# First Pedal PCB Build: The Muffin



## Big Monk

I'm going to use this thread to document my build on the Muffin board.

I'm using the schematic values from Kit Rae's site for the Version 2 Violet Ram's Head 1972 #5 unit:





I have a whole stash of Amperex A115 transistors that I bought from Small Bear in the hopes they actually delivered around the gain bucket Steve showed. I wanted to  use them for Axis Face Silicon Fuzz units. Turns out his hFE bucket was low for some reason. Most of them were over 150, with a distinct gathering around 175-200. Not so great for what I bought them for but good for the more traditional Silicon Fuzz Face and, as it turns out, this project. I decided to go with Kit Rae's site again where he singles out 2 exceptional Violet Ram's Head units with all 4 transistors in the 160-200 hFE range:




I ended up picking a fairly matched set of A115 units:

Q1, Q2, Q3 = 171 hFE
Q4 = 164 hFE

I had some 1N456 diodes left over from my Ampeg Scrambler parts so I grabbed 4 of those centered around a Vf of 756 mV. Nothing special other than they look really cool.

The last thing I am working on right now is the tonestack. I'm going for more of a Gilmour thing here and plan on using this by itself but also EQ'd by a Vick Audio Overdriver. My little Single Ended EL84 amp is fantastic for my home playing and the Drive control I installed gives me a broad range from clean to semi-dirty to full out crunch. It has a reasonable amount of mid-range content when driven so I don't want to do anything crazy with the tonestack except to flatten out the mid-scoop a touch.

So, I went to the Duncan TSC:





In the form you see in the schematic, there is a -12.5 dB mid scoop at around 1kHz when the tone control is at 50%. I wanted to bump this up a bit but not quite flatten it out as I have a somewhat mids-forward amp and ways to adjust the mids should I need to. I'm still not certain how I'll end up configuring it, but I'll likely just pick an appropriate value for C9 and call it a day.

Here are the TSC charts for C9 = 6.8 nF and 8.2 nF, respectively:







The mid-scoop at 50% Tone goes up to -8.3 dB and -9.4 dB respectively.

Lastly, here is the mockup with controls and mechanicals attached to the Tayda Ball Silver enclosure:








Should find some time this week to get everything wired up.


----------



## almondcity

let me know where you end up on the tone control values, I've been messing with these myself quite a bit lately


----------



## Big Monk

almondcity said:


> let me know where you end up on the tone control values, I've been messing with these myself quite a bit lately



I think I'm simply going to play with C9. It seems to have the most effect on the mid-scoop. With 39k resistors in R5 and R8, changing C9 shifts the mid-scoop up towards flatness at 50%. 

My gut says I'll go with 0.0068 uf there. That reduces the mid-scoop from -11.4 (ish) dB to around -8.3 dB. I don't want to flatten it too much given my amplifier and the fact that I play a Les Paul much of the time as well.


----------



## almondcity

I've been going with lower values of that, like 3.3nF and 2.7nF

I originally started messing with these based on the Elk Sustainar which had like 390pF, but it sounded very bad lol

I know the R and C values form low and high pass filters, but I don't understand what effect changing the cap vs changing the resistor has


----------



## Big Monk

almondcity said:


> I've been going with lower values of that, like 3.3nF and 2.7nF



What I am thinking of doing is having my "scoop reducer" cap value on a switch. This way I can "deepen" the scoop when playing my Les Paul and make it less shallow with my Strat.


almondcity said:


> I know the R and C values form low and high pass filters, but I don't understand what effect changing the cap vs changing the resistor has



I'm not an expert either on the BMP tone control. As a general rule, tweaking C9 up will raise the mid-scoop toward flatness, while tweaking C8 down will do the opposite. Tweaking either R5 or R8 down seems to deepen the mid-scoop.

Have you used the Duncan Tone Stack Calculator before?


