes from little to no gain all the way to a searing fuzz/distortion. 2M may be a bit high for the value since they are not super common, but 1M would work just fine. The output booster is really loud and in hindsight I think maybe a volume pot is not necessary? Anyways, here is how it's laid out:

FUZZ>Hard Clippers>BMP Tone Stack>Output Booster>Volume knob

I call it the "Wish Not Buzz Not"


----------



## Chuck D. Bones

Try putting the VOL pot between the tone stack and the output booster.  A100K.  Replace the BOOST pot with 100Ω.

I'll breadboard this puppy and see if there are any other potential mods.


----------



## fig

Those MOSFETs are powerful critters.


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## BuddytheReow

Chuck D. Bones said:


> Try putting the VOL pot between the tone stack and the output booster.  A100K.  Replace the BOOST pot with 100Ω.
> 
> I'll breadboard this puppy and see if there are any other potential mods.


What's the reason for changing the VOL pot to 100k if moved? How does it interact with the rest of the circuit?


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## Chuck D. Bones

The BMP tone stack was originally designed to drive a load around 80K.  Play with the value of R4 in TSC and see what it does.  We can design a BMP tone stack to drive just about any load, and it need to be tuned to the load to get the best sweep.  I find good results when the TONE pot and load are the same value. 

While we're talking about loading, what kind of load does the MOSFET booster present to the tone stack in the above schematic?

Any guesses?


----------



## BuddytheReow

Chuck D. Bones said:


> The BMP tone stack was originally designed to drive a load around 80K.  Play with the value of R4 in TSC and see what it does.  We can design a BMP tone stack to drive just about any load, and it need to be tuned to the load to get the best sweep.  I find good results when the TONE pot and load are the same value.
> 
> While we're talking about loading, what kind of load does the MOSFET booster present to the tone stack in the above schematic?
> 
> Any guesses?


I’m gonna guess 3.3m?


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## Chuck D. Bones

BuddytheReow said:


> I’m gonna guess 3.3m?


BZZZZZZZZZZ!

Wrong answer, thanks for playing.

Anyone else?


----------



## fig

Does it depend on the control setting?


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## Chuck D. Bones

Mmmmmmaaaaaybeeeeee.  To which control are you referring?


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## fig

The one that changes the load to the tone stack. 😁

The VOLUME control sir.


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## Chuck D. Bones

The volume control is after the MOSFET in the schematic above, so...

BZZZZZZ

Thanks for playing.


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## fig

It’s quite a boost with just that bit.


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## Robert

It's basically a SHO at this point, right?


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## fig

Minus the U1-GS 1N4148?


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## Robert

Yep.   I don't think the early SHO's had the protection diode.


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## Robert

If you like that circuit you should check out the Modus Operandi schematic and tack on that 2N2222A stage.

Maybe it's placebo (I never A/B'd them)  but it seemed to add a little something.   I could leave that pedal on all the time.

https://docs.pedalpcb.com/project/ModusOperandi-PedalPCB.pdf


----------



## Betty Wont

Robert said:


> Yep.   I don't think the early SHO's had the protection diode.


That's correct. Early SHO's had an extra bs170 taped to the inside lid for blowouts.


----------



## Chuck D. Bones

Robert said:


> If you like that circuit you should check out the Modus Operandi schematic and tack on that 2N2222A stage.
> 
> Maybe it's placebo (I never A/B'd them)  but it seemed to add a little something.   I could leave that pedal on all the time.


I'd say that hanging Q2 there is a bit silly.  Q1 can drive that 2-pole low-pass filter no problem.  If one wanted to be clever, then Q2 could be configured as an active 2-pole low-pass and DC-coupled to Q1 since Q1-D and Q2-B are essentially the same voltage anyway.


----------



## Robert

Chuck D. Bones said:


> I'd say that hanging Q2 there is a bit silly.



No, it was taped to the lid, I don't think they called it Q2.     

Seriously though,   you know I don't analyze these things.    

If I go around "improving" things folks will raise hell.   I leave the mods and upgrades to you guys.


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## fig

I did this..it’s a 2N4393 with a couple of clipping diodes…not 100% on the clipping level control, but still pretty cool.


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## Chuck D. Bones

Schematic please.


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## fig

It's the final two stages of the Voodoo Woman, with a 2N4393 tacked onto the OUT, and a 680Ω resistor to DRAIN, SOURCE to GND. DRAIN is OUT.

The clipping bit didn't actually _do_ anything audibly.


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## Chuck D. Bones

That JFET is running on the edge of saturation.  Id is idling at Idss.


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## Chuck D. Bones

Yeah, you really need a source resistor to get the biasing right.  Or maybe it's doing exactly what you want, in which case forget what I just said.


----------



## fig

As cool as _"running on the edge of saturation"_ sounds (and it sounds awfully cool....I may use it in some lyrics...royalties?)...I think I'll get myself one of them "source resistors" and run with the pack...thank you sirs!


----------



## Chuck D. Bones

If you want to maximize gain, then bypass the source resistor.  I usually pick a drain resistor and then dial-in the source resistor to get the desired drain voltage.  For maximum headroom, the drain voltage should be 1/2-way between the source voltage & Vcc.  It's counter-intuitive, but for a given Vcc, FETs will produce more gain with lower drain current.  There are diminishing returns so I wouldn't run the drain current much below 100μA.

Here's what I did with Sandy's example circuit.  The clipping diodes are Germanium.  At low FUZZ levels, the clipping is symmetric with just a few odd-order harmonics.  At higher FUZZ levels, the clipping becomes increasingly asymmetric because Q1 drives the diodes asymmetrically.  Q2 runs clean with LEVEL below noon.  At higher LEVEL settings, Q2 adds some even-order harmonics.  If you want Q2 to run dirty all of the time, then swap VR3 & R9.  Any JFET will work, just tweak the source resistor.  As usual, all component values are negotiable.


----------



## BuddytheReow

So, yesterday I put together in the resources section a handful of Devi Ever snippets that she uses in a lot of her fuzz pedals. For Devi, it's usually a mix-and-match type of situation and slap a new name on the circuit. As a due diligence process for myself before posting anything I have to try them out for myself. Here's my _Devi Breadboard_ project for mix and match. The top left is a pre-gain or fuzz section, top right is a volume pot/output section, bottom left is high and low pass control that I cooked up. There are 4 Devi snippets in the middle that I wanted to mix and match to see how everything reacts together, link them to the filters and then output. I'll be sharing my Devi Baby shortly...


