Arbiter Fuzz Face Woes

[Victor Williams]

hey all, first post. I'm a real beginner to all this stuff. I just got a germanium-transistor fuzz face in the mail from a friend, hooked the thing up, and the sound comes through really really faint. it sounds fine when bypassed, but with all volumes and fuzz up and the effect engaged it sounds fuzzed, but almost silent. any advice as to what to do? thanks a lot,

VW

[Luijo]

I guess the first question would be...how skilled are you in electronics?
This could make advicing a lot easier/harder.

[Victor Williams]

not very, but if you tell me what to do, I will figure out how to do it. there's also a former electrical engineer in the house, so between the two of us, we can pull it off.

[Luijo]

The first thing to try would be the transistors. Two things to check here (best done by your buddy, I guess). Check for good transistors, sometimes a bad or incorrectly used power supply can kill trannies in a sec. Second thing to try would be bias at the collectors(assuming the are NPN) of your trannies. Most people report best results with the bias voltage at half the supply voltage.
Of course, all of this assumes you have already checked for bad cables, dead batteries, bad input/output jacks and any interconnet cable that may have come loose.
Do the pots sound scratchy when you move them? If they do they could either be dirty or you have a leaky cap in there. Go for the pot cleaning spray first.
Looking forward to your report on these first checks, good luck.

[Victor Williams]

yeah, we definitely have it isolated to something in the actual fuzz circuit itself. the signal was fine when the fuzz was bypassed, so the jacks are presumably fine. the switch is clean and crisp, and for the little that it made any difference, the pots sounded smooth. the battery is new and made a vox V847 work perfectly fine. all right, we'll check out the transistors like you said and see what happens. sucks that these are probably the problem, the "germanium sound" is the whole reason I got this thing... more later,

VW

[Luijo]

The germ transistors can be replaced and still get a very good sound. All you have to do is get the right ones and bias them properly. There a couple of places you can buy them from but Small Bear is the fav around here, very good rep AFAIK.
That's just in case it IS the transistors that are fried of course.

[petemoore]

Could be a missed ground clip a DMM lead there and test all ground points, you can also 'beep mode' test the input and output connections from jack tip through switch to circuit connections, while there test that there is no ground connections to signal path.
Test battery +/- at clip for non connection.
Take the voltages on the transistors, Q1C/Q2C should be same, about 1.2v or s.l.that, Q2C should be about 1/2v of battery supply, Q1E grounded.
Taking the transistor voltage measurements most often reveal a problem, at least a 'location, sometimes the instantaneous solution.