----------



## almondcity

I have not, I've been basing my decisions based off info from this page:









						Coda Effects: Big Muff tonestack : dealing with mids frequencies
					

Learn more about electric guitar related electronics: DIY guitar pedals, from fuzz faces to delays and reverb, cables and circuits theory




					www.coda-effects.com


----------



## almondcity

to add, as a guitarist I've generally come to dislike the left half of the tone knob and so I've pushed the low pass filter up towards 1000 Hz (smaller R and C values) to get useable sounds from the full turn of the knob

no mud or flabbiness here


----------



## Big Monk

almondcity said:


> I have not, I've been basing my decisions based off info from this page:
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Coda Effects: Big Muff tonestack : dealing with mids frequencies
> 
> 
> Learn more about electric guitar related electronics: DIY guitar pedals, from fuzz faces to delays and reverb, cables and circuits theory
> 
> 
> 
> 
> www.coda-effects.com



I'd recommend the Duncan TSC:





__





						Download
					





					www.duncanamps.com
				




It lets you see how how the component changes the frequency response. 

When you look at the mid control on the Hoof, you can see that it actually makes the scoop much deeper at it's minimum, as the pot is in series with a very small resistor. At the maximum value of the mid control it's just a touch under flat at 50%


----------



## almondcity

yeah i need to try that when i have a minute, thanks


----------



## Big Monk

So, I decided to drill a small hole where I had room inside near the switch:





My logic is simply to switch the C9 to compensate for when I go between my Les Paul and Strat.

First thing I’ll do is decide on the depth of the mid-scoop (LP setting) then decide on a flatter setting (Strat Setting).


----------



## Feral Feline

Awesome planning and preparation. 

I tend to plan things in depth, but I'm nowhere as meticulous as you're being with this build — it's opening my mind up to thinking beyond the box (literally), I must reconsider the entire signal chain and all its influences. 


I'm still planning my first Muff build, so this is very inspirational.


----------



## Big Monk

Feral Feline said:


> Awesome planning and preparation.
> 
> I tend to plan things in depth, but I'm nowhere as meticulous as you're being with this build — it's opening my mind up to thinking beyond the box (literally), I must reconsider the entire signal chain and all its influences.
> 
> 
> I'm still planning my first Muff build, so this is very inspirational.



Thank you! I guess my thing is planning so I have no mistakes and also so I don’t regret component choices, etc. For me, I like to build things that far exceed what I could have bought and that occupy pride of place on my board.

I’m trying to accomplish a couple things:

1.) The Gilmour BMP Sound. I think the tweaks to the Violet Ram’s Head base will get me there. Also, I just purchased a Vick Audio Overdriver to use with it.

2.) A versatile BMP tone. I think with the mid-scoop switch, this will also be stellar with my Les Paul.


----------



## Feral Feline

For versatility, why not 3 tones? C9a, C9, C9b

I really like how Aion uses an on-on-on DPDT where most would use an on-off-on. 

The difference is with on-*off*-on you've got Flat-Scooped-Bumped in the switch positions.
Using the on-*on*-on, you get a logical (to me) Scooped-Flat-Bumped set of switch positions. 


Any plans to build your own Colorsound PowerBooster?


----------



## Big Monk

Feral Feline said:


> For versatility, why not 3 tones? C9a, C9, C9b
> 
> I really like how Aion uses an on-on-on DPDT where most would use an on-off-on.
> 
> The difference is with on-*off*-on you've got Flat-Scooped-Bumped in the switch positions.
> Using the on-*on*-on, you get a logical (to me) Scooped-Flat-Bumped set of switch positions.


I don’t think I need boosted mids. My modified single-ended EL84 is mid-forward and I can always EQ a mid bump on my 6 band if need be. I want it just under flat for my Strat and fully scooped for my Les Paul.

Plus I only have DPDT switches on hand! I do like your point though.


Feral Feline said:


> Any plans to build your own Colorsound PowerBooster?



Nope! Just splurged on a Vick Audio Overdriver. It can be powered with 9vDC or 18 vDC, which I have on my power supplies, so it’s essentially an Overdriver and Powerboost.


