"Fuzz Face" improvements ?

[MartyMart]

A friend has given me his "Roger Mayer classic fuzz" re-issue to have a look at.
It sounds "thin" and "farty" and not very good at all, so I'm just wondering if this is a case of "new AC128's" that are not matched too well, or if there are some improvements I can make other than "bias" or better trannies ??
Here's two pictures :
http://www.pbase.com/image/40086943
http://www.pbase.com/image/40086968

Anyone have one/built one with some advice, I'd like to help him out ?

Thanks,
Marty.

[MartyMart]

OK, just solved the problem - thats good for me to learn more about FF's!
Bias pot was a bit "off" and I changed the 10n input cap to a 68n.
I now have a "Fuller" sounding Fuzz, I may put the 10n from input jack to ground, just to roll off a bit of "fizz"  

I think he will prefer it now, time for me to build one . . . . .

EDIT :  10n was too much, went with a 2n2 which was perfect to remove a touch of "FIZZZZZ"  Great sounding Fuzz now !!

Marty.

[Fret Wire]

Marty, do you mean the .01uf (10n) output cap? The input cap should be the standard 2.2uf. At least they have a trimmer now for Q2's collector. The older ones didn't. I have one of the originals when Guitar Galaxy (NYC) was the distributor. It has BEL AC128's in it. Sounded great when new, and still sounds good. Never thin or fizzy. The trannys are getting tired, the voltages on Q1 are still spot on, Q2's collector has dropped to 3.75v. He biased it with 16k on Q2's collector, and 27k on Q1. I should rebias it and replace the electro's, but as long as it sounds good, I'll leave it as is. Easy enough to clone. Once you're done with the biasing, the Mayer mods are just the 1k output resistor, and 2.2k fuzz pot. It does make a noticeable difference over the standard Dallas sound.

[MartyMart]

Marty, do you mean the .01uf (10n) output cap? The input cap should be the standard 2.2uf.

Sorry for the confusion!
What I mean is that I changed the 10n output cap to a 68n, then tried the 10n I had removed from input jack to ground, that was too much roll off so went with a 2n2 . . . .
The "input" cap is still 2.2uf  

Sounds wonderful now !!
Thanks Fret,
heres a modded photo :
http://www.pbase.com/image/40091637
Marty.

[petemoore]

MM, I use some kinda cap to ground, didn't used to.
 It's alot easier for me to tune the amp to a FF with some LP Filter cap[s on it.
 I'm using a .001uf at the input and a .0047uf Q2C to ground, I love the sound of that NPN Si FF...works great univibed, alone...I don't have to reset the amp to use say a Booster or alternative Distorter/booster.
 Could be just 'my amp 'n stuff, that's the way I'm liking my FF's these days.

[brett]

Hi all.
A cap parallel with the 330/470 ohm resistor also removes fizz.  I use a 0.1uF cap in silicon fuzzfaces.
Phillip B uses this mod in his axis fuzz.
cheers

[Alpha579]

i also like to put a 220pf (in silicon) or 100pf (ge) from Q2's collecter to its base, makes it smoother and less 'fizz'...