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## BuddytheReow

Taking a few pages from the Devi Ever playbook I hooked up a few blocks together and really liked it, but didn't love it. If you keep the circuits as is they can get waaaay too bass heavy and muddled depending on how the circuit flows. To counter this I tweaked both a variable high pass and low pass filter for some decent variability in tone. The one circuit block that really caught my eye/ear was the block with a 2n2222a acting as a diode in the feedback loop. It's more of a clipping circuit than anything else, but it also takes out a bunch of muddy bass.

After mixing the circuit blocks with some slight tweaking (I added C2 below) and tone controls I found something I'm actually _really_ happy with. I love this circuit so much through my amp that this will be going on top of my list in an attempt to put it on vero and box it up, though it may need a slight tweak or two to make it shine. For starters I may need to tweak the BASS control since it gets too treble-y when turned CCW, but that's a simple fix.

I'm hesitant to fully call this a fuzz pedal since you can dial back the FUZZ control and it sounds like a pretty good distortion pedal IMO. Max out the FUZZ control and some gnarly fuzz tones are at your fingertips. SO yea, it's a _FUZZTORTION_ pedal.

I call this one the *HEAVY DEVI*_. _I hope some of you will try this out on a breadboard.


----------



## BuddytheReow

Chuck D. Bones said:


> If you want to maximize gain, then bypass the source resistor.  I usually pick a drain resistor and then dial-in the source resistor to get the desired drain voltage.  For maximum headroom, the drain voltage should be 1/2-way between the source voltage & Vcc.  It's counter-intuitive, but for a given Vcc, FETs will produce more gain with lower drain current.  There are diminishing returns so I wouldn't run the drain current much below 100μA.
> 
> Here's what I did with Sandy's example circuit.  The clipping diodes are Germanium.  At low FUZZ levels, the clipping is symmetric with just a few odd-order harmonics.  At higher FUZZ levels, the clipping becomes increasingly asymmetric because Q1 drives the diodes asymmetrically.  Q2 runs clean with LEVEL below noon.  At higher LEVEL settings, Q2 adds some even-order harmonics.  If you want Q2 to run dirty all of the time, then swap VR3 & R9.  Any JFET will work, just tweak the source resistor.  As usual, all component values are negotiable.
> 
> View attachment 27999


Chuck, why do we need R10 in your schematic since it's so low?


----------



## Chuck D. Bones

BuddytheReow said:


> Chuck, why do we need R10 in your schematic since it's so low?


We don't absolutely need it, but it provides some filtering of the external power and ensures that the current step from switching the LED on & off will not couple into the audio signal.  I put R10 in because I could.  The current demand is low and the voltage drop in R10 is about 300mV.  The circuit works fine with no resistor there.


----------



## BuddytheReow

Tweaked the low pass filer a touch. THis is much better when turned fully CCW.


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## Chuck D. Bones

Maybe try 4.7K for R5 so you don't lose so much volume when BASS is dialed back.  Does R4 do anything?


----------



## BuddytheReow

Sigh...R4 does nothing. The 2n2222a does all the biasing. I'll keep it in there for the true Devi spirit.

Changing R5 starts some weird oscillation. I'm keeping it at 10k.

I added a 10k in series with R6 to the pot and the volume stays when dialed back. I'll update the schematic tomorrow


----------



## Chuck D. Bones

That oscillation should not happen.  It is an indication of an underlying problem.  Do you have a 100uF power supply bypass cap?


----------



## BuddytheReow

Chuck D. Bones said:


> That oscillation should not happen.  It is an indication of an underlying problem.  Do you have a 100uF power supply bypass cap?


I do. Should I increase or decrease the capacitance?


----------



## Chuck D. Bones

Neither.  I don't see how power & ground are connected between the top & bottom proto-boards.


----------



## BuddytheReow

Chuck D. Bones said:


> Neither.  I don't see how power & ground are connected between the top & bottom proto-boards.


The two boards are not connected. I probably should try that with the filter cap thrown in there. I remember having an issue with my boards a few months ago and grounding everything to everything else pretty much fixed the issue. Not sure why this is creeping back up now.


----------



## Chuck D. Bones

Are you carrying signal from one board to the other?  Hard to follow what's going on, your breadboards are starting to resemble mine.


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## BuddytheReow

I'll cleanup my boards of the unused circuit blocks and share them here. The short answer is yes.


----------



## Chuck D. Bones

If you carry signal from one board to another, then you need to also carry power & ground from one board to another.  Those power and ground connections need to be short & sweet.  Doesn't hurt to put 100uF power supply bypass caps on each pair of rails.


----------



## BuddytheReow

I only had a short amount of time tonight. Wasn’t sure whether to paint a pedal or clean up my board. I chose both 😀.

Now the sound is very different and the treble control doesn’t work. I’ll troubleshoot it in the morning. The oscillation is gone.


----------



## Chuck D. Bones

One step forward, two steps back...


----------



## BuddytheReow

Fixed. I had the second stage going from base to the output cap instead of collector to out. The treble pot wasn’t working but I just wired it incorrectly.

In terms of the oscillation it’s gone, but a long-standing problem with by board has come back. For some reason I have to power each rail separately (ground and +). I’m thinking this may be a problem with the board itself and not the circuit?


----------



## Chuck D. Bones

All power rails (of the same voltage) used to power a part of the circuit must be connected together and to the source.  Same goes for ground.

Here's an example.  I breadboarded a modd'ed Klon.  All blue rails are ground and they're all jumpered to each other.  Top red rail is -9V.  Next red rail down in +18V on the left half and Vref on the right half.  Next red rail down is +9V.  Bottom red rail is unused.  The power jack connects to the +9V rail and one of the ground rails.  The charge pump circuit connects to the -9V, +9V and +18V rails.


----------



## BuddytheReow

Here's the updated schematic. I'm going to make an attempt to put this on vero. I fooled around with DIY Layout Creator on my lunch break today and need to fire up the iron. I'll circle back here once my layout is confirmed.


----------



## Feral Feline

Diggin' the Bredi Deverboard, Buddy!


