Troubleshooting fuzz. Just hiss for fuzz and mute in bypass

[Snufkinoob]

So I've built two Germanium FY-2 fuzz circuits. One works fine, the other doesn't.

There is no bypassed tone at all, and when the fuzz is engaged, it just hisses. The volume pot seems to work in that the hiss gets louder.

Odd thing is that I've compared the voltages, and both circuits are reading the same!
I've tried a different battery, clip and foot switch but it's still the same. I was thinking it could be a dodgy jack but they are connecting fine. Same goes for my guitar and amp leads, all fine.

So what's a likely cause of the problem? Grounding issue? Dodgy wire connection somewhere? Broken component that somehow still allows for correct V readings? Bad solder joint somewhere off the board? (Though I've gone over it, fixed a couple of potentially weak solder points already)

Something stupidly obvious



FWIW here's the readings...

[TGP39]

Usually when a pedal doesn't get a bypass signal, something was wired incorrectly. Lucky for you there is a working build you can compare to.  Take a look at how the guitar signal would flow when the pedal is in bypass, starting at the input Jack.  Make sure the circuit is properly grounded. If you are testing the circuit outside of the box, both the input and output jacks need to be properly grounded.  I'm sure it's something small. Take another good look at your wiring.

Steve.

[duck_arse]

check for continuity from input tip to output tip, work the switch, see what happens. then check continuity from tip in to board in, then same for output end. it seems your circuit has diagnosed a bug in the externals for you.

[duck_arse]

are you using a double pole or a triple pole for bypass? if triple, is there a chance you've rotated the switch by 90^o?

[JerS]

I would look at the input wiring. Since you are getting some hiss on output - it tells me that the guitar signal is not getting to the circuit.

[Snufkinoob]

Thanks for the replies. Will be doing a thorough debugging soon, as I have a few circuits to go through. FWIW, it's a DPDT switch.