UGLYFACE, where`s the fuzz?

[GREEN FUZ]

So I`ve built the Uglyface using mydementia`s PCB layout. Housed in a Wah enclosure. Homemade optoisolator. It seems to work up to a point. Granted it`s an unruly beast but going through past threads this seems par for the course. Tons of oscillation, lasers, sirens, belches etc. Excellent...

Problem is I`m not getting much of the fuzz itself. With the threshhold up maybe a third I can faintly hear the guitar signal with a bit of fuzz. It seems to be at a very narrow point in the pot travel just before it begins to self-oscillate, and very weak. I`ve checked connections and voltages measure full at pins 6 + 8 of the chips (LM386N-1 + 7555CN ).

I`ve used all the exact value caps and resistors called for, without any mods. I had to use a 4.7lin pot with a 10k resistor across lugs 1 + 3 for the sensitivity as I didn`t have a 1k.

I`ve been trying to debug for a while now, reading my way through as many threads as possible. I will carry on but maybe someone out there has a quick answer to remedy or explain this problem.

I`ve just reread this and I wonder whether there is any point in that 10k resistor. Probably not as it didn`t make much difference.

[doug deeper]

was that pot 4.7 ohms? or 4.7k ohms???

[doug deeper]

also gotta love the green fuz!

[GREEN FUZ]

4.7k

[smnm]

also gotta love the green fuz!

here you go bay-beh, you bettarun-we're-the-green-fuz 

[edit - sorry I've got nothing to add but I love that record, and the weekend starts here]

[GREEN FUZ]

It`s always in the last place you look.

I should probably just let this thread lie but as a lesson to future DIYers I`ll let you know that I`d reversed the input and ground leads from the input jack. Now it sounds the way it`s meant to.

Oddly enough the fix has taken away most of the crazy oscillation but I think that might be down to the optoisolator. It seems to suggest that there might be a few more sounds lurking in this circuit so I`m going to experiment a bit more with it.

Thanks to the Green Fuz fans without whom this thread would have been a lot shorter.