----------



## BuddytheReow

A day or two ago I began the journey of how to put my Heavy Devi schematic onto vero and I used DIY layout creator. It's free (me likey   ) and pretty user friendly. If your just starting out on this program, I would suggest drawing a very simple layout such as a LPB-1 or a BMP tone control just so you can understand how the program works, although it is pretty intuitive. I remember attempting the program almost a year ago (it's in a thread here somewhere) and had similar results. It took me probably a good hour to draw this out from the schematic. Some advice: check and recheck your work here tracing the circuit, both AC and DC paths. Do the work here so your soldering time becomes fun. The layout had to get tweaked slightly after my first go around thanks to our local circuit wizard Mr @Chuck D. Bones and his guidance.

Behold! The *Heavy Devi*! This is a gnarly little fuzz circuit inspired by Devi Ever's common circuit blocks. There are 4 controls: VOLUME, FUZZ, BASS, and TREBLE. BASS and TREBLE cut out the corresponding frequencies. This circuit is relatively bass heavy, but not as muddy as you may think. VOLUME is pretty self explanatory and doesn't really affect much else in the circuit.

The FUZZ control is where the fun is at. CCW and you're in distortion sounding territory. I say that because of the treble attack that comes through reminds me of a decent distortion pedal without the ice pick highs but still relatively tight sounding. You can dial back your guitar's volume a lot and get a very "pinched" sounding fuzz too. As you start to crank it more and more gnarly fuzz comes through known in many of Devi's circuits (think Hyperion here). When maxed out there's some noise that comes through, but that's ok considering the overall tone.

To be perfectly honest with you guys, this is a big milestone for me. If you've been with me since the beginning of this thread then you know my "goal" was to design my own circuit start to finish. Is this circuit 100% original? Hell no since it's merely putting existing building blocks together in a way that I like. Can I call this circuit my own? Absolutely! There is no other circuit out there that I know of on the interwebs that contains this particular layout and component values. Although this is a pretty simple circuit, I had tons of fun doing this little experiment that I quickly fell in love with.

I'm posting my experience here to hopefully inspire others to do the same. Experiment; try something new; do a little reading on how/why a circuit block works the way it does and then try it and see to reinforce the learning.

Oh, yea. This layout is verified . With 4 pots, this won't fit in a 1590A. 1590b probably and definitely in a 125b given the size of the board, though you'll have a lot of empty real estate inside. The pots are wired here as if the knobs are facing up. These layouts can get confusing sometimes. The power filtering cap was a bit of an afterthought since the protoboard already does that and apologies for the diagonal placement here. Can't you tell I'm excited about this? I hope some of you try this circuit out.

-BuddytheReow


----------



## Feral Feline

Awesome work, Buddy!


----------



## fig

You know I’m building this  Thank you!

It may be good practice to include the power section in the schematic, for newer builders of these wonderful things!


----------



## BuddytheReow

Finally boxed up this afternoon. I have a few ideas for the enclosure art.


----------



## BuddytheReow

I did 2 quick writeups on a blended fuzz and an input section. Why not combine both in one circuit?

This is my latest little ditty I came up with. The FAT control alters the amount of bass into the circuit. C3 gets rid of RF and some of the highs. The BLEND control is unique here in that when set at about noon you get some weird harmonics coming through. I had to tame the 2nd stage volume which is why I put R4 in there. Switchable hard clipping diodes afterwards cuz, why not? Simple volume control afterwards.

I call this circuit the *2 End Blend*. Let me know what you think on your breadboards.

BuddytheReow


----------



## Chuck D. Bones

Kinda resembles a Fuzzrite.  Since you're blending out-of-phase signals, you should get some octave-up tones.


----------



## BuddytheReow

Chuck D. Bones said:


> Kinda resembles a Fuzzrite.  Since you're blending out-of-phase signals, you should get some octave-up tones.


Yea. It has a similar topology with some extra goodies thrown in there. I'm sure with your knowledge you can make this better. It was a fun build regardless.

@Chuck D. Bones how can you tell just by looking at the schematic that the signals would be out of phase? What's the giveaway here?


----------



## BuddytheReow

I took out the hard clipping diodes and added a blendable Squidward after the BLEND control. A blendable fuzz into a blendable Squidward then to volume. Why? Well, why the heck not!


----------



## Feral Feline

BuddytheReow said:


> Yea. It has a similar topology with some extra goodies thrown in there. I'm sure with your knowledge you can make this better. It was a fun build regardless.
> 
> @Chuck D. Bones how can you tell just by looking at the schematic that the signals would be out of phase? What's the giveaway here?



For my own edification I will try to reason this out. The first transistor flips the phase, then you split the signal into A & B.
A goes through another transistor flipping the phase of A again, so it's in phase with the original dry signal, but B is still flipped out of phase.

Add a transistor buffer/boost to B that flips B's phase before you mix A and B back together and you should be okay.


----------



## BuddytheReow

Feral Feline said:


> For my own edification I will try to reason this out. The first transistor flips the phase, then you split the signal into A & B.
> A goes through another transistor flipping the phase of A again, so it's in phase with the original dry signal, but B is still flipped out of phase.
> 
> Add a transistor buffer/boost to B that flips B's phase before you mix A and B back together and you should be okay.


That makes sense to me


----------



## BuddytheReow

I attempted to make a vero layout of the *2 End Blend Fuzz*. I haven't gotten around to soldering it, so this layout is right now not verified but it looks ok to me. If this doesn't work let me know. Work has been crap this week so I don't have the time to test it right now. Sorry for the diagonal layout of that ONE resistor but it made the board a bit smaller. I'm still practicing my layout abilities here. It's like a puzzle.


----------



## Feral Feline

Much better having simple labels, those backwards pots in the first vero version threw me for a loop as I started to work up a perf version...


----------



## BuddytheReow

I whipped up the 2 End Blend Fuzz over the weekend and there was a small change to the layout. This one is verified   .

Will this get boxed up? I'm not sure yet. I've got other projects I'm working on. Alter the clipping diodes to your taste (D2, D3).


----------



## zgrav

BuddytheReow said:


> That makes sense to me


maybe have the extra transistor as a switch-in or switch out to have the option of blending two out of phase signals.

The building blocks for breadboarding are going to be a lasting resource here for a lot of people -- thanks for sharing!


