# Tone Bender Mark II [BreadBoard]



## fig (Jun 24, 2021)

You may remember my janky rig from another thread, here it is with candy.
I still have a pre-flight to do so I haven't put the current to it yet. If it survives, I'll put it in a box.











if you spot a fault, please let me know.


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## fig (Jun 24, 2021)

Yeah, well...starting with R1 , and my BO wire.
I need those tape tags that are all the rave.


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## fig (Jun 24, 2021)

Nailed it! A few other changes were needed, but it will go on a 7x13 board.


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## peccary (Jun 24, 2021)

I just wanna know how many Dead concerts that scrunchie attended with you ☮️


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## fig (Jun 24, 2021)

Ahh yes, Sugar Magnolia.
_Waits backstage while I sing to you_


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## fig (Jun 24, 2021)

Those transistors remind me of 3 Lincoln impersonators in a huddle.

_rabble, rabble..mumble...mumble...1,2,3,4 SCORE!_


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## Feral Feline (Jun 24, 2021)

You've got the top-hat(s), where're the tails and spats?


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## fig (Jun 25, 2021)

Spats, wow. I remember the stench of Clorox rising from my freshly _slightly _over-bleached spats just before Contest in HS marching band.


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## fig (Jun 25, 2021)

Oh yeah thanks!


@ 72° F​Q1​Q2​Q3​GAIN60​80​119​LEAKAGE.023mA​.030mA​.033mA​

​


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## fig (Jun 25, 2021)

.Sorry, I short-handed it. Q1 would be .023mA. As @Feral Feline wrote, I need to start using the correct units and symbols.


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## fig (Jun 25, 2021)

It sounds like my electric razor against my skull so _something_ must be right (or there's an awful tear in my speaker).


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## uranium_jones (Jun 25, 2021)

I'm guessing GAIN is hfe/Beta? Where would I find "Leakage" on a data sheet/what variable do the EE's call it?


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## fig (Jun 25, 2021)

I swapped R6 for a 20K trimmer. I'll dial it closer and throw up some voltages..


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## fig (Jun 25, 2021)

Question: Aren't the gain/leakage ratios _mostly _relative between transistors (in fuzzy stuff anyway)?


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## Coda (Jun 25, 2021)

With Ge fuzz, I am of the opinion that as long as it sounds good, you are good. If you like the sound, I wouldn’t worry too much about trying to get it right on paper…


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## fig (Jun 25, 2021)

I prefer to have it set as prescribed _initially_ to know it is functioning correctly. After that, it's my ear's turn.


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## JamieJ (Jun 25, 2021)

thewintersoldier said:


> I usually worry about leakage than gain, unless a circuit needs gain in a certain range. It also depends on what part of the circuit a particular transistor is in. In the tonebender Q2 makes the quality of the fuzz. Q3 effects the sizzle and heat. To much gain and it's to trebly, not enough and it's bland. I get in range and listen with my ears and not my eyes as many people do.


We definitely need your Tonebender master class Chris!!


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## fig (Jun 25, 2021)

thewintersoldier said:


> I'm just taking wild stabs in the dark.


That's what she said.

I'm going to fine tune it with resistors after the trimmers tell me how much.


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## fig (Jun 25, 2021)

Hey...I'm here to learn, laugh, love, and rockNroll!


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## JamieJ (Jun 25, 2021)

fig said:


> Hey...I'm here to learn, laugh, love, and rockNroll!


🤣🤣🤣


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## caiofilipini (Jun 25, 2021)

I have a Seeker MKII, happy to provide bias readings as a reference if it's interesting.


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## fig (Jun 25, 2021)

Please, and thank you!


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## caiofilipini (Jun 25, 2021)

fig said:


> Please, and thank you!


I'm out of town until Sunday, but I'll do it once I'm back.


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## caiofilipini (Jun 28, 2021)

Alright, I'm back (and a little drunk) but I believe this is what my DMM is telling me about the Seeker:

Vcc=9.26V

Q1
Ve=0V (GND)
Vb=0.085V
Vc=8.05V

Q2
Ve=0V (GND)
Vb=0.097V
Vc=0.224V

Q3
Ve=0.135V
Vb=0.224V
Vc=8.18V


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## fig (Jun 28, 2021)

Thanks Caio. I'll check these against my BB as soon as I'm done with the LGSM for Chuck's tutorial. It's using the PSIO _currently_.

A little drunk? In which direction are you headed?


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## caiofilipini (Jul 2, 2021)

I just breadboarded an MKII that I really liked, and here's what I got as far as biasing and gain/leakage goes:

BATT: 8.9V // Q1c: 7.8V // Q2c: 0.37V // Q3c: 6.65V
Q1: hFE=77 / leakage=132uA
Q2: hFE=68 / leakage=22uA
Q3: hFE=106 / leakage=279uA

Here's a quick clip:

__
		https://soundcloud.com/white-mockingbird%2Fmkii-breadboard%2Fs-1V7yDPvREaz


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## JamieJ (Jul 2, 2021)

caiofilipini said:


> I just breadboarded an MKII that I really liked, and here's what I got as far as biasing and gain/leakage goes:
> 
> BATT: 8.9V // Q1c: 7.8V // Q2c: 0.37V // Q3c: 6.65V
> Q1: hFE=77 / leakage=132uA
> ...


That sounds incredible Caio!


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## caiofilipini (Jul 2, 2021)

JamieJ said:


> That sounds incredible Caio!



Thanks, @JamieJ!


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## music6000 (Jul 2, 2021)

fig said:


> You may remember my janky rig from another thread, here it is with candy.
> I still have a pre-flight to do so I haven't put the current to it yet. If it survives, I'll put it in a box.
> 
> 
> ...


They pinched those transistors from Telecasters!


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## Harry Klippton (Jul 2, 2021)

caiofilipini said:


> I just breadboarded an MKII that I really liked, and here's what I got as far as biasing and gain/leakage goes:
> 
> BATT: 8.9V // Q1c: 7.8V // Q2c: 0.37V // Q3c: 6.65V
> Q1: hFE=77 / leakage=132uA
> ...


That sounds so good, better than the mkii I built a few years ago. Maybe I should revisit it with everything I've learned from Chris


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## Harry Klippton (Jul 2, 2021)

Hey @caiofilipini what's your chain like in that clip?


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## caiofilipini (Jul 2, 2021)

Hey @Harry Klippton, good question:

Gibson SG Standard w/ SD Seth Lover pickups /
MKII breadboard /
Friedman Mini Dirty Shirley 20W head /
Torpedo Captor X (I think I had Greenback IRs) /
Focusrite Scarlett 2i2


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## Big Monk (Jul 2, 2021)

thewintersoldier said:


> That sounds  awesome. If you really wanna make it a flame thrower get the Q2 C closer to .15-.2v and Q3 C closer to 8v. That boi will catch your house on fire



There are four key points I've learned from studying the MK II topology:

1.) Biasing Q1c lower helps overall cleanup;

2.) Biasing Q3c lower exponentially in creases sustain, feedback and note bloom, but comes at a price. In this case, noise.

3.) Adding a "Pre-Gain" control at the input increases the overall versatility and character of the circuit by letting it operate in varying zones ov fuzzy overdrive, crunch, and fuzz freakout. Naturally, it also helps cleanup;

4.) Switching in a bigger output cap can put you in faux Big Muff territory.


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