Fuzzier Si Fuzz Face?

[Drewmeyer]

So I built a silicon fuzz face from a pigeonfx kit (pigeonfx.com) and I've got it pretty well tuned up with the bias and all, but it's still not sounding quite like I want it to. Right now it has a really torn-speaker fuzz kind of sound and at higher registers the tone is weak and the sustain is pretty poor, with notes sounding like they are choking out. Ultimately I'm looking to try and achieve a fatter creamier and more sustainy fuzz, without losing the trademark bite of the silicon trannies (otherwise I would just switch to germanium). Right now I've got a Q1 with a gain of 200 and a Q2 with a gain of 270. The biases are as such:
Q1:
C: 1.4
B: 0.6
E: 0.0

Q2
C: 4.8
B: 1.4
E: 0.7
Anyone have any tips for how to achieve the sound I want? I can provide more information if necessary. Thanks!

[Buzz]

Hi.

I can't really help you tweak that particular circuit, but I have run into your problem.

I have built a couple of Si FF's, and wasn't very interested in using them.

A more useable version is GGG's Boutique 70's version. http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_b70.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

The mid pot gives a wider range of sounds than you might expect. It also has a 1N34A clipping diode at the end. It still has the Si sound though, I think that diode might just be a mojo clipper.

Sounds great on a strat with neck pup or middle plus neck.

Trannies used were good old bog standard 2N3904.

[smallbearelec]

Try lower-gain transistors. They don't have to be anything exotic.

https://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

Regards
SD

[LucifersTrip]

Poor sustain & notes sounding like they are choking out seems unusual....that's not what you should be getting, especially since your voltages aren't bad.

There's probably a problem somewhere if your description is accurate.

I prefer lower gain transistors for a FF, like SD suggests. The sound won't be as mushy & synthy, but that doesn't seem like your problem.

Have you tried small caps (50-200pf) across Q1 and/or Q2 B-C's?

[col]

Try different transistors in various combinations but the advice above is good. Use low gain for a better sound. I got good results with BC109As and some very low gain old ones (less than 100). Alternatively swap the other components for the values of the Orange Sunshine fuzz. I have never built one that sounded crap with any transistors, unlike some Si FFs.

Col

[davidallancole]

Do you have your amp turned up enough?  I find these fuzz faces sound fat and smooth when the amp is distorting a little but sounds like crap when your playing in your bedroom.

[Drewmeyer]

Poor sustain & notes sounding like they are choking out seems unusual....that's not what you should be getting, especially since your voltages aren't bad.

There's probably a problem somewhere if your description is accurate.

I prefer lower gain transistors for a FF, like SD suggests. The sound won't be as mushy & synthy, but that doesn't seem like your problem.

Have you tried small caps (50-200pf) across Q1 and/or Q2 B-C's?

Thanks for all the replies and help, guys! I tried this since it was particularly easy to test out, and it worked great! Cleaned up some of the high end fizzle and helped achieve a much more desirable tone. Thanks again for the help, this forum never fails to give great info!

[pinkjimiphoton]

increase the voltage some. sounds to me like you may be starving those particular transistors a little too much... shoot for a collector voltage closer to 5-even 6 volts on q1... don't worry about the voltage being 4.5v use your ears and find the "sweet spot"... your gain range should be fine with proper biasing for a silicon face.

[Quackzed]

+1 higher collector voltage on q1, so make the collector resistor smaller, try half the value and measure, shoot for anything from 4.5 to 6 or even 7v ... this should lose a bit of the torn speaker sound and gating, and make it a bit smoother susstainier and more compressed. better yet use a pot or trimmer with the middle lug and 3rd lug connected (say a 50k pot or even a 20k for those trannies) and just dial it where you like it, leave it in to have options later or replase your magic resistance with a resistor of closest value. fuzzes need a little tlc in the biasing to really shine.

[pinkjimiphoton]

+1 higher collector voltage on q1, so make the collector resistor smaller, try half the value and measure, shoot for anything from 4.5 to 6 or even 7v ... this should lose a bit of the torn speaker sound and gating, and make it a bit smoother susstainier and more compressed. better yet use a pot or trimmer with the middle lug and 3rd lug connected (say a 50k pot or even a 20k for those trannies) and just dial it where you like it, leave it in to have options later or replase your magic resistance with a resistor of closest value. fuzzes need a little tlc in the biasing to really shine.

+2!! lol

[LucifersTrip]

-2

are you guys talking about Q1 or Q2?

[Quackzed]

q1 in this case, but both really... in this particular case q1 looks starved.

[LucifersTrip]

Q1 C voltage for a FF is usually right around 1.4V.  That's perfectly normal and is definitely not starved.

If you set it 4.5V+ it's not going to sound like a Fuzz Face.  Additionally, you'd have to massively alter the biasing resistors on Q2 to get Q2C voltages in the 4.5-6V range.

Here's some working voltages from standard si FF (last page):
http://www.generalguitargadgets.com/pdf/ggg_ff5_instruct.pdf

Additionally, for a ge Fuzz Face, Q1C voltages average even lower, around .6V

[Quackzed]

Q1 C voltage for a FF is usually right around 1.4V.  That's perfectly normal and is definitely not starved.

thats weird, i thought i remembered q1 being close to 4.5v... must have been thinking of q2. 
but your right, q1 looks fine.