----------



## BuddytheReow

More a PSA than anything else to the aspiring breadboard baker, jumper wires make a huge difference. The problem is that a lot of the more flexible wires are either way too long or way too short and can make your layouts quite messy. So, naturally, I started making my own jumpers out of some hookup wire in various sizes and color coordinated. This turned out to be a very tedious and time consuming process and I think I made 1-2 dozen in about an hour by more or less eyeballing the different sizes I needed. A few days ago I bit the bullet and dropped $12 for some hookup wire based jumpers and these are a godsend! Sometimes I'm waaaay too cheap in this hobby thinking I can just DIY everything. $12 saves me hours of tedious work with no circuit built as a result. The small ones in the bottom right corner will be used all the time based on how I layout my boards. The large ones I'm probably not going to use, but you never know.

I still need to pull the trigger on some breadboard mountable switches which will clean up the layouts even more.



			https://www.amazon.com/dp/B07CJYSL2T?psc=1&ref=ppx_yo2ov_dt_b_product_details


----------



## BuddytheReow

Using my new jumper wires I decided to go back to basics a little bit and use the good ol’ Bazz Fuss as the dirt portion. For anyone interested in breadboarding, get yourself a pack of these jumpers and some tweezers. This is a blended input cap into a Muff style input stage into a homemade darlington Bazz Fuss with a bias control (1n4148 diode for now but may make that switchable) into a baxandall tone stack taken directly from the Acid Rain Fuzz followed by a volume control . The input muff stage has a very large resistor (220k I think) going to ground at the output and acts as a “starve” control.

5 knobs, 4 BC549Cs, and a diode. I call this one the *Thunder Fuss*. Schematic and attempted vero layout will follow for those that are interested.


----------



## Bricksnbeatles

BuddytheReow said:


> More a PSA than anything else to the aspiring breadboard baker, jumper wires make a huge difference. The problem is that a lot of the more flexible wires are either way too long or way too short and can make your layouts quite messy. So, naturally, I started making my own jumpers out of some hookup wire in various sizes and color coordinated. This turned out to be a very tedious and time consuming process and I think I made 1-2 dozen in about an hour by more or less eyeballing the different sizes I needed. A few days ago I bit the bullet and dropped $12 for some hookup wire based jumpers and these are a godsend! Sometimes I'm waaaay too cheap in this hobby thinking I can just DIY everything. $12 saves me hours of tedious work with no circuit built as a result. The small ones in the bottom right corner will be used all the time based on how I layout my boards. The large ones I'm probably not going to use, but you never know.
> 
> I still need to pull the trigger on some breadboard mountable switches which will clean up the layouts even more.
> 
> 
> 
> https://www.amazon.com/dp/B07CJYSL2T?psc=1&ref=ppx_yo2ov_dt_b_product_details
> 
> 
> 
> View attachment 29517


I have that exact wire kit. I was breadboarding an expanded version of my Dumesday Fuzz yesterday trying to figure out a way to turn a no-knob fuzz into a four knob fuzz (I mean, adding knobs is easy— figuring out what kind of controls is the tricky part. Volume? Duh. Fuzz? Idk… it’s got great cleanup with the guitar vol, and doesn’t sound as good just lowering the gain the usual way. Voltage starve? Probably. Tone? But what kind of tone stack— can’t decide. Some sort of envelope controlled q2 bias? Maybe, but maybe too weird) and those jumper wires came in handy as usual


----------



## Feral Feline

I just found my little box of breadboard jumpers the other day, they'd gone missing after skipping across the Great Pond. I've been using regular those shreddable ribbon cables with the pins already attached (male-male & male-female ends), hookup wire and snipped capacitor leads — whatever I could get my hands on, in most cases either too long, too flimsy or...

So glad to have found the box of jumpers, now if I could just find the other assorted jumpers I'd collected beyond what came in the box.

That sums up breadboarding pretty well, ie thinking outside the box. Yes, I'm pretty good at stating the obvious.


----------



## BuddytheReow

Here's the schematic. I've renamed this the *Thunder Fuss* and updated the above post.


----------



## fig

I’ll have to see what all the FUSS is about 
One note on the jumper wires, that bottom-right cell, it will be empty long before the others. I‘ve been using bits of bus wire lately rather than buy more boxes of wires for _just_ those sizes.


----------



## Feral Feline

Buddy, thanks for the schematic — great new name!


----------



## andare

What do you guys use for drawing schematics?
DIYLC is missing a bunch of symbols.


----------



## BuddytheReow

andare said:


> What do you guys use for drawing schematics?
> DIYLC is missing a bunch of symbols.


I use Tiny CAD. DIYLC is just for layouts


----------



## fig

Yes indeed, thank you for all of these.


----------



## andare

BuddytheReow said:


> I use Tiny CAD. DIYLC is just for layouts


Uh-oh, no Mac version. I'll keep looking


----------



## BuddytheReow

This took me a while to draw out. I know it's not the best with 21 cuts and 10 links, but I traced the circuit multiple times and everything seems in order. There is one standing resistor (2.2M), but there is room for you to fold it down. I got lucky with this layout in terms of the Bazz Fuss diode: you can either solder one directly to the board of your choice (anode to Diode + and cathode to Q2 base) or you can make it switchable in two ways. You can either use a DPDT switch to go back and forth between 2 diodes (I would suggest trying a germanium and a "standard" 1n4148) or you can build the daughter board for a 1P7T rotary switch. I bought a rotary a long time ago and this seemed like a good way to incorporate it. While drawing this I had to color coordinate my jumpers: red is power, black is ground, and blue is guitar signal. The board itself will definitely fit in a 125b, but with 6 pots plus a diode selector of your choosing it may be worth your while to put this in a 1590bb. I am in the process of heating up my iron on this one to confirm the layout, but if anyone wants to give it a go they're more than welcome to. I will report my success/failure once finished and update this post here.

One quick note on the layout: Volume 2 to output. Will update the layout shortly.

*EDIT*: see updated layout in below post. This version is not valid


----------



## BuddytheReow

I fired up the iron and tried my *Thunder Fuss* on some vero. I had to troubleshoot it a bit and realized I was crossing some streams at 2 points so I added 2 cuts. This layout and schematic are verified. I half soldered in the original diode from the schematic (didn't trim the leads since I will be removing it if/when I box this up) just to test the circuit. I will experiment on the breadboard for a few minutes but I think I will go with the DPDT switch instead of the rotary. This took me 2 bench sessions plus troubleshooting to get this circuit finalized.

