A simple Muff mod

[Mark Hammer]

A friend had requested I make him a clone of his big-box black Russian BMP.  After studying the schematic I realized that one of the differences between the Black/Green Russian and more familiar "standard" Muffs, I realized the tonestack values moved the scoop upwards in the spectrum, and also made it a little narrower.  But, in tandem with the lower gain of the Russian clipping stages, it yields a nice sound.

I was inspired to change the values on a Muff I had built, and realized that a DPST toggle could easily go between Russian and "domestic" tonestack.  The standard stack uses 39k resistors.  Strapping a 51k resistor in parallel with each 39k resistor gives a combined parallel value of 22k - what the Russian stack uses.

Switching back and forth between the two tonestacks does not yield any sort of day/night difference.  But when the friend was over today to pick up his clone, I demoed the switch on mine for him, and he identified the "Russian" position as nailing the sound of his pedal.

[Vivek]

Wow great idea !

We could plot these two variants at https://www.guitarscience.net/tsc/bigmuff.htm#RIN=1k&R1=39k&R2=22k&RM=100k&RL=1M&C1=4n&C2=10n&RM_pot=Linear

and visually see the differences.

[Vivek]

Normally, the Russian Tonestack is better stacked and has more interesting curves than the domestic variety.

[iainpunk]

interesting, i wasnt even aware that there was difference between big muff tonestacks. i just assumed that it was only the bias network values to accommodate the different transistors used through the years.'

cheers

[mdcmdcmdc]

I'm sure they've been cataloged elsewhere as well, but Coda has a nice list of all the changes to the tone stack between variants: https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html

[Mark Hammer]

interesting, i wasnt even aware that there was difference between big muff tonestacks. i just assumed that it was only the bias network values to accommodate the different transistors used through the years.'

cheers

Yeah, like yourself, I was distracted by the emitter and collector resistor values, and never thought to look at the tonestack.

The "bass" side of the tonestack has a wider bandwidth than the more standard BMP values.  Combined with the reduced gain, it almost achieves an overdrive sound when you dial back the Sustain, and roll back the Tone from the midpoint.

[andy-h-h]

I'm sure they've been cataloged elsewhere as well, but Coda has a nice list of all the changes to the tone stack between variants: https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html

I mapped quite a few BMP values out here.   https://vero-p2p.blogspot.com/2021/01/big-muff-electro-harmonix-component.html

[Vivek]

I'm sure they've been cataloged elsewhere as well, but Coda has a nice list of all the changes to the tone stack between variants: https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html

I mapped quite a few BMP values out here.   https://vero-p2p.blogspot.com/2021/01/big-muff-electro-harmonix-component.html

That's really great

It would be so nice if you posted links to TSC IN THE WEB with those Muff values

[davent]

Big Muff tone stack calculator, there are a bunch of others, based around Duncans calculator.

http://www.guitarscience.net/tsc/bigmuff.htm#RIN=1k&R1=39k&R2=22k&RM=100k&RL=1M&C1=4n&C2=10n&RM_pot=Linear

[andy-h-h]

I'm sure they've been cataloged elsewhere as well, but Coda has a nice list of all the changes to the tone stack between variants: https://www.coda-effects.com/p/big-muff-tonestack-dealing-with-mids.html

I mapped quite a few BMP values out here.   https://vero-p2p.blogspot.com/2021/01/big-muff-electro-harmonix-component.html

That's really great

It would be so nice if you posted links to TSC IN THE WEB with those Muff values

Until now I didn't know that was possible.  Good idea 

[Steben]

Great!

Now can we combine that with a mid control? 

[amz-fx]

Now can we combine that with a mid control? 

AMZ Presence Control from almost 20 years ago, which has impact on the mids of the tone control.

Also interesting is this variation.

Best regards, Jack

[iainpunk]

how about this, combined with a mid scoop control, like in the Mark Hammer version of the FY-2.
you might want to change the values of the filters in the feedback loop, since these were optimised for a wah-like effect. the normal TSC works, you just have to flip the graph upside down.





cheers

[Mark Hammer]

My first thought as well.  The uninitiated should note that this is not the same as an explicit midrange cut/boost control. 

The Muff tonestack normally divides the signal into higher and lower bands, with some limited degree of overlap between them.  The less overlap, the bigger/wider a midscoop.  Conversely, the more overlap, the more mids pass through safely via the highpass AND lowpass sections, resulting in the rough equivalent of a mid-boost.  Technically, it's NOT a midboost, just much less of a mid-attenuation.  Six of one, half-dozen of the other, eh?  Jack's mods do a nice job of providing tonal flexibility without a major redesign of the pedal.

And, do note that where the overlap happens sets the frequency range where the apparent boost will occur.

Regards right back at ya, fella. 

[Mark Hammer]

RE: FY-2 circuit

I used what I had at the time.  Realistically, 2-5k is more than enough for the Scoop control.  Save the 50k  for another application.

[Steben]

Now can we combine that with a mid control? 

AMZ Presence Control from almost 20 years ago, which has impact on the mids of the tone control.

Also interesting is this variation.

Best regards, Jack

it was somewhat rhetorical
Version 2 is clearly a born pre-dirt / boost option