Mark Hammer's Muff Fuzz revisit

[geekmacdaddy]

Happy New Year  Always loved the Muff Fuzz, and came across this thread; https://www.diystompboxes.com/smfforum/index.php?topic=77456.0  so I cooked up something using Torchy's layout as a ref. It all works, but that tone control isn't doing what the tone control in the youtube does, (referenced in the thread). It's much more subtle. I have rechecked many times and believe the build to be correct as per the layout. Anyone care to take a look, or try?

Thank you

[Mark Hammer]

I suspect it appears to not be doing anything of use because the cap value for the tone control should really be 27nf, not 2n7.  With 2n7, at max treble-cut, the rolloff only begins above 5khz, which won't be particularly apparent.  Use a larger value cap, and let us know if things improve.

I will also put in a plug for tinkering with the 100k feedback resistance from Q2 to Q1's base.  Increasing the resistance introduces some glitchiness and zippery qualities.  If you're game, consider using a 3-position toggle, and a 270k resistor in place of R4.  The toggle would strap additional resistors in parallel to get 180k (270k + 470k) and 108k (270k +180k).  In the middle position (270k alone) you get max glitchiness, and the two side positions get you close to stock (108k) and more edge (180k).  You could also simply stick a 250k pot in series with the stock 100k R4 to do the same thing, but the switch takes up less room and is repeatable.

Finally, lifting the ground connection of the clipping diode pair will still yield plenty of distortion; it IS a silicon Fuzz Face, after all.  I see you are using germaniums.  Lifting those will result in a HUGE change in volume, so my own preference would be to either use silicons or even a pair of LEDs.  I gather EHX original tacked on the diodes to get some edge, while not incorporating high gain.  But if you're going to go with variable gain, the diodes don't serve much of a point, for me.

[geekmacdaddy]

Outstanding. Thank you, Sir. I do like the "woody" quality of the NOS 1N270's...part of the attraction for me...but I'll whip another one with alternative clipping, fix the value on the current build, and report back.

[geekmacdaddy]

Cap change worked like a charm. experimenting with a 3 position switch for diode selections, which will be LED, Asymetrical Silicon, and 1n270's. Just not a fan of the glitchy sound, so not going there...thanks very much for the help 

[geekmacdaddy]

check that. will try the glitch mod as well. 

[Mark Hammer]

It's not for everybody, but does offer some additional sounds.  Interacts with the gain control.

I freely confess to having stolen the idea from ZVex and the Wooly Mammoth, that uses it to good effect.  It's a clever one that surely belongs on everything using a basic Fuzz Face structure.  The nice thing is how easy it is to go back to the traditional setting.