Right now in my building process this truly is "From Breadboard to schematic to reality". Running on cloud 9 until I have to clean up my workbench (boooooooo).

I present to you the *Thunder Fuss*!!!!! Volume 2 to output


----------



## BuddytheReow

Maintenance day today. I’ve been a little unhappy with one of my breadboards, so I swapped it out. Took some time as well to mark some of the dpdt breakout boards with some acrylic pen to let me know where to connect. This is probably a boring post, but sometimes it’s good to clean up the bench even though it happens once or twice a year.


----------



## BuddytheReow

I've been eyeing up Tim Escobedo's circuit snippets for quite some time during my circuit browsing time and thought now is as good of a time as ever to start going through them

First up, the _Pushme Pullyou_



This one seems pretty simple when you break it all down. I only had time today to put together the stock circuit sans volume control and it works. I didn't have a 500k resistor so I used a 510k.

Q1 is a simple 1-transistor fuzz circuit. I threw in a 2n5089, but a 2n3904 will work just fine here. Q2 and Q3 are where the octave magic happens. I _think_ it's because they are both out of phase with one being a NPN and the other a PNP. In general, I think this circuit is ok: it's not horrible, it works, but I think needs a few tweaks or add-ons to make this more workable. If you like the sound as is then by all means keep it. At the end of the day these are merely snippets that _could _act as a standalone effect, but I think they need more refinement. I will judge Escobedo's circuits more of a "look what I made" kind of deal and see what all the fuss is about. 

Anyways, if you want some guidance on how to build it here's my breadboard pic if you're interested.


----------



## BuddytheReow

Next up we have the Rambler. Using a 386 power amplifier chip and a few diodes you can achieve a heavily distorted octave sound. I did not try plugging this directly into a cab like description says, but I'll take his word for it. Given the few parts needed for this it's pretty good and would recommend you trying this one out.


----------



## BuddytheReow

1 post for 2 separate "builds".

First, I finally finished a Micro Protoboard graciously donated by Mr. @PedalPCB himself for the cause of inspiring others to start creating. Between the regular Protoboard and the Micro one, I prefer the larger simply because it allows more real estate to spread out on. That being said, I do appreciate the compactness of the Micro for trying out little ditties or auditioning components.

Naturally, once I finished putting it together I had to build something on top of this build to make sure the first build can work with the second build. Huh? Anyways, here's a very simple booster/fuzz circuit I cooked up in about 5 minutes just to see if the board and protoboard could function. Schematic and breadboard pic are below.

Essentially, this is a blendable input cap going into a single gain stage transistor then to a 10k volume pot. I wanted to grab a different BJT than I normally do (2n5088, 2n5089, or 2n3904) so I gave the BC series some love today with a BC547c. The emitter is jumpered to ground for maximum gain. Frankly, and NPN BJT will work just fine here and you can experiment if you want as well to see what you like.

Dial back the volume on your guitar and this turns into a boost. Dial the input cap pot to the smaller value of the two and you've got a treble booster that works pretty well IMO. Crank your volume knob back up and you've got a light/medium fuzz. Now that I'm writing this it seems that the ideal place for this would be at the beginning of your chain to stack with another effect you have.

5 minutes of my time plus some basic circuit knowledge produced something rather cool. Is it a Booster? Is it a Fuzz? No. I present to you the *Boozzter*.

Now back to your regular progamming.


----------



## Feral Feline

I think I'll lay this Boozzter out on a  GPCB little GBOF-board, after I play around with it on the Micro Protoboard.

Thanks for the inspirations.


----------



## BuddytheReow

I've spent the past week or so putting aside all electronic projects and told myself just to play/practice. Practice? What's that?

I did this with the realization that I've set aside playing for a long time to prioritize breadboarding, soldering, etc. My chops are horrible and need to get back in the groove of things.

This gave me an excellent opportunity to really try out the *Thunder Fuss*. I made 2 tweaks to the circuit.

1. The THICK control really doesn't do anything since the bass can be controlled via the Baxandall. If no active tone stack was in here, then yes it would be more useful. I took it out. C1 in the schematic is no longer needed, but I was too lazy to adjust the ref des for the other caps. The circuit starts with C2 and goes from there.

2. Most of my guitars have pretty hot pickups and dialing back the volume knob does change the overall tone in this circuit. Since I have a pot already wired up I decided to make that a PREGAIN knob. I think 100k may be a bit too high considering there's a 1m pulldown resistor right after it, but it works. I think I will keep this here.

Schematic and stripboard layout have been adjusted. I'm REALLY considering putting in the daughterboard for the diode selection. Right now I've got a DPDT switch with a 4148 and BS170 (very boutique-y).


----------



## BuddytheReow

Finally got around to updating my Thunder Fuss layout. This one is verified and final. Build report to follow.


----------



## music6000

Fussy like this:


----------



## BuddytheReow

music6000 said:


> Fussy like this:
> 
> View attachment 34570


That's pretty sweet looking! Now if someone can make a PCB to get it to fit in a 125b.... I hope someone accepts the challenge...


----------



## benny_profane

BuddytheReow said:


> That's pretty sweet looking! Now if someone can make a PCB to get it to fit in a 125b.... I hope someone accepts the challenge...


Your 19x19 layout should work. I think there’s clearance for 22 columns horizontally.


----------



## BuddytheReow

benny_profane said:


> Your 19x19 layout should work. I think there’s clearance for 22 columns horizontally.


The prototype I made with the rotary switch, probably not. Possibly if a dpdt is used...


----------



## benny_profane

BuddytheReow said:


> The prototype I made with the rotary switch, probably not. Possibly if a dpdt is used...


Take your favorites and put them on the DPDT!


----------



## BuddytheReow

I recently threw together a stripboard layout I found online. This is a muff derivative called the "Ultra Stoner Mk II" by Grind Custom Fx. What called me to build this one is the DOOM switch and SHAPE control. I was thoroughly amazed at the heavy, mid-humped sounds that can come out of this, especially with a detuned guitar. I'm throwing this up here in the thread to show my trace of the layout (pardon the stain on the schematic, I was doing it during my lunch break, haha). It looks like the doom switch throws a coupling capacitor on Q3 from collector to base to remove some of the clipping. The shape control is really where I want to whip out my breadboard and try it out to see if my trace is correct. If so, I think I may have found my new favorite tone stack. I'll try this out today and report back.