----------



## Big Monk

So, I think I have settled on tonestack values:

High and Low-pass Resistors = 33k
High-pass Cap = Switchable 

0.0047 uf (Les Paul) 





0.0082 uf (Strat)




Low-pass Cap = 0.01 uf


----------



## almondcity

I messed around with the tone stack calculator a bit yesterday

I still don't really understand what's actually happening because while the program may tell me one thing, my ears tell me another...for instance I seem to get more treble at the lowest setting on the tone knob vs at the middle position, something the graph cannot back up

I'm keeping my high pass cap (C10) at < 4nF and I will die on this hill 👀


----------



## Big Monk

almondcity said:


> I messed around with the tone stack calculator a bit yesterday
> 
> I still don't really understand what's actually happening because while the program may tell me one thing, my ears tell me another...for instance I seem to get more treble at the lowest setting on the tone knob vs at the middle position, something the graph cannot back up
> 
> I'm keeping my high pass cap (C10) at < 4nF and I will die on this hill 👀



Actually, I think what you are hearing is EXACTLY what the graph is showing you.

i don’t have it in front of me but on “10” you have a bump in highs and a roll off of lows. On the other hand, the tone control on “0” shows a steep roll off of highs.


----------



## almondcity

I think what I'm hearing is actually more mids being brought in at 0 than at 5. Basically the middle setting on my latest big muff is the worst spot but everywhere else is fire


----------



## Big Monk




----------



## Big Monk

So, this is a first.

Got the circuit all wired up:







The circuit works wonderfully. The mid-scoop switch worked like gangbusters. 

But, the LED won’t light up. How’s that for the polar opposite of what you would have expected when you were a newbie? Perfectly functional circuit on the first try but no LED. 

I checked the obvious: it’s oriented properly, I did a continuity check from power to switch, etc. I tried a different LED. 

I guess I’ll have to remove the whole circuit from the enclosure and check my connections from the underside. 

Anyone have any ideas?


----------



## Big Monk

So in the interest of not messing up the board trying to get the LED to work “on board”, I simply jumped the board connections all together and wired right to the DC jack and stomp switch. It’s nice and discrete and everything is working. 

Full volume tests to come.


----------



## peccary

Big Monk said:


> So, this is a first.
> 
> Got the circuit all wired up:
> 
> View attachment 14376View attachment 14377
> 
> The circuit works wonderfully. The mid-scoop switch worked like gangbusters.
> 
> But, the LED won’t light up. How’s that for the polar opposite of what you would have expected when you were a newbie? Perfectly functional circuit on the first try but no LED.
> 
> I checked the obvious: it’s oriented properly, I did a continuity check from power to switch, etc. I tried a different LED.
> 
> I guess I’ll have to remove the whole circuit from the enclosure and check my connections from the underside.
> 
> Anyone have any ideas?



I might be crazy, but I feel like I read on here that some folks had LEDs (from Tayda?) where the long leg was the cathode. Should be an easy "just in case" check either way.


----------



## peccary

Big Monk said:


> So in the interest of not messing up the board trying to get the LED to work “on board”, I simply jumped the board connections all together and wired right to the DC jack and stomp switch. It’s nice and discrete and everything is working.
> 
> Full volume tests to come.



I didn't realize that there was a second page here, just to explain my oddly late reply 🤣

That seems odd you got it to work that way - does that mean it might have been the switch?


----------



## Big Monk

peccary said:


> I didn't realize that there was a second page here, just to explain my oddly late reply 🤣
> 
> That seems odd you got it to work that way - does that mean it might have been the switch?



There are two scenarios I see:

1.) I boogered the on-board LED circuit;

2.) A mismatch between the Muffin board and the 3PDT breakout board.


----------



## Big Monk




----------



## burger-patty-and-bacon

Big Monk said:


> But, the LED won’t light up. How’s that for the polar opposite of what you would have expected when you were a newbie? Perfectly functional circuit on the first try but no LED.


I had an identical issue very recently and in my case, the PCB itself had no continuity between SW and the "K" of the LED.  I soldered a jumper directly from SW and K LED pad on the PCB itself and my LED worked.  No idea why the trace/pads were not linked but that was my issue.


----------



## Big Monk

burger-patty-and-bacon said:


> I had an identical issue very recently and in my case, the PCB itself had no continuity between SW and the "K" of the LED.  I soldered a jumper directly from SW and K LED pad on the PCB itself and my LED worked.  No idea why the trace/pads were not linked but that was my issue.



In the end it turned out fine. I did the age old “solder an Resistor online with the LED” setup and went straight from the DC jack to the switch. It tucked nicely under the board and the heat shrinked resistor is hugging the side of the switch.

I just left the LED resistor on the board. I didn’t want to try and troubleshoot on the board and mess everything else up.


----------



## Big Monk

So, an anecdote:

I finished up my Aion Ares today and same issue. Circuit worked first time but no LED. I flipped it, still no LED. Continuity check from power to LED was good.

Ended up repeating what I did with my Muffin and jumped in a classic LED string with resistor in line and direct to switch.

Is this a common thing or am I crazy?


----------



## Robert

On either of these builds, were the leads of the LED touching the metal LED bezel?


----------



## Big Monk

Robert said:


> On either of these builds, were the leads of the LED touching the metal LED bezel?



On the Ares, no. Now that you say it, I can’t remember on the Muffin, although I’m pretty sure the bent leads still had clearance.

Thank you for this. I’m gonna keep this in mind on future projects.


----------



## Coda

Big Monk said:


> On the Ares, no. Now that you say it, I can’t remember on the Muffin, although I’m pretty sure the bent leads still had clearance.
> 
> Thank you for this. I’m gonna keep this in mind on future projects.


The legs on mine were well insulated from the bezel. Also, when I installed the second one, I soldered it before installing into the bezel. Dead for both. Literally dead, once removed, neither  LED worked anymore.


----------



## Big Monk

Coda said:


> The legs on mine were well insulated from the bezel. Also, when I installed the second one, I soldered it before installing into the bezel. Dead for both. Literally dead, once removed, neither  LED worked anymore.



The more I think about it, I don’t believe the Muffin had the leads touching either.


----------



## Big Monk

Robert said:


> On either of these builds, were the leads of the LED touching the metal LED bezel?



Turns out I need a lower RLED. I kept the jumped in LED for the Muffin and my Aion Ares but just subbed in a 1k on my Tearjerker build and it lit right up.


----------



## Chuck D. Bones

almondcity said:


> I've been going with lower values of that, like 3.3nF and 2.7nF
> 
> I originally started messing with these based on the Elk Sustainar which had like 390pF, but it sounded very bad lol
> 
> I know the R and C values form low and high pass filters, but I don't understand what effect changing the cap vs changing the resistor has


The resistor and cap both do the same thing.  You can fiddle either one.  No magic here, use TSC and your ears to find what you like.  Personally, I like it flat in the middle and I don't want the treble side to sizzle too much.  You can even leave out the resistor on the treble side (R2 on the TSC) for less bass cut.  A very versatile and often misunderstood tone control.


----------



## Chuck D. Bones

Big Monk said:


> So, an anecdote:
> 
> I finished up my Aion Ares today and same issue. Circuit worked first time but no LED. I flipped it, still no LED. Continuity check from power to LED was good.
> 
> Ended up repeating what I did with my Muffin and jumped in a classic LED string with resistor in line and direct to switch.
> 
> Is this a common thing or am I crazy?


The only time I had problems with LEDs on PPCB boards it was self-inflicted.  Wiring error, bad solder joint at the switch or LED lead touching the bezel.  I recommend putting some insulation on the LED leads so they can't make electrical contact with the bezel.


----------



## Big Monk

Chuck D. Bones said:


> The only time I had problems with LEDs on PPCB boards it was self-inflicted.  Wiring error, bad solder joint at the switch or LED lead touching the bezel.  I recommend putting some insulation on the LED leads so they can't make electrical contact with the bezel.



In this case, the stock RLED in the build doc was simply too high. I dropped it to 1k and it was all good. 

4.7k seems pretty high to me in general.


----------



## Chuck D. Bones

Depends on the LED.  The aqua LEDs I use are way too bright with 4.7K; I use 22K with those.  The UV LEDs I have need 1.5K or lower to be visible.


----------



## fig

Chuck D. Bones said:


> The resistor and cap both do the same thing.  You can fiddle either one.  No magic here, use TSC and your ears to find what you like.  Personally, I like it flat in the middle and I don't want the treble side to sizzle too much.  You can even leave out the resistor on the treble side (R2 on the TSC) for less bass cut.  A very versatile and often misunderstood tone control.


Thank you for this. I had a note to study this interaction and this gem will fit nicely.


----------



## Big Monk

Chuck D. Bones said:


> Depends on the LED.  The aqua LEDs I use are way too bright with 4.7K; I use 22K with those.  The UV LEDs I have need 1.5K or lower to be visible.



