Help with MXR DYNACOMP compressor MICROPHONIC

[Atodovax]

Hello everyone. Im experiencing something really strange. I built the effectslayout Mxr Dynacomp and the effects works great but the pcb is super microphonic. At first i though the 3pdt POP i was hearing was something realated to pulldown resistors but i´ve tried everything i know (adding capacitors, pulldown resistors, removing LED, AMZ LED poping solution, changing 3 different 3pdts (from different brands) changing all electrolytic capacitor and nothing got rid of the strong "TIC" that i hear when i press the switch. I know assume its the circuit picking the mechanical noise. The input wire is super microphonic as so the input capacitor which i changed. In fact all the circuit is making noise if i hit something close enough.. Any ideas? Im suspecting the 3080ce chip might be causing the problem? The pedal compresses perfect so i dont know what to do. Also changed the 6 transistors with no luck.. Theres definetely a point thats gone microphonic or is generatting an awfull amount of gain

[patrick398]

I think ceramic caps are the usual suspects for going microphonic. Don't think I've ever experienced that issue myself. Are there a lot of ceramic caps in the circuit? You could go through one by one tapping them with a small screwdriver to see if one is giving you noticeable problems. You said that the whole circuit seems to be microphonic though so may not help. Are you're input or output caps electros? Are they the correct way round? Are you getting any voltage on the input or output?

[idy]

The test to narrow down microphonics is to gently tap with a pencil or something individual components. Ceramc caps are famous for this.
Cold solder joints may appear perfect even "under the microscope" but the component lead moves just a tiny bit.
Sometimes I have had foot switches that pick up taps...
It is interesting how we can be quite convinced that the problem is one thing, and then discover it is something else.

[Atodovax]

Thank you very much for the replies. So the "noisiest" point on the pcb was the 2k trimmer (hitting everything with a pencil. There are no ceramic caps. Inpu cap is Wima MKT red box as most of the other caps exect for the 1uf tantalums and 47uf and 10uf electro which are both good. Im soldering everything again right now and post back the results. I´ve never experienced something as microphonic as this. I could literally hear "tiiiiiiing" when i hit the enclosure with a petal screwdriver or hear the 3pdt "bounce"