Pendulum: no sound

[yangushii]

Hello everyone,
I have just completed the Pendulum Harmonic Tremolo. But I am getting no sound when the effect is on. (Sound goes through when bypassed)

The on Led is lighting up and the LFO led is blinking and the speed pot is changing its speed.
I can also hear a feint ticking of the tremolo which changes as well when turning the speed knob.
But absolutely no sound is output even at maximum volume volume pot.
I did not use a dust cover on the volume pot but isolated it with red tape.(same as the one i used on the led/sensors from the picture)

Having no schematic and little experience, I am not sure how to troubleshoot this.

Any help is welcome

 

[carlinb17]

It looks like your bottom ic is upside down, additionally your foot switch breakout board is upside down. You should also connect the grounds from the board to your jacks.

Build doc.

https://docs.pedalpcb.com/project/PedalPCB-Pendulum.pdf

 

[yangushii]

It looks like your bottom ic is upside down, additionally your foot switch breakout board is upside down. You should also connect the grounds from the board to your jacks.

Build doc.

https://docs.pedalpcb.com/project/PedalPCB-Pendulum.pdf

You are correct indeed. That's quite a shameful mistake. Thanks for pointing this out. I've corrected both but still no sound. I will look at voltage around that IC pins when I have a bit of time and report back here.

Y.

 

[carlinb17]

Did you fix the breakout board? There are traces in the board that if reversed will be problematic

 

[chongmagic]

Yep IC is upside down and the breakout board has the 3pdt switch soldered on the wrong side. All the wiring there will be incorrect due to this.

 

[yangushii]

Yes, I turned the second IC around and re-soldered the 3PDT board correctly.
I'm still having the same issue.

 

[carlinb17]

can you post images of the changes and the back side of the board, you may have also damaged the IC when it was flipped around.

 

[yangushii]

can you post images of the changes and the back side of the board, you may have also damaged the IC when it was flipped around.

I thought the same and I used a spare TL074 I had, just to be sure.

Here's a new picture.

 

[carlinb17]

A picture of the under side could be helpful, I would also suggest grounding your jacks per the wiring diagram. I would reflow, and if you have an audio probe start tracing, if not make one and start tracing. I still suspect your foot switch is the problem or at least part of it.

 

[yangushii]

Thanks Carlinb17!
I followed your advice and re-wired the switch completely: It now works like a charm!
It does sound brighter than the dry signal but I guess that's part of the circuit (i see some post regarding that in the forum)

Thanks again for the help.

Y.

 

[carlinb17]

Thanks Carlinb17!
I followed your advice and re-wired the switch completely: It now works like a charm!
It does sound brighter than the dry signal but I guess that's part of the circuit (i see some post regarding that in the forum)

Thanks again for the help.

Y.

Enjoy!