GGG Foxx Tone debug

[Adamo]

GGG Foxx Tone with 2 foot switches

http://www.generalguitargadgets.com/pdf/ggg_ftm_lo_2fsw.pdf

The only thing 'out of the ordinary' is that I excluded the 9V battery snap. Other than that I followed everything else as described. I had some cold joints that I reflowed and all looks pretty good.

The pedal passes a clean signal just fine. When I engage the 'Bypass' switch all I get is a loud repetitive 'tapping' noise at about 160 bpm and a slight hissing in the background. No guitar sound passes through this 'noise'. If I engage the 'Octave' along with the 'Bypass' switch it continues to make the same tapping noise but the 'Octave' switch engaged by itself only produces a clean signal.

Here are my readings:

Incoming voltage from adapter is 9.33 V

Q1 (all are 3904's)
C 8.89
B 8.00
E 8.74

Q2
C 9.28
B 8.88
E 8.79

Q3
C 9.24
B 8.70
E 8.72

Q4
C 9.16
B 8.44
E 8.73

D1 (all are 1N34A's)
A 2.28
C 7.87

D2
A 8.45
C 8.46

D3
A 8.56
C 8.71

D4
A 8.71
C 8.63

Please let me know if I left out any info. This was one of my first pedal builds and it's been sitting for a while. I have since built 3 or 4 functioning pedals and I figured it was time to get this one working again. Any help or input would mean alot to me. Thanks in advance!

[cortezthekiller]

Seems like it is perhaps a grounding issue. The transistor voltages are quite off from those posted by Stuart here (3rd post down): http://archive.ampage.org/threads/1/fxgd/041958/Re_Foxx_Tone_Machine_with_a_problem-1.html

[Adamo]

yes, those voltage numbers all seem way too high. I'll look into the grounding. It did seem odd that one diode had a low reading.

[Adamo]

Bump

[peterg]

Did you check your grounding?

[duck_arse]

also, did you check your grounding?

you need to test resistance from the in/out sleeve connection to all the points on the circuit connected to ground, including the supply (I can't see the board from here), see where it is and where it isn't.