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FuzzFactory upgraded clone problem

PostPosted: 09 Feb 2013, 16:35
by Zokk

I've just build a FF clone using the Madbean schematic (Zombii) with one interesting mod and I have a weird loud pop problem.
Yeah it sounds like a "first build" problem, but really it is not the case :wink:

The main mod I've added is an expression pedal input to control the Stab, it's wired onto a switched jack and a DPDT stop switch. I've wired it in a way that when nothing is plugged in the jack the Stab pot still have control no matter how the stomp status is.
There's also a LED for this switch...

First the bypass switch was wired straight "true bypass", with nothing more, I mean no pulldown res or something like that... The loud pop occured only when the bypass switch was used but the manual/expression switch was dead silent.
As this pop was a big problem, I've tried to find a solution:
added a 1Mohm pulldown on the output jack > no result
added a 470Kohm pulldown on the circuit input (not the jack) > no result
changed the TB wiring for a input circuit ground version > now the pop occurs with both stompswitches
added a res+cap on the bypass led > no result
added a emitter-follower circuit (based on a 2N2222 tranny) on the circuit output > weird bypass problems and still loud pop with both switches
changed all the caps > no result

I've used "high gain" russian germs, 90hFe and 134hFe...
And the pops occur with and without an expression pedal plugged in.

Now I really don't know what to do... I'm thinking to remove the full 3PDT and replace it with a Boss-like bypass but I don't even know if this will solve the problem.

Please could someone give me an idea?

Thanks a lot


ps: the layout is pretty messy with the ground wiring, this is a bit more efficient on the real thing as I've cleaned some long wires when soldering.

Re: FuzzFactory upgraded clone problem

PostPosted: 06 Mar 2013, 11:37
by Zokk
I've solved the pop problem!
I had to change the bypass switch (got some nice glod plated from Mammoth), cleaned the ground wiring a bit, and I've used the wiring diagram from another layout (which is a bit more simple than the one I've previously used).
Now I can hear a pop when the manual/expression switch is depressed, but only if the volume and tone controls of the guitar are set to zero... so it's fine as I barely play guitar with these controls off :wink: