Thumb Sucker Not Working

nate_noise

New member
Hello Rock n Rollers,

Just finished building the Thumb Sucker Compressor and it doesn't turn on, no signal is coming through whether the effect is bypassed or engaged. I tried beginning to check continuity through the signal path with a digital multimeter (I'm a newb in this realm). Once I got to D3 and D4 (diffused red LEDs) in the signal path my DMM stopped beeping for continuity and instead the LED's light up (I can alternate which one lights up depending on if I swap the negative and positive probe of my DMM, the effect is not plugged in, LEDs must be pulling some power from the DMM probes).

Is that normal or is something weird going on here?
Also I detected continuity from the input jack to output jack when the effect is bypassed, so why might no signal be going through to the amp?

Should be noted I changed a few cap values for bass guitar. (C3=10n, C5=2.2u, C6=2.2u, I also used a 2N5087 at Q1.
I'm also using jacks I haven't used in a lot of other builds, ACJS-MV-3 and ACJM-MV-2 as per this datasheet

See attached pics.
Thank you in advance :)
 

Attachments

  • 2023-08-15-15.04.49.jpg
    2023-08-15-15.04.49.jpg
    449.8 KB · Views: 16
  • 2023-08-15-15.04.57.jpg
    2023-08-15-15.04.57.jpg
    438.5 KB · Views: 16
  • 2023-08-15-15.05.12.jpg
    2023-08-15-15.05.12.jpg
    437.8 KB · Views: 16
If you've got no sound either engaged or in bypass, then start looking at your offboard wiring. The stomp switch looks ok, which means the next spot to check are your jacks. Are they wired correctly? Use your DMM to confirm which pin is the hot signal.
 
If you've got no sound either engaged or in bypass, then start looking at your offboard wiring. The stomp switch looks ok, which means the next spot to check are your jacks. Are they wired correctly? Use your DMM to confirm which pin is the hot signal.
good call - just looked more closely at the schematic and realized the pin layout shows the view from the connector side. I was looking at it from the back side. will swap those wires and report back!
 
Back
Top