Big Muff Tone Stack Talk

[morange]

Please, come sit. Let us talk together now, very simply, as men. ILF, talk.
There was once a dream that was Big Muff. You could only whisper it. Anything more than a whisper and it would vanish... it was so fragile. And I fear that it will not survive the winter. ILF, let us whisper now, together, you and l. You have a Big Muff. Tell me about your tone stack.

http://www.duncanamps.com/tsc/ Duncan Tone Stack calculator
http://www.kitrae.net/music/Big_Muff_Mods_and_Tweaks_Page.html The eternal golden reference
http://www.muzique.com/lab/tone3.htm AMZ mods, Mids control for example, slight variation below

NSFW: show

[youtube]http://www.youtube.com/watch?v=LaY7Y2TrTMk[/youtube]

Violet Ram's Head


R2 is 8.2k in series with 25k audio pot (use resistance between lugs 1-2) to achieve a mids control, Violet scoop to flat response


Green Russian


In these next ones, I just rolled the tone pot all the way treble to make it look like a fixed resistor in a Superfuzz-style tone stack

Superfuzz compared to Violet scoop


Bee-Baa compared to Violet scoop

[crochambeau]

I've only got one Big Muff (a triangle) and have never been blown away by the swing of the tone knob. Though, due to the age of it I tolerate my suffering instead of cutting anything.

[eatyourguitar]

I know there is a difference between ltspice, dtsc, and the actual build with these custom values. Just try and compare with LTspice using a 2n5088. The graphs do not match. My best advise is to go back and swap parts after you test out the new build. The tone stack calculator will give you hints on what will happen. Try it.

[SoaringTortoise]

Too muffled on one end, too thin on the other, and uninspiring in between.

[digi2t]

I've been using the mid-boost mod on my builds. Long story short, it works really well for me. I have it set up so it scoops fairly close to a standard BMP, but I can raise it to a bit above flat. I don't have the Duncan Tone Stack calculator snap shots, but here's a schematic of one of my builds using the mid boost control.

[morange]

How's it sound with the germanium diodes and transistors? And does the volume get loud enough?

[eatyourguitar]

I tried silicon PNP BC557 or something like that with 1N4148. I used the flat BMP tonestack you can find on the internet. turned it CCW and used it on bass. it shakes the house. only regrets are that the tone knob is only good in one position and the pedal is only good on bass. it was later that I figured out all the secrets of the muff. when you are sitting there for hours running simulation after simulation, have a chart or text handy with the frequencies of the notes of a guitar. 88Hz for example is low E. measure your total attenuation (Db loss) at the lowest point on the graph, unless it is out of the range of the guitar. anything that is -12Db scoop or even rolloff at 88Hz is too much. this kind of shit never works in reality so you can cut it right out. these are your restrictions for a new happy muff. there is one exception to the rule however and that is with super narrow band scoops. you can have -24db as long as the Q factor is less than a total octave. it will have that sweet 80's sound when you do sweep picking scales. it changes your sound when you hit that one note that is dialed in on the tone knob.

[eatyourguitar]

How's it sound with the germanium diodes and transistors? And does the volume get loud enough?

with germanium clipping diodes you can't really appreciate the sound they offer unless you have the entire muff setup for low gain. you need to keep the emitter resistors or you are just wasting time with fancy clipping options. I have never used germanium transistors in a muff but I guess if you do then you are already pretty low gain and germanium diodes (or your scrap busted leaky PNP) will do fine. too much gain and not enough headroom will always sound like a boring metal muff or a double muff only not as cool as either of them. I would worry about attenuating a low volume signal too much through the tone stack if Q3 has germanium clipping. increase the resistance to ground through the tonestack. first through the ground resistor then through the other one. this will cut down on your volume loss.

[digi2t]

How's it sound with the germanium diodes and transistors? And does the volume get loud enough?

I did a lot of breadboarding with all an ge version, but in the end, a hybrid version was the best. Using all germanium transistors was tough, since any leakage in a particular stage gets amplified by the next stage. It makes for quite a hissy beast. Using germanium transistors in the clipping stages only helped tame the hiss, yet yields a nice fuzz. Not as harsh as an all silicon BMP, with better interaction with the guitar controls. Volume is fine, mine runs unity at around 2 o'clock on the volume control, so there's enough left over to boost if need be. Here is the updated schematic;



It's a rounder sound. On my Tourmaster, good, full fuzz on a clean channel, and really thick and meaty on an overdrive channel. Excellent singing sustain when used with an overdrive channel. I prefer it to my silicon versions.

Final build pic;



And mid boost curves (turns out I did have screen shots after all);