----------



## BuddytheReow

I found a schematic of the Mk I and I think I'm pretty close, even though it's drawn a bit differently.


----------



## Chuck D. Bones

What is the value of C17?  The DOOM sw is a hi-cut on the 3rd stage.  

The large coupling caps let more bass get thru for more sludge.

The SHAPE control is the same as the Skreddy P19 COLOUR control, with different component values.  How well does the SHAPE control work?  Or is all of the action at the top end of rotation?


----------



## BuddytheReow

Chuck D. Bones said:


> What is the value of C17?  The DOOM sw is a hi-cut on the 3rd stage.
> 
> The large coupling caps let more bass get thru for more sludge.
> 
> The SHAPE control is the same as the Skreddy P19 COLOUR control, with different component values.  How well does the SHAPE control work?  Or is all of the action at the top end of rotation?


The layout suggests between 1n-4.7n. I'm settling toward 1n. The shape control works pretty well, but not the full range of the pot. Probably the first 2/3-3/4 and then goes away a bit in the last bit while maxing it out.


----------



## Chuck D. Bones

You have pins 1 & 2 connected together on the SHAPE pot, yes?


----------



## BuddytheReow

Chuck D. Bones said:


> You have pins 1 & 2 connected together on the SHAPE pot, yes?


I was lazy and only connected that to pin 2. I probably should jumper them for good practice.


----------



## Chuck D. Bones

I expected most of the action to be between 3:00 and 5:00.


----------



## BuddytheReow

I've got an itch that I can't scratch. I've got a few 1590b enclosures staring at me and they need a use. My current idea is to whip up 2 One Knob Fuzzes in a single enclosure with a single switch to select a fuzz and a single volume knob. Not too difficult I think. I'll put a dpdt switch for the selector (input and output of each fuzz) going to a single volume pot. Yea, that sounds about right.

Anywho, I stumbled down the breadboarding hole of making my own one knob fuzz. Now I know what you're thinking, "There's tons of them out there!" Not really. If you google one knob fuzzes you'll get tons of fuzz faces and DAM Meathead variants. I wanted to make something more original in the true DIY fashion. After an hour or two going back and forth with work (quiet work day but have things to do), I managed to put something together that I really like that I want to share with you all.

Behold, the *NUT FUZZ*. In more simpler terms, this is a shunt feedback amplifier into an asymmetrical BMP clipping stage. Of course you can build this on any sized breadboard since it's just a one knobber.

This circuit is _incredibly _interactive with your guitar knobs. With everything maxxed out you get a lot of low end coming through with the signal hitting the BJT's _HARD _and almost to the point where gating occurs, but not quite. A high gain fuzz/drone sound for sure! As you turn down your guitar's volume knob the gain is significantly reduced, the low end drops out, and the treble comes through a lot to hear pick attack. To reduce the treble further you'll need to back off your tone knob or switch to your neck pickup. With the guitar volume down significantly, almost to the point of 0, you're in the bright, low/medium gain fuzz territory. As you turn down the circuit's volume the low end starts to drop off. I tend to like it more maxxed out, but I can see others tweaking it to their tastes. Maybe some day I'll make this into a PCB, but need to learn the software first. Another day, i guess.

I haven't built this on vero yet, but I took the time to make a layout this afternoon. This will probably be my project tomorrow on my day off before Thanksgiving. If you make this (and I hope you do or at least breadboard it), you'll have a standing resistor and a standing capacitor but you can counter that by just bending the leads a bit to make them more flush with the stripboard. The next one knobber I make I'll decide whether or not to separate the layouts or combine them to fit in the enclosure.


----------



## BuddytheReow

And a breadboard pic for good measure


----------



## Chuck D. Bones

Another cool BtR creation!
It's pretty damned close to the first half of a BMP.  I don't like the bias scheme on the 1st stage because it's too dependent on HFE.  I understand why you do it, but an LPB with the right resistor values will get you the same AC behavior with better DC stability.  Just takes 2 more resistors.

I encourage you to try larger caps for C1 & C2 because it's not just about bass response.  With larger caps, the bias varies as the caps accumulated DC when the circuit is driven hard.  The bias shifting back and forth can cause gating and abrupt changes in timbre.

You can always put R1 & C3 in diagonally, then they don't have to stand up.  Just sayin'.


----------



## BuddytheReow

Chuck D. Bones said:


> Another cool BtR creation!
> It's pretty damned close to the first half of a BMP.  I don't like the bias scheme on the 1st stage because it's too dependent on HFE.  I understand why you do it, but an LPB with the right resistor values will get you the same AC behavior with better DC stability.  Just takes 2 more resistors.
> 
> I encourage you to try larger caps for C1 & C2 because it's not just about bass response.  With larger caps, the bias varies as the caps accumulated DC when the circuit is driven hard.  The bias shifting back and forth can cause gating and abrupt changes in timbre.
> 
> You can always put R1 & C3 in diagonally, then they don't have to stand up.  Just sayin'.


I tried many times altering C1 and C2, both in the standalone first stage and then again once the full circuit was complete. I didn't like the bass response at all using anything bigger (REALLY wanted to use 100nf). It just got too muddled. I did notice some timbre changes while testing it, but they went away pretty quickly and didn't come back, so I just wrote it off.


----------



## Chuck D. Bones

And that's why we build breadboards.  Oversized caps work well in some circuits and not others.  I'm breadboarding this one.


----------



## BuddytheReow

Chuck D. Bones said:


> And that's why we build breadboards.  Oversized caps work well in some circuits and not others.  I'm breadboarding this one.


Chuck, can you recommend a free software for designing PCBs? Also, who's a good vendor for sending a file to manufacture a PCB?


----------



## Chuck D. Bones

A lot of the guys here, including Robert, use DIPtrace.  There is a free version for non-commercial used.  I've fooled around with it a bit, but since there are others here who are already good at it, I usually defer to them.  Fig knows where to order boards.


----------



## Chuck D. Bones

OK, I breadboarded it and it sounds pretty good.  Very bottom-heavy.  I have to wind my guitar's Volume control all the way down to 1 to get anywhere close to clean.  I'm going to install a FUZZ control, similar to the Arctic White Fuzz, to tailor the gain and guitar Volume response.  Yes, I realize it won't be a One Knob Fuzz anymore.


