Boss sd-1 noise/microphonic

[Tpruitt]

so I picked up a silver label sd-1 to compare to my black label. (Silver is on the right in pic).
Volume at 9 o’clock and gain at 8 o’clock (almost off) the silver label has this hum and it gets super loud the more you turn up gain and/or volume.
I tried it with a battery and no change.
I then took a look inside and it look unmodded. I then started moving around a few wires and the battery cable it super microphonic when tapped on.
The other wires for power are slightly phonic but nowhere near as bad the the battery cable.
I checked pins 6/7 of the 4558 chip is right around 32k with gain off and 989k all the way up so the gain pot looks good.

Any one come across this before.
Any suggestions?

Thanks

 

[Tpruitt]

So I went through it again.
The input wire is definitely the the loudest wire when tapping on them. Second would be the hot (power) wire. The power wires aren’t really much worse than the older pedal though. But the input wire from the input jack is.

So, what do you guys think if I used a shielded cable here?

 

[Nostradoomus]

Tap on the capacitors with a wooden chopstick or something small and non conductive. If one of them makes a good thud, replace it.

 

[Tpruitt]

C1,c2,c3 do thud.not as loud as the input wire though. But they do in the older one too that doesn’t have a noise issue.

 

[jwin615]

C1,c2,c3 do thud.not as loud as the input wire though. But they do in the older one too that doesn’t have a noise issue.

I'd swap those and go from there. May be leaking DC and causing the input to thud. Can also try to measure DC on the jack for S&Gs

 

[Tpruitt]

I'd swap those and go from there. May be leaking DC and causing the input to thud. Can also try to measure DC on the jack for S&Gs

Swapped capacitors and no better.