Lovepedal Champ - Loud hum

francisbeaulieu · Post by **francisbeaulieu** » 04 Mar 2023, 17:13

Hello,
This is my first pedal project, so please forgive me if it looks like crap.

I though I'd start with something easy, the Lovepedal Champ, using this layout: https://tagboardeffects.blogspot.com/20 ... champ.html
which is based on this thread: viewtopic.php?f=7&t=28220

The effect works as it should (I think), but I also get a loud hum whenever the effect is switched on. Could it be a grounding/shielding issue?
I have built an audio probe to test it, but I'm not exactly sure where to test, and what I should be looking for.

Here's a picture of what it currently looks like (I'll make it neater once it works and the enclosure is painted)
Green wire at top is ground, blue wire is +9V, green wire at bottom left is LED.

Thanks!

Manfred · Post by **Manfred** » 04 Mar 2023, 17:35

Did you follow this wiring:
https://tagboardeffects.blogspot.com/20 ... iring.html
Check the wiring according to the pattern.
If this is in order give us a shot of the solder side of your board.

francisbeaulieu · Post by **francisbeaulieu** » 04 Mar 2023, 18:50

Thanks for the quick reply. I've used a different wiring guide, but the result is pretty much the same, except there is no jumper between lugs 4 and 7 of the switch (but adding one didn't make any difference)

Here is the back of the board. It doesn't look as nice as I hoped, but I was also afraid of overheating my components.

I'm about to unsolder some wires and bypass the switch to make sure the problem comes from the board.

Thanks again!

mauman · Post by **mauman** » 04 Mar 2023, 19:36

I can't quite follow your ground wiring scheme - are all the grounds connected in some way? Looks like you are using the enclosure to ground the in/out jack shields, sometimes that works and sometimes it doesn't. A hum with the pedal engaged could be a missing/disconnected ground.

francisbeaulieu · Post by **francisbeaulieu** » 04 Mar 2023, 19:56

Sorry if that's unclear.
Ground wires are green.
Ground from LED goes to switch, switch goes to jacks, jacks go to negative lug (center) of the power supply. Lug 1 of the pot goes ground strip on the board, board ground goes to jacks.

Besides the short length of wire between sleeves of in/out jacks, there is also continuity through the enclosure (I checked).

F.

francisbeaulieu · Post by **francisbeaulieu** » 05 Mar 2023, 04:03

Update:
While I was trying to troubleshoot it tonight, I accidentally disconnected the ground from the board to the jack. The pedal worked, and the hum was pretty much gone.
What does this tell us?

F.