----------



## BuddytheReow

Chuck D. Bones said:


> OK, I breadboarded it and it sounds pretty good.  Very bottom-heavy.  I have to wind my guitar's Volume control all the way down to 1 to get anywhere close to clean.  I'm going to install a FUZZ control, similar to the Arctic White Fuzz, to tailor the gain and guitar Volume response.  Yes, I realize it won't be a One Knob Fuzz anymore.


I agree it’s bottom heavy, but not at the point where it’s unusable. The volume controls on both ends tame it as you turn it down. IMO this makes a good doom/drone sound


----------



## Chuck D. Bones

Breadboarding and playing thru the Fuzz Nuts got me to listen to two of my 2-transistor fuzzes for comparison: Piccola Figa & Folk Fuzz Deluxe. They too are fairly bottom-heavy. All have different tones and to me, sound better with single-coils.


----------



## BuddytheReow

Chuck D. Bones said:


> Breadboarding and playing thru the Fuzz Nuts got me to listen to two of my 2-transistor fuzzes for comparison: Piccola Figa & Folk Fuzz Deluxe. They too are fairly bottom-heavy. All have different tones and to me, sound better with single-coils.


In your opinion is my Nut Fuzz a one trick pony that only I can enjoy or is there potential for others to appreciate it? I'm trying to determine if I like this because of "Look what I made!" or because it's actually decent to someone who's not me.


----------



## BuddytheReow

The stripboard layout is verified. There is a bit of noise floor, but not horrible. It should go away once I box this up


----------



## Chuck D. Bones

I think anyone interested in the Fuzz Nuts should build it and decide for themselves.  For every dirt pedal, there will be someone who loves it and someone who hates it.  I'm somewhere in-between.  You invent cool stuff.  My comments were just that, comments.

My breadboard had a lotta hum, but I chalked that up to the fact that it was on a breadboard with long wires and no shielding.


----------



## steviejr92

Chuck D. Bones said:


> A lot of the guys here, including Robert, use DIPtrace.  There is a free version for non-commercial used.  I've fooled around with it a bit, but since there are others here who are already good at it, I usually defer to them.  Fig knows where to order boards.


DIPtrace you say.....Im going to look into that!


----------



## Chuck D. Bones

You'll need a computer, I don't think you can route boards on an iPhone.


----------



## steviejr92

Chuck D. Bones said:


> You'll need a computer, I don't think you can route boards on an iPhone.


1 step ahead of you sir! Does a beatup Dell that my dad used to use as his work computer work?   Its helped me with all my designs so far....


----------



## Chuck D. Bones

LoL.
Sure, why not?  My main computer is coming up on it's 8th birthday.  The last 5 computers I bought were used.  All are still running strong.

Hey Sandy, sorry to side-track your thread.


----------



## steviejr92

As long as they work i say....


----------



## fig

Chuck D. Bones said:


> Hey Sandy, sorry to side-track your thread.


Ha! It wasn't me this time. 😁


----------



## BuddytheReow

Chuck D. Bones said:


> LoL.
> Sure, why not?  My main computer is coming up on it's 8th birthday.  The last 5 computers I bought were used.  All are still running strong.
> 
> Hey Sandy, sorry to side-track your thread.


Nah, it’s cool. I’m just glad people are reading this thread occasionally 😂


----------



## Fuzzonaut

BuddytheReow said:


> doom/drone sound ...


... is my (bass) sound. I shall try not to forget to try to build this. 

And I do really enjoy reading your threads, by the way - side tracking included.


----------



## BuddytheReow

If you've been following this thread since the beginning you've noticed that my breadboard has changed dramatically. My first board was a few breadboards on top of some cardboard that was duct taped together. Those were the good ol days....NOT! Then I upgraded to a protoboard which was a godsend in and of itself. Having the protoboard itself was nice, but it needed to be mounted on something so I can more easily pick it up off a table instead of trying to get my fingernails under the board. So what did I do? I mounted it on some scrapwood and rounded off the corners with a router, which definitely helps. I've got a tayda order coming which will help attach a 9v battery to the power socket. My current power supplies are mounted under my pedalboard and on my workbench.

I've got a few ideas brewing just like @fig to make the breadboarding experience better, but I need to mess around and try out my ideas.

Anyways, it's all mounted and one of the ideas is to make a small test speaker just to make sure my creations pass signal. So, I built a Ruby amp to test the speaker. It works nicely and may make this a more permanent fixture on my prototype breadboard.


----------



## BuddytheReow

While many of us here like to show off their builds and success stories, it's equally important to mention your failures as well. Why? It helps others to realize that not everything you touch turns to gold. New to pedal making? I'm sure you've had a few bumps along the way or you just got lucky (I don't fall into this category).

I'm sharing this just to show the amount of time needed to pull a circuit out of thin air. The internet is an excellent resource, but it can also provide misinformation as well. I'm currently on the warpath of designing a second 1-Knob fuzz so I can put 2 in an enclosure and make them switchable with only 1 volume pot. The *NUT FUZZ* was a nice one that I cooked up. I'm toying with the idea of a more octave up heavy fuzz. I stumbled upon this topology from David Morrin's site.




Seems simple enough, so why not try it out! With no values from this picture I did some digging and noticed this is similar to the Fender Blender for this particular stage. Resistor values I used are identical on both the collector and emitter, so I went with 6.8K. Fender Blender caps were 10u so I duplicated that as well. The diodes from memory work best when the voltage drop is small, so I used 1n5817s. This stage by itself doesn't pass signal very well and needs an input gain stage. Throwing a shunt feedback amplifier with distorted tone in there produced something, but not as octave-y as I'd like. Sigh. Perhaps I should go back to the drawing board or just pull the trigger on a fuzz face/DAM Meathead derivative of my own, but make it gnarlier.

Anyways, here's 2 projects on my breadboard. One is what I described above and the other is a circuit I cooked up from @Chuck D. Bones contest early this year. The *PLOPS OF DOOM*. It still needs some tinkering to get it to work the way I want it to, but the "stock" circuit is ok and needs some oscillation tampering. You can read about it here. https://forum.pedalpcb.com/threads/what-another-contest.10105/page-10#post-101594

We need another circuit design contest. That was a lot of fun.


