GGG Dist - wrong voltages at ic

[Johnbroadb]

Hi,

I built the GGG Dist. No sound when the pedal is engaged, i am getting 9v to the correct pin on the ic but all the others are incorrect.
I also used the audio probe and found that i would get no audio after C3, i replaced the cap 3 times and the same problem still occurs.
Any suggestions?

Thanks

John

[PRR]

the GGG Dist

I think GGG has more than one 'dist'?

Might need more information to get useful comments.

[Johnbroadb]

Ahhh sorry, it's the DOD 250.
I read in the guide that "the lm741 chip is integral to the DOD 250"
For some reason I was given a 323 chip in the kit. So I bought a 741 and put it in and it works intermittently. I think I have a short somewhere now.

Thanks

[duck_arse]

well, I went and looked. the "dod 250 overdrive" has no C3 shown on the circuit diagram.

the c3 is 2n2 to ground on the "dod 250 overdrive (grey version)", which would limit radio signal pickup (and it has no c5). stop replacing that cap, you can even leave it off until the rest of the circuit works. check your voltage at the junction of r2/r3/r4. it should be half your battery voltage. the voltage at pin 3 on the 741 should be very, very close to this same voltage.

probably best to go and follow the http://www.diystompboxes.com/smfforum/index.php?topic=29816.0 instructions, then we can all know what we are doing.