Scratchy volume pot

4

I have an old Crown D-75 amplifier that I acquired a while back and it works like a beaut except one issue.

When I turn the pots on the volume control it creates a scratchy sound. Is this something that can be easily cleaned?

Edit: It looks as though one of the pots is toast and needs to be completely replaced so I moved the 'how to replace a pot' to its own question. I also removed the 'replacement-parts', since this question is more of a 'fix' than a full-out 'repair'.

Evan Plaice

Posted 2011-02-10T23:35:11.427

Reputation:

Answers

7

I would try cleaning it first with a non-residue, non-conductive contact cleaner. DeOxIt is the most widely recommended spray.

Here's a good read (with pics!) by someone with a similar problem.

BenV

Posted 2011-02-10T23:35:11.427

Reputation: 3 595

Ordered myself a can of DeOxit spray (i have the 100% solution with applier)! have a G series channel strip in my bench being cleaned and will give it a go. Only not to sure about the fact that it doesn't have any lube factor. – None – 2011-02-11T19:27:27.033

+1 for DeOxit. Great for cleaning guitar/amp/vintage pedal pots too. – None – 2011-03-14T12:34:47.257

2

We use EML on our SSL parts. In addition to cleaning contacts, it also lubes the whole mechanism. I use DeOxit mainly to clean faders and then apply the deoxit lube on the fader rail (for instance, your D-Command Penny-Gilles).

Never tried DeOxit on knobs before maybe because of the lack of self built lube, and the fact that the spray actually helps the solution to get inside the pot. Specially for enclosed pots.

I would first apply some compressed air though. Remember to keep the can right up, and exercise the pot after applying.

Remember - Gravity is your friend. So if you can even have the knob in a way that allows you to squirt the DeOxit or EML or IPA from the top, the better!

If the thing doesn't really do the trick (still has some residue on it) go for something a bit more abrasive like IPA (isopropanyl) but then re-apply EML for the lube factor.

EDIT: decided to make an edit here after reading @BenV link - Do not use anything like WD-40. When I mean lube, it's a very thin layer that it's left there, non abrasive and non-sticky, nothing like WD40! Just making something clear before it becomes source of confusion!

jlebre

Posted 2011-02-10T23:35:11.427

Reputation:

0

As BenV said, clean it. Also, using it often helps. I got an old Harman Kardon many years ago with this issue. It has since gone away, most likely it was dirt/oxidation from non-use. It also had several switches that sometimes worked, sometimes not, and they also got much better with use.

Lennart Regebro

Posted 2011-02-10T23:35:11.427

Reputation: 1 430

I hate to nitpick but isn't this more of a comment on BenV's answer than an answer of its own? – None – 2011-02-12T00:25:56.587

Maybe. Maybe not. Using it does help, but it's not a quick fix. – Lennart Regebro – 2011-02-12T09:35:14.050