Great Gig in the Sky

I put together an AMZ Q&D Compressor. I am having some difficulties and was wondering if anyone can offer some insight.

First – here is the tech page with the schematic – http://www.muzique.com/tech/2166.htm

It seems to work very well, except for the GATE pot. When the GATE pot is cranked all the way up, it works. If the GATE pot is anything less than dimed, I get horrendous feedback and squealing.

I did some voltage testing –

Q1 – 2n5457

D – 9 v
S – 5.46v
G – 4.5 v

U1 – 78LO5
1 – 5v
2 – 0v
3 – 9v

U2 – SSM2166
1 – 0v 14 – 4.95v
2 – .14v 13 – 2.25v
3 – 2.47v 12 – 0v
4 – 2.47v 11 – 4.95v
5 – 2.26v 10 – 1.42v
6 – 2.26v 9 – 4.95v
7 – 1.56v 8 – .58v

D1 – 9v

Other notes: I changed C6 to 10uf, as I play bass, and C8 to 100uf, to address any power supply hum.

If I turn the GAIN all the way down, I can back off of the GATE a bit, but it is all but unusable unless it is fully dimed.

Argh….

Q&D Compressor 1