SOLVED Kliche Mini: Weird high pitched noise

[jeffwhitfield]

Ok, so I'm finishing off a batch of Kliche Mini's and have a few that need debugging. A couple of a weird tone issue but I'll loop back to those later if I can't find the issue. In the meantime...

I've got one that has a rather odd high pitched noise around 3.55k. I matched it with a tone generator. This occurs regardless of whether the pedal is engaged or not so it definitely is happening in the buffer. The noise gets louder when the pedal is engaged.

I've switched out both op-amps and the charge pump to no effect. Noise goes away when I jumper pins 1 and 8 on the charge pump. So, I'm thinking it's a pesky component somewhere in the buffer. Leaky capacitor perhaps? Maybe one of the 1uF caps?

I'll post pics later if needed.

 

[manfesto]

Noise goes away when I jumper pins 1 and 8 on the charge pump.

That’s your problem and your fix; pins 1 and 8 need to be connected for the charge pump to boost its operating frequency outside the range of human hearing, for whatever reason they’re not (burnt/lifted pad, cold joint, damaged trace, etc) and that’s what you’re hearing.

 

[music6000]

I've got one that has a rather odd high pitched noise around 3.55k. I matched it with a tone generator. This occurs regardless of whether the pedal is engaged or not so it definitely is happening in the buffer. The noise gets louder when the pedal is engaged.

Do a Continuity check on Pins 1 & 8 with the Charge pump removed.
If no Continuity, the Trace is missing or Damaged as manfesto stated!
Jumper if Faulty!

 

[jeffwhitfield]

That’s your problem and your fix; pins 1 and 8 need to be connected for the charge pump to boost its operating frequency outside the range of human hearing, for whatever reason they’re not (burnt/lifted pad, cold joint, damaged trace, etc) and that’s what you’re hearing.

Yup, that’s exactly it! Tested the continuity, jumpered the pins on the back, and all tests fine Thanks for the tip! Problem solved!