bias adjustment on the super fuzz circuit

[mordechai]

Can anybody help me determine which transistor on the super fuzz does the "fuzzing" (a la Q2 on the fuzz face) that I could adjust via a resistor...and, pursuant to that point, which resistor serves as the bias resistor?

[R.G.]

You're not going to like this.

None of them do the fuzzing in the same way that the fuzz face works. The fuzzing is done by the back-to-back diode clippers and to some extent the full wave rectification in the almost-a-differential-pair.

[Brossman]

If you want to experiment with the (perceived) level of fuzz outa this box, why dont you try subbing different arrangements of the clipping diodes?  Or, even removing them, altogether? Try Germanium and Silicon... anything there would be worth a shot in my books.

There is also a 10k trimmer in between the Full-wave rectifier pair.  BUT, this is mainly for dialing in the octave, or rather, biasing between the two to make them as "matched" as possible - SO, not quite a gain trimmer...

Now, I'm no expert, but I would think the resistor that biases the voltage to the tranny would be the one that comes from the V+ rail...  ??

[Mark Hammer]

Like a number of similar circuits/pedals, you don't need no steeng-king diodes to get distortion.

The Superfuzz I made for myself has a 3-way toggle switch that gives me no diodes, GE diodes, or SI diodes, and there's distortion on every one of them, just more with the diodes.

[mordechai]

Mark, what is the difference in tone between the SI and Ge diodes in the circuit you built?  Is it similar to what happens when Ge diodes are used instead of Si in an overdrive unit, i.e., a "warmer" tone?

Would you advise having one Ge and one SI, or will that not work in this circuit?

[Mark Hammer]

Quite frankly, the only difference I can detect is that one is louder than the other, and reached clipping more easily than the other.

The thing is that when you have full wave rectification there is no consistent "character" to the harmonic components added.  Feed that to a diode clipping pair and the predictability of the distortion properties, based on diode-type alone, decline even more.

It's like asking if 16 year-olds are "smarter" than 12 year olds, and then taking a bunch of each, feeding them psylocibin and placing them on the Tilt-a-Whirl for a half hour. It becomes kinda hard to tell.  (Note: DO NOT try this at home or anywhere for that matter)

I think there is some value in having a diode-lift switch on the conventional Superfuzz circuit, or any variant of it (same thing for the Foxx Tone Machine), but little value in monkeying around with different diode types and more complicated switching arrangements.