Need help with Voodoo Labs Overdrive debug

[StereoKills]

I perfed up a variation of the Voodoo Labs Overdrive with added tone control and MOSFET clippers from DIY Fever (the layout and mods by Xavier). So far, the bypass works (true bypass), but when the effect is engaged, no sound whatsoever. I do get some static when I turn the volume and tone pots.

The only modifications I made to the layout were tying R9 to ground (as the original schematic by Justin Philpott shows), subbed a LM833 for the TL082, and used a 18K resistor for R10 instead of a 19K. The diodes I'm using are the NOS germanium diodes from Small Bear, equivalent to 1N34a. Pin out for the Fairchild IRF510's was verified via the datasheet.

I've been going over the off board wiring and it seems good. I hope someone can point me in the right direction as I'm at a loss currently.

Voltage readings as follow:

Q1
S=2.99
D=3.44
G=3.44

Q2
S=3.30
D=3.05
G=3.05

IC1
P1=3.07
P2=2.91
P3=1.83
P4=0.0
P5=3.08
P6=2.48
P7=2.55
P8=7.06

D1
A=3.31
K=3.34

D2
A=3.00
K=2.96

Link to the layout .diy file:
http://www.diy-fever.com/layout_counter.php?layout_id=213&ip=67.244.50.78&file_name=voodoo_modded_perf.diy

Link to the original schematic by Justin Philpott (tone control and mosfet clippers not included):
http://www.freeinfosociety.com/electronics/schemview.php?id=1208


Many thanks

[solderman]

Try to "probe" it. from the IN and trough the signal chain. The place the sound stops is the place to look for errors.
BTW pin 7 shuld be around 9V
check your PSU.

[StereoKills]

The 9v battery I was using was a little aged, although new in the box and was a bit less than optimal voltage. I think I can bring it in to work tomorrow and hook it up to the function generator and the oscilloscope to probe it. Is it a problem that one one of the IRF510's has a higher voltage on source than drain and gate, and the other FET has a lower voltage on source?

[solderman]

The 9v battery I was using was a little aged, although new in the box and was a bit less than optimal voltage. I think I can bring it in to work tomorrow and hook it up to the function generator and the oscilloscope to probe it. Is it a problem that one one of the IRF510's has a higher voltage on source than drain and gate, and the other FET has a lower voltage on source?

not as long as they are on defferent sides of the Vb+ one side shuld be Vb+

[Barcode80]

you almost certainly have some dc voltage on your pots, so check that. that could also explain the odd voltages.

[StereoKills]

Ok. a EE coworker of mine and I used a signal generator and scope yesterday and found the culprit was a bad IC. Popped in a new one and presto: sound and distortion!

Two more things I am having issue with though. After plucking a note, in the background of the distortion, you can hear some sort of artifact or something. Best way I can describe it is an electronic sounding sizzle or rattle that builds in volume and then cuts off abruptly. zzzZZZZTT! Also, the gain pot has max gain when turned fully CCW, so I figured I had the pot wired backwards, but after rotating the pot about 10% CW, the gain drops down to nothing and the clean tone coming out is greatly reduced.

Thanks!

[StereoKills]

Bump for any ideas?