A "Fuzz" with a "Face"

[HTH]

also, I've found that lower gain transistors works best for a Fuzz Face. additionally, set the amp so it's breaking up and the Fuzz Face will send it into orbit. if the amp is set clean, your fuzz will sound too weak.

I've build an NPN version of a Fuzz Face before with BC109s and also with 2N3904s. The BC109s are the classic silicon FF tone like Band Of Gypsies while the 2N3904s are much less gainy and closer to the old germanium tone.

I seem to recall that the most important transistor in getting the FF to sound good was the 2nd one. I was using a 2N3904 (or 2N3906 if its a PNP version) for the first transistor with a germanium transistor for Q2.

Instead of connecting Q1's emitter straight to ground, a small resistor up to around 470R works well (credit where its due - I got this idea from Joe Gagan's NVN pedals back when he was an Ampage regular in the early 2000s).

Its a circuit with the most mileage of any I've messed with - hence I still occasionally mess with it more than ten years on.

[Robert M. Martinelli]

....I've build an NPN version of a Fuzz Face before with BC109s and also with 2N3904s. The BC109s are the classic silicon FF tone like Band Of Gypsies while the 2N3904s are much less gainy and closer to the old germanium tone.

Instead of connecting Q1's emitter straight to ground, a small resistor up to around 470R works well (credit where its due - I got this idea from Joe Gagan's NVN pedals back when he was an Ampage regular in the early 2000s).

Its a circuit with the most mileage of any I've messed with - hence I still occasionally mess with it more than ten years on.

BC109s are a good choice for NPN FFs, but, since FFs seem to sound best with low/medium gain BJTs, it's wise to choose BC109s with the "a" suffix. (The BC109 family is divided into three groups, each one falling into a gain range. AFAICR The "c" family has a gain of 250 and more, the "b" family gain falls between 130 and 250, and the "a" family has a gain below 130).

Putting a small resistor between Q1's emitter and GND as per HTH's advice introduces some NFB, resulting in an overall gain reduction, so it could be useful to put a 470 Ohm trimmer (connected as a variable resistor) in its place, adjust it to taste, then put in a fixed resistor of the same value.

In spite of its simplicity, the FF is very rewarding in terms of tone, very fun to mess with and very didactic, as tweaking it can teach a lot about what's going on along the signal path.

Good luck with your builds!

Best regards

Bob

[Shea]

Thanks HTH & Bob