Right! Lesson learned for for me. I’ll breadboard the LEDs from now on to get the right value resistor.


----------



## Chuck D. Bones

fig said:


> Thank you for this. I had a note to study this interaction and this gem will fit nicely.


If you want to simulate removing R2 in the TSC, make R2 10MΩ.  Experiment with different tapers because for some R & C values, most of the action is at one end of the TONE pot's rotation.


----------



## almondcity

Not to hijack the thread but I really like my latest build with pots for the tone stack resistors. It's such an easy mod and so useful for different tones. My approach has been to set them at about stock values, set the tone knob where I want it, then use the LP and HP knobs to tweak the amount of mids I want


----------



## Big Monk

A quick update.

I think after I get through building my Paragon Mini, Kliche Mini and Electrovibe, I'm going to redo a few things on my Muffin build. 

Talking in another thread with @Coda I realized that while in my mind I targeted the 1973 #3 or "Gilmour" Ram's Head, I actually built the oddball 1973 #5 unit. There ism not a ton of difference but let's look at it together quick:









There are not that many differences. The input resistance goes up in the #5, limiting the gain a touch. The limiting resistors go down in the #5 which bumps up the gain a bit. The Sustain resistor is larger in the #5, so in practice, you can't put the Sustain as low as on the #3. 2 of the collector resistors are higher in the #5 which reduces gain into those stages a touch. The #5 uses 560 pf filter caps in the clipping stages and therefore has a bassier response. Finally, the tone stack is a bit more scooped in the #5.

To me, the input resistance and limiting resistor changes are a bit of a wash. The #3 boosts the input but limits the interstage gain and the #5 does the opposite. What i need to decide is whether the collector resistance makes a big enough difference in light of the fact that I used transistors with much lower gain than typical for a Big Muff.

What I may do is tweak the collector resistors, clipping filter caps and see how I like it. 

Not 100% sure yet though.


----------



## carlinb17

if you have a dmm with a diode setting you can touch the red probe to the a side of the led and the black to the k side if you wired it right it will light up, if not try it the other way and you can then tell if it's correct. red to a black to k


----------



## Big Monk

carlinb17 said:


> if you have a dmm with a diode setting you can touch the red probe to the a side of the led and the black to the k side if you wired it right it will light up, if not try it the other way and you can then tell if it's correct. red to a black to k



Thanks. I solved the LED issue a while ago.


----------



## carlinb17

Big Monk said:


> Thanks. I solved the LED issue a while ago.


my bad when I clicked on the thread it brought me to top for some reason... good to hear you got it


----------



## Chuck D. Bones

You may have a hard time hearing the difference between the two and even then only at extreme control settings.  Given that EHX had a habit of building their pedals with whatever parts were lying around on a particular day, unless someone verified all of the component values in Mr. Gilmour's personal BMP, it's all just conjecture.


----------



## Big Monk

Chuck D. Bones said:


> You may have a hard time hearing the difference between the two and even then only at extreme control settings.  Given that EHX had a habit of building their pedals with whatever parts were lying around on a particular day, unless someone verified all of the component values in Mr. Gilmour's personal BMP, it's all just conjecture.



I'm inclined to agree here. 

EHX made a point of doing something that I advocate: Tweak the circuit based on what you have. You see that many of the changes to the circuits are almost about balancing. 

If one version had a 33k input resistor, 10k limiting resistors and 10k collector resistors, another might have a 39k input resistor, 8.2k limiting resistors and a mix of 10k and 15k collector resistors. You can plainly see this is about balance. Maybe they have a ton of 39k resistors one run and they tweaked the circuit to balance everything out.

Obviously the tonestack tweaks make a difference based on what you want. One of the things that seems to come very starkly when you research is that units with lower gain transistors (by accident of course because keeping with EHX's philosophy in those days, you "use what you got") seem to have a special thing going on.

I may simply tweak the tone stack and be done with it. I personally like the tone but would maybe just like a touch less of a scoop in the stock position of my mid switch.


----------



## Chuck D. Bones

Big Monk said:


> If one version had a 33k input resistor, 10k limiting resistors and 10k collector resistors, another might have a 39k input resistor, 8.2k limiting resistors and a mix of 10k and 15k collector resistors. You can plainly see this is about balance. Maybe they have a ton of 39k resistors one run and they tweaked the circuit to balance everything out.


