Noisy pots when I turn them fast

[Tdale]

I'm rewireing my DC30, to get rid of the rats nest of wires.

There is some hum, but I hope I'll get rid of that.

The pots are quiet, but when I turn them really fast, there is a scratchy sound... Is that natural?

But is generally scratcy pots caused by DC-leackage? or dust/worn out pots?


Tommy

[Bob-I]

Is that natural?

But is generally scratcy pots caused by DC-leackage? or dust/worn out pots?


Tommy

That pretty much sums it up. Turning fast can scratch, DC leakage and dust too.

[dehughes]

What is an "acceptable" amount of DC to find on a coupling cap/tone pot? I'm measuring about one millivolt or less on mine...

[Bob-I]

What is an "acceptable" amount of DC to find on a coupling cap/tone pot? I'm measuring about one millivolt or less on mine...

a few mv is fine. If I see a volt or more I look for a leaky cap. The exception is the presence pot where there's the expectation of scratchyness.

[dehughes]

What is an "acceptable" amount of DC to find on a coupling cap/tone pot? I'm measuring about one millivolt or less on mine...

a few mv is fine. If I see a volt or more I look for a leaky cap. The exception is the presence pot where there's the expectation of scratchyness.

AH, thanks, that leads to my next question: I found about 43mv on one lug of my "cut" pot and about 13mv on the other (think Vox AC30, Matchless DC30, etc...one lug going to one plate of the PI, the other going to a .0047 cap and the other plate of the PI....).

Does that seem normal? I mean, you have about 230v on the plates of the PI, but then shouldn't you not see any voltage on the other side of the PI coupling caps?