Duo-Phase Ticking when left side switch engaged

[Pete's Pedals]

Makes the dreaded ticking noise, but only if the left side (the green knobs) is turned on. If the red side is on it sounds wonderful, and I can switch between which LFO is controlling the speed and depth. When running the in and out just through the left (green) side the effect is not as pronounced as when I run it just through the right (red) side. The red side also seems more sensitive to changing settings on the trimpots while the green side trimmers, though changing what happens with the LED, doesn't seem to change much with the actual sound of the effect. I tried moving the input wire farther away from the LED on the green side, but it made no difference. Any suggestions ?

 

[benny_profane]

Let's see the guts. It may be as simple as avoiding the LFO block, but pictures will help.

 

[Robert]

Yep, this is usually caused by the wire coming from the input jack being too close to the LFO section of the PCB.

 

[Pete's Pedals]

Yep, this is usually caused by the wire coming from the input jack being too close to the LFO section of the PCB.

So, after this pic (I had read this somehwere else here) I disconnected that green wire, pulled it out from under and attached above and got it out of the way. No change at all. And the green wire on the red side runs right under the LED with no sound.

 

[benny_profane]

Try routing it so that it hugs the right side of the enclosure. The LFO block is more than just the LED.

 

[Pete's Pedals]

Thanks - I will try that. Maybe proximity to the enclosure helps with the shielding.

 

[andare]

Maybe use shielded wire for input and output, grounding one end on the jack sleeve?

 

[Pete's Pedals]

Nothing is helping so far. Still clicking on the green side. Dead quiet on the red side. What else can cause this?

 

[andare]

If the effect is less intense on the green side maybe there's another issue. Did you test the circuit before boxing it up and, if so, did it work properly then?
Maybe some of the signal is draining to ground somewhere?

 

[benny_profane]

Is the ticking present if you run them in series? You can zero in on where the ticking is happening by checking the different input/output combos.

If it’s not interference, you could increase the power filtering (i.e., series resistor and cap to ground) or use a lower current draw IC (e.g., TL062 or TL022) for the LFO. Since these are mirrored blocks, my suspicion is still interference. So, making wiring as tidy as possible and completely avoiding anything with the LFO. Additionally, you could give shielded wire a shot.