overdrive problem

[Marcos - Munky]

I built a overdrive with a single opamp, and works fine. But when I moved it to a enclosure, it stopped to work. I got a noise instead of the overdrive and the clean signal, and when the signal is "clean", the LED is on and I can control it with the pots. When the "effect is on", I got a "distortion with feedback loop" sound, but with low volume and without the guitar sound. I checked, but there aren't any connections between the input and output to create the loop. I believe this is a ground problem, because this happened when I connected a wire between the jacks and ground. Originally, it was only one jack connected to ground, because I was using a aluminium enclosure,  but I needed to connect both jacks, because I moved it to a plastic enclosure. Anybody can help me?

[mikeb]

Measure the voltages at the V+ pin of the opamp (pin 8 ), the ground pin (pin 4 ), and also the voltages on the other pins (for example, likely there is one that has a bias voltage of - say - ~4.5V) .... let us know what you find. There might be a short somewhere or something might have got messed up when you made the transfer of the circuit. Another thing to do it to take it out again, see if it works .... no doubt it will be a simple fix when you find it.

Mike

PS measure the voltages relative to the case of the effect!

[Marcos - Munky]

I will try.

[Marcos - Munky]

I found the problem. I think I blew the transistor that I used in the bypass circuit that I used (the Joe Davisson's one). I changed the circuit to a new one and now it working.