That's not plain to me at all.  It might be the case, but it might also be random.  33K vs 39K in the tone stack makes little difference if both sides of the tone control are varied by the same amount in the same direction.  

The collector resistor doesn't matter in the first three stages because they have local feedback loops controlling the freq response, clipping and gain.  As long as the resistor isn't so large or so small that it messes up the biasing, it doesn't matter whether it's 10K or 22K.

The current-limiting resistors (R12 & R19) matter because they set the max gain of the stage.  But a 20% change from 10K to 8.2K makes very little difference.  R19 only matters when SUSTAIN is dimed.

The input resistor (R2) has some effect, but the pickup impedance and guitar control setting have a much stronger effect.

The parts in a BMP that have the strongest effect are the coupling capacitors (C1, C3-C7 & C13) and the Rs & Cs in the tone stack.


----------



## Chuck D. Bones

With the lower gain transistors, have you tried replacing the transistors one at a time with lower gain to see which ones effect the tone the most? I think HFE mainly affects the biasing and the 4th stage is the most sensitive to changes in biasing.  There could be something else going on, but that's my best guess based on analysis.


----------



## Big Monk

Chuck D. Bones said:


> That's not plain to me at all.  It might be the case, but it might also be random.  33K vs 39K in the tone stack makes little difference if both sides of the tone control are varied by the same amount in the same direction.
> 
> The collector resistor doesn't matter in the first three stages because they have local feedback loops controlling the freq response, clipping and gain.  As long as the resistor isn't so large or so small that it messes up the biasing, it doesn't matter whether it's 10K or 22K.
> 
> The current-limiting resistors (R12 & R19) matter because they set the max gain of the stage.  But a 20% change from 10K to 8.2K makes very little difference.  R19 only matters when SUSTAIN is dimed.
> 
> The input resistor (R2) has some effect, but the pickup impedance and guitar control setting have a much stronger effect.
> 
> The parts in a BMP that have the strongest effect are the coupling capacitors (C1, C3-C7 & C13) and the Rs & Cs in the tone stack.



I’m not saying all that stuff matters from a technical standpoint, just that historically, EHX was known to buy components in bulk from surplus sources. That explains the variation in actual components and could also explain the slight variations in circuit components. 

Kind of like, “Hey Mike! We got a metric helluva ton of 39k resistors we need to use. Want us to tweak a few other components to keep the signal the same?”

Whether that actually happened is pure conjecture but it would explain relatively minute differences even within a specific version run of the 70s BMPs. 

I agree with you that filter caps in the clipping stage, coupling caps and the tonestack produce the most profound effects. That’s part of why I may just leave mine as is. 

I need to play around a bit more and see what I come up with.


----------



## Big Monk

Chuck D. Bones said:


> With the lower gain transistors, have you tried replacing the transistors one at a time with lower gain to see which ones effect the tone the most? I think HFE mainly affects the biasing and the 4th stage is the most sensitive to changes in biasing.  There could be something else going on, but that's my best guess based on analysis.



I haven’t. My Ram’s Head circuit has 4 Amperex A115 around 171 hFE. I went with those at the outset.


----------



## Chuck D. Bones

171 is not exactly "low gain."  It's a subjective term, I know, but in many, maybe most circuits, once you get above a threshold HFE, it just doesn't matter what HFE you have.  One of these days, I'll breadboard a BMP and play around with various transistors to see if I can tell the difference.  I know from experience that the last stage has enough gain that some TONE control settings will drive the last stage into clipping.  Changing the HFE affects the bias and that will move it closer to, or further from saturation.


----------



## Coda

I’m glad I mentioned it, because this has turned into a very interesting and useful thread.


----------



## Big Monk

My Muffin went in for surgery today and I’m glad to report is recovering nicely. Put on the black pointers in preparation for the fancy new enclosure:






Went with the 1973 #3 Ram’s Head and added an On-Off-On Mids switch for Stock-Flat-Boost.


----------



## Big Monk

I just need to troubleshoot the tone control.

At the crossover point between low and high pass filters, namely the treble side, it drops the volume of the pedal and there is not treble side effectively.  I need to double check my tone stack changes and make sure my joints are good.

EDIT: I imagine the high pass filter resistor is floating. @Chuck D. Bones and @Coda, what do you guys think?


----------



## Chuck D. Bones

Seems like the high-pass resistor is a like candidate.  Check everything.  It's easy to disturb something unintentionally when making changes.


----------



## Big Monk

Chuck D. Bones said:


> Seems like the high-pass resistor is a like candidate.  Check everything.  It's easy to disturb something unintentionally when making changes.



We were close! Looks like I disturbed the trace that’s connected from the high pass capacitor to the tone control. I jumped it and it’s working now.


----------



## Big Monk

One thing I noticed is I seem to have continuity between pins 2 and 3 of the tone pot. 

Looking at the schematic I don’t see how that’s possible and I can’t seen anything bridged in that area. 

Does not seem to be affecting anything but weird nonetheless.


----------



## Big Monk

Gents,

I had some time this morning to play this at moderate volumes.

Short story: I’m floored. I was not unhappy with the 1973 #5 version I had built, necessarily but it was a bit wooly and didn’t cut how I wanted it to with the tone control down. Changing to the 1973 #3, or the so called “Gilmour Muff” has really changed the whole character.

For the sake of posterity, my mid switch is an On/Off/On with 4.7 nF in the middle, 22 nF on the Boost side and 6.8 nF on the Flat side. Tons of versatility.

Im very happy. Many thanks to @Coda  for kickstarting my researches into modifying my original.

I have a sweet UV printed enclosure coming for it:


----------



## Coda

Very nice. You know, I was thinking the other day how I always chuckle when I hear someone talking about their pedalboard, like on YouTube, and they say "Big Muff Pi," and then don't specify which version. Then I remember that only crazy people know that there are tons of circuit variations, most that make no difference (although, I CAN hear it), and that if you don't specify the "generation" (Triangle, Ram's Head, etc.), the "class" (year), and the circuit (#), you aren't actually telling anything other than "I have a pedal"...


----------



## fig

Big Monk said:


> One thing I noticed is I seem to have continuity between pins 2 and 3 of the tone pot.


That can happen if you are close to dime. Try it with a loose pot.


----------



## Big Monk

fig said:


> That can happen if you are close to dime. Try it with a loose pot.



Yup! I figure it was something to do with having enough contact to make continuity internally. 

Like I said, it was not affecting the sound so I figured it was something silly.


----------



## Big Monk

Coda said:


> Very nice. You know, I was thinking the other day how I always chuckle when I hear someone talking about their pedalboard, like on YouTube, and they say "Big Muff Pi," and then don't specify which version. Then I remember that only crazy people know that there are tons of circuit variations, most that make no difference (although, I CAN hear it), and that if you don't specify the "generation" (Triangle, Ram's Head, etc.), the "class" (year), and the circuit (#), you aren't actually telling anything other than "I have a pedal"...



It’s the same when some “influencer” says “Tone Bender”. Which one?

I was deep into homebrewing for a while and the same goes for “Belgian” beer. Which one? Flemish red and brown sours? The Trappist ales? Belgian lager? Abbey beers? Wit biers? 

I’ve become enamored with the Big Muff and the variations. My plan is to purchase 4-5 Muffin boards next time I place a PedalPCB order. 

I want the “Standard Triangle” circuit, the Green Russian, etc. Now that I am starting to understand how to use them, I appreciate the variations.


----------



## Coda

Big Monk said:


> It’s the same when some “influencer” says “Tone Bender”. Which one?
> 
> I was deep into homebrewing for a while and the same goes for “Belgian” beer. Which one? Flemish red and brown sours? The Trappist ales? Belgian lager? Abbey beers? Wit biers?
> 
> I’ve become enamored with the Big Muff and the variations. My plan is to purchase 4-5 Muffin boards next time I place a PedalPCB order.
> 
> I want the “Standard Triangle” circuit, the Green Russian, etc. Now that I am starting to understand how to use them, I appreciate the variations.


The Triangle BOM is the classic one, to my ears...though I have not compared the schematics. The Russian is also great as is. I built a Russian/Civil War in the same box, since there are only 4 differences between them, and I toggle between them. My next Muff will the the Mascis specs. His version is a weird one: its a Ram's Head enclosure, but the circuit is almost identical to the Black and Red (or is that Red and Black?) Muffs. I'm thinking of adding your tone mod to it.


