Need help debugging GGG Rodent

[appliancide]

My first pedal build is giving me a little trouble.

I had it working perfectly on the breadboard. Then I designed a pretty tight stripboard layout and soldered it together. Initial troubleshooting showed that I had forgotten to connect VCC to the chip. Also missed a trace cut and had one resistor leg in the wrong place.

Fixed all of that and now I'm pretty sure everything is connected correctly.

Here's what's happening: (All part numbers are referring to the Rodent schematic at GGG.)

I feed a sine wave to the input jack and it makes it to pin three of the IC just fine. Pin six shows an amplified version of the wave that responds to distortion pot. Seems ok (I think), but the wave makes it no further. I know that R6 is fine because I replaced it to make sure. I do see the wave go through R5 though. Should it do that?

DC voltages on the IC: (1) 8.4v (2) 4.5v (3) 2.5v (6) 4.5v (7) 9v ( 4.5v

Any thoughts or advice would be greatly appreciated.

Thanks!
Paul

[anchovie]

Starting from the R6 output, check for shorts from the signal path to ground.

[appliancide]

I have a working pedal!

I didn't think to look for problems where the wave was supposed to be. I figured that since I didn't see it at that node, the problem was before that.

Build mistakes:

- No Vcc to to chip! (layout error)
- R1 was misrouted by one hole connecting it to ground instead of the voltage divider (layout error)
- Missing trace cut connected volume pot input to about 7 volts (layout error)
- Missing trace cut connected the junction of R6 and C7 to about 4.5 volts (layout error...seeing a pattern here?) Your comment helped me solve this one anchovie. Thanks!
- R9 was replaced by a jumper! (layout failure) I don't remember being drunk when I was drawing this up...
- Used "cool" smiley to represent pin 8 (troubleshooting frustration error)

Though it was a bit discouraging not having a working pedal right away, it was pretty cool to see the signal make it farther and farther into the circuit as I found and fixed the problems.

[juse]

Congrats!