Powersound overdrive voltages problems

[krsdrm]

I made the Powersound overdrive and it works but not properly it's very gated and splatty. I'm pretty sure that the voltages are off but I'm not sure where to begin fixing them. Here's the voltages with and without the transistors in.

With:

Q1
1.9
1.214
.669

Q2
12.38
1.9
1.291

Q3
1.961
2.499
1.860

Without

Q1
17.76
0
0

Q2
17.97
17.76
0

Q3
17.97
3.225
0

IC100
9.36
6.117
0
2.865
-2.837
4.532
5.664
9.36


Thanks
Kris

 

[zgrav]

a quick check to see if you have an outlier transistor -- since all transistors are the same. swap them around and see if the voltages change for the readings you posted above. if you see a difference, swap them again and see if one of the three is consistently different from the other two.

if your readings are constant it will be time to start comparing your part values and pcb connections to the circuit diagram.