----------



## Bricksnbeatles

Big Monk said:


> It’s the same when some “influencer” says “Tone Bender”. Which one?
> 
> I was deep into homebrewing for a while and the same goes for “Belgian” beer. Which one? Flemish red and brown sours? The Trappist ales? Belgian lager? Abbey beers? Wit biers?
> 
> I’ve become enamored with the Big Muff and the variations. My plan is to purchase 4-5 Muffin boards next time I place a PedalPCB order.
> 
> I want the “Standard Triangle” circuit, the Green Russian, etc. Now that I am starting to understand how to use them, I appreciate the variations.


To be fair, all of the different muff variations have a 99% identical topology— it’s mainly just the values that differ and bring the changes in tone, and possibly a small handful of additional or missing components. With Tonebenders, the differences are on the scale of entire circuits being unrelated. It’s practically more like if someone said they’re using a muff, and you need to figure out if they mean a Big Muff, A Muff Fuzz, a Muff OD, the Germanium Muff, or an English Muff’n


----------



## Coda

Bricksnbeatles said:


> To be fair, all of the different muff variations have a 99% identical topology— it’s mainly just the values that differ and bring the changes in tone, and possibly a small handful of additional or missing components. With Tonebenders, the differences are on the scale of entire circuits being unrelated. It’s practically more like if someone said they’re using a muff, and you need to figure out if they mean a Big Muff, A Muff Fuzz, a Muff OD, the Germanium Muff, or an English Muff’n


I think the difference is that when most people say ToneBender, they are referring to a MKII…


----------



## Big Monk

Coda said:


> I think the difference is that when most people say ToneBender, they are referring to a MKII…



Yup!


----------



## Big Monk

Coda said:


> I'm thinking of adding your tone mod to it.



It’s definitely a take on the Large Beaver switch but with the Ram’s Head high and low pass resistors. 

I’m just realizing that I used 22 nF for the Boost position when I meant for that position to be 22 nF total. I should have used 18 nF so the parallel combo of 4.7 nF and the Boost cap was ~22 nF rather than ~26 nF as it is now. 

I may still do that when I swap it to the permanent enclosure.


----------



## Big Monk




----------



## Harry Klippton

That's more like it!


----------



## fig

zippety-doo-dah...look at that!


----------



## Big Monk

Many thanks to everyone here who encouraged me to do graphics and for @SYLV9ST9R and all his behind the scenes support.


----------



## Big Monk

Ported over!


----------



## caiofilipini

Looks super cool!


----------



## Bricksnbeatles

Big Monk said:


> Ported over!
> 
> View attachment 18440


That’s one classy looking fuzz pedal


----------



## Big Monk

Bricksnbeatles said:


> That’s one classy looking fuzz pedal



Thank you! (Internal Dialogue: “Did he just call my Big Muff a fuzz?!”)


----------



## Big Monk

I bought some Russian BMP knobs in my last SBE order. I smell a Green Russian coming...


----------



## Harry Klippton




----------



## Big Monk

Harry Klippton said:


> View attachment 19340



I'm excited.


----------



## Harry Klippton

Lol don't get too excited. It's still a big muff and basically sounds like a big muff


----------



## Big Monk

Harry Klippton said:


> Lol don't get too excited. It's still a big muff and basically sounds like a big muff



Fair enough. 

It is at least different enough from the Triangle/RH circuits to warrant a build.


----------



## Coda

I prefer the Civil War to the Green Russian. The difference is subtle, but there is a difference. To my ears, the CW is a bit smoother, and less boomy…


----------



## Big Monk

Coda said:


> I prefer the Civil War to the Green Russian. The difference is subtle, but there is a difference. To my ears, the CW is a bit smoother, and less boomy…



Noted!

Like the Triangle/RH, from what I've read, the Civil War and Green Russian are kissing cousins.


----------



## Coda

Big Monk said:


> Noted!
> 
> Like the Triangle/RH, from what I've read, the Civil War and Green Russian are kissing cousins.



They are a lot closer than that. There is only a 4 component difference. I built them both into the same circuit and a toggle.


----------

