Carcass build - very low volume output, strange behavior

[inflatablerobot]

Welp, I'm a little embarrassed to ask but I've run out of ideas. Any help here would be most appreciated.

The output is audible though very low, there is some distortion that sounds like the clipping diodes but nothing that sounds like fuzz. The Before knob (B100k) and the Output knob (A100k) both have no effect on the sound whatsoever. When the After knob (C100K) or the Hi Cut knob (A5k) are brought down from full the signal disappears pretty quickly, and both seem to effect the sound in the same way.

I did change a couple resistor values, from 510k to 470k ohms for R1 which should barely change the cutoff frequency for that first RC filter. I also changed R7 to 10k from 9k1, as that was what I had available. I doubt that is the issue though.

Please excuse the flux everywhere, I've been taking things on and off this board all day.

Thanks,

 

[Coda]

What did you use for the transistors?

 

[fig]

It appears your IN/OUT jacks are wired incorrectly.

The GND should be connected to the sleeve, which is the angled connector.

 

[inflatablerobot]

Thank you for your responses.

Other than the two resistor values I mentioned above, all components are as listed in the BOM. Including the five 2N5089 transistors, which I ordered through Mouser so I would assume they aren't fakes.

I have checked the input and output jacks for continuity and the sleeves are wired to ground. The pedal passes sound through when bypassed.

 

[fig]

Interesting. I've never seen that type of jack that did not have the sleeve connection on the angled face of the casing.

I'm not familiar with those resistor color bands either. My 4-band calc shows your 220KΩ as 220Ω (red-red-brown-gold?).

Anyway, I hope you get it working. Looks like a cool fuzz.

 

[inflatablerobot]

Interesting. I've never seen that type of jack that did not have the sleeve connection on the angled face of the casing.

I'm not familiar with those resistor color bands either. My 4-band calc shows your 220KΩ as 220Ω (red-red-brown-gold?).

Anyway, I hope you get it working. Looks like a cool fuzz.

Ah, keen eye! I just probed that 220K (R14) and it is in fact missing the K. I had actually probed that earlier but failed to notice the lack of a K on the reading.

That 220R with a 1M form a voltage divider that brings 9v down to 0.002v when it should be 1.8V. Not much for the transistor to work with. Jeez, I'm surprised I can hear anything at all.

Fig, I really appreciate your help. You are a saint. Hopefully I'll have some time this week to replace that resistor and report back. I'll prob rewire the grounds on the jacks to the angles while I'm at it as that seems to be best practice. With any luck I'll have a fuzz that actually fuzzes.

 

[fig]

It’s an easy mistake to make. Glad I could help. FYI - there are four of those 220K resistors you’ll want to swap.