Rediscovered Pink Floyd and the Silicon Fuzz Face...

[Big Monk]

Title says it all. I've recently been listening to Meddle, Live at Pompeii, Dark Side of the Moon and Wish You Were Here. This prompted me to relearn how to use my delay pedal and breadboard a Silicon Fuzz Face.

I started with a bog standard Fuzz Face and picked some of the Amperex A115 NPN units I have a ton of. I knew most of the Fuzz on the records I describe revolves around the Dallas Arbiter Fuzz Face with BC108s, but knowing my Les Paul would likely hit the Fuzz Face hard, I figured gains in the BC108 range would not make me happy.

So I settled on Q1 = 93 and Q2 = 175. I kept the 33k Q1 collector resistor, the 470/8.2k Q2 string but put a 10k Trim in series with the 8.2k for bias.

I tweaked the frequency response for humbuckers by dropping the input cap to 0.22 uf ala the Axis Face and dropped the Emitter cap to 6.2 uf.

I dropped the Volume control to 250k and the Fuzz control is 1kC.

I really like the tone. Cleans up very well and has a good midrange grunt full up.

For those out there using a Fuzz Face with humbuckers, any favorites for NPN Silicon transistors? Gain ranges?

[bbr6704]

Still trying to find the best ones to my ears and taste... Sorry.

And still trying to make a FF circuit work properly. It's the first time I have such hard times to eliminate unwanted noises (even if I have build several different pedals before without big issues).

[dennism]

I've had good luck with 2N4123 and KSP42, both silicon NPN in a similar gain range as you quoted.   Also, if the circuit is still misbehaving, I've also had good luck putting a small (~47pf) cap across C-B.

[anotherjim]

If the noise is only too much at maximum fuzz (because all negative feedback disappears then) you can try adding a series resistor. Many opinions on where is best to fit it, but on a built example, the easiest might be right to the pot lug. Might only need 100R to do it. Other ideas put it in Q1 or Q2 emitters or both.