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## BuddytheReow

I've got a project where I need more than 9 volts, but I only have a 9v power supply. Here's a charge pump based on the protoboard's power section. I need to test the layout myself, but it should work. I want to put this in a 1590b with some other goodies. When I get a few minutes of bench time I'll see if this works. Note the 2 cuts under the IC itself. Yes, you won't get 18v since you'll lose a bit of voltage due to the diodes, but it's close enough.

Edit: Layout is verified and updated with an additional cut.


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## BuddytheReow

Tayda order came today. With my mounted protoboard, I finally was able to make my battery a plug in instead of pulling out cables from under my pedalboard. It works rather nicely, don't you think?


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## BuddytheReow

Trying to upgrade my bench and prototyping. This is a power amp that @fig graciously sent me so I could hook up a breadboard to a speaker on my workbench. The power supply I have is  9v daisy chain, but I put the charge pump I posted above in it to increase the headroom. I still need to dial in the gain/volume to minimize the distortion. This is getting "mounted" next to a shelf to make it more permanent until I find a better idea.


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## BuddytheReow

*ZENER DIODES*

What are they? Why should I care? How are these used in guitar pedals?

All excellent questions! Let's dive in to see what all the fuss is about. No graphs or complex math here. Read on to learn more!

I took the time to figure out (with a little Google help) about these and how I can apply it to a project I'm currently working on. If you want to read more about my project then check this out! It's going to be an ultra-breadboarding experience that I may tweak later on down the road.

Here is the schematic symbol for a zener diode.




For this post and purposes of my project/experiment I pulled out a bag of 9.1V zener diodes (1N4739). Putting them through my TC-1 tester shows there's nothing special about them at all with a simple voltage drop of 0.7V. The tester confirms the little black ring is the cathode.





That's weird. I bought these for the 9.1V purpose. Hang on! We need to talk about "zener" breakdown voltage. What is this? Well, if you run some small current from anode to cathode you will see the result above and the diode "steals" about .7 volts before current passes through. What happens when you run current in the opposite direction? Here's where the magic begins....

Whenever you want to test a diode, *ALWAYS* make sure you have a current limiting resistor (CLR) of some kind. For me, I used a 470 ohm resistor.

We can arrange the CLR and diode to test where this voltage drop occurs. Like this. Your DMM should be where V Out is.



As the voltage/current passes through it hits the diode and doesn't allow anything to pass *UNTIL* it reaches the 9.1V threshold. Anything above that voltage gets passed through the diode.




As an experiment, I threw a passive buzzer at the end of this circuit to act as an overvoltage alarm. The buzzer needs about a Volt in order to kick on.





Pretty neat, huh?

Ok. Let's flip the diode and resistor around to look like this:




This configuration will then act as a *faux voltage regulator*. A great way to protect your circuits from accidentally putting too much juice into it. Again, use your DMM at the V Out point. You can see I'm giving it 10V, but only about 9V are coming through. That's because once the diode reaches it breakdown voltage anything over that gets thrown to ground.










Pretty cool, huh?

Ok. Now the question you've really been asking. "How does this apply to guitar pedals?" Let's take a look at a SHO (Super Hard On) schematic. This is the PedalPCB CrackleJack, or at least a portion of it.



See anything familiar yet? That 1N4739 is a 9.1V zener diode that acts as a voltage regulator! As the current passes through from above my little snippet through R2 and into the gate of Q1 it has to touch the zener diode. Anything over 9.1V applied to Q1 will automatically get dumped to ground and saves your BS170 from getting fried by accidental static discharge.




The same concept is true for all zener diodes. *A word of caution*. Make sure you're orienting the diode the correct way in order for these little circuit legos to work. Otherwise you may accidentally fry one like I did testing this out.

The more you know.....

BuddytheReow


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## BuddytheReow

Here's another charge pump I put together on a breadboard and it works nicely. Utilizing the charge pump already on the protoboard I was able to (with a little help from Google) turn a 9v input into -9V, 18V, and 25V. I tried the next step up and hit about 35V and panicked since my capacitors are only rated at 35v.





I then took a bit of time to draw a vero layout since this is going on my BuddyBoard project I'm working on. This isn't verified yet, but it looks ok to me so far. If it doesn't work I'll have sacrificed 5 electro caps. Not that they're expensive; I just don't have a lot of 10uf ones.

Edit: This layout is verified and works nicely.


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## BuddytheReow

A while ago I put together a simple, but gnarly one knob fuzz, the *Nut Fuzz. *See post #208. I want to put this in an enclosure with another one knobber, but still gnarly. I think I've found it. I went through a lot of my old stripboard builds from when I was starting out and during quarantine. This is the *Phantom Octave* fuzz I built from tagboard effects. These 2 will get boxed up when the time comes. Both of these shine with a detuned guitar IMO.








						Fuzzhugger Phantom Octave
					

Collection of vero (stripboard) & tagboard layouts for 100s of popular guitar effects, with over 500 verified designs. DIY your own boutique effects!




					tagboardeffects.blogspot.com


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## Sturdag Lagernathy

Definitely gonna try this one! The Ultrastoner was a great recommendation, totally right about the EQ on that one. Have you checked out the Mountainking Megalith? Think you'd dig it!


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## BuddytheReow

Sturdag Lagernathy said:


> Definitely gonna try this one! The Ultrastoner was a great recommendation, totally right about the EQ on that one. Have you checked out the Mountainking Megalith? Think you'd dig it!


No I have not. I’ll check it out


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## Feral Feline

Apparently I need to fry a few transistors with some backwards diodes.

I just read post #234 and when I finished I noticed I'd already given it the thumbs up — so I must've read it before and not learned the lesson well enough to remember it and realise I was *re*-reading the post.


So I guess this missive is really just me trying to say: 
Thanks @BuddytheReow, for all the tutelage you've provided us forumites, and public-lurkers alike.


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## BuddytheReow

Now that my BuddyBoard is up and running, I decided to go through my blank PCBs that need to be built and breadboard them. A "try it before soldering it" scenario. This is a Madbean Pig Butt, which is essentially the Dream Fuzz here (Opamp Big Muff). The only difference that I could see is the tone bypass switch (spdt vs dpdt). I see the logic in both. This is the stock circuit and works pretty well for what it is. I may try to add a MID control in the tone stack and tweak some other values before committing to solder.

I also picked up some smaller jumper cables for pots/switches. They make the board look a little nicer IMO. I still need to get some F/F smaller ones too, but that will be on my next Tayda order soon.


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