Noisy volume pot

[bulgin]

Hi guys

There's a problem with a noisy volume pot on my Arcam integrated, probably made worse by the cold, damp weather and lack of use in recent months. I have 'exercised' the pot by moving it forwards and backwards many times. This works for one session of listening but then the crackling returns.

Is there anything one can do to fix this kind of thing? I have Kontakt contact cleaner but I don't think this will the right kind of cure.

What about an application of compressed air?

bulgin

[stoolpigeon]

Try a tiny bit of what everyone uses and what everyone else says not to use - WD40.

[OzMikeH]

you can buy contact cleaner and also contact cleaner/lube. the later one is best of course.

Otherwise use contact cleaner, give it a good wash. then a tiny dab of a fine oil. Not sure why WD40 is bad, it's just diesel. Perhaps it's not expensive enough for audiophiles.

[bulgin]

Hi stoolpigeon

Thanks. I have WD40 and was thinking about a wee drap of that...

I think I'll try a bit of compressed air or a vacuuming first and then the magic stuff in a can. It's a motorised pot. Probably Alps.

Regards

bulgin

[Nordic]

With your skills and machines, you can make a new one uncle B.

[bulgin]

Thanks to you too, OzMike

I've got both of the recommended 'cures in a can' in my workshop.

I don't really like that Kontakt stuff as it makes a runny, blue mess. I'll work on it later today and report back.

Cheers

bulgin

[stoolpigeon]

bulgin, how about some more photos of your cartridge?

I would love to see some pics of the parts and how you make them, without giving away any secrets of course.

Can you advise on soldering the fine coil wire? I have made a planar tweeter using the wire from a cheap mm cartridge and I find that removing the varnish with a knife or file breaks the wire but if I just use my iron with a flux then the wire seems to burn away or becomes very weak and breaks easily.

[Elvee]

Originally posted by bulgin
Hi guys

There's a problem with a noisy volume pot on my Arcam integrated, probably made worse by the cold, damp weather and lack of use in recent months. I have 'exercised' the pot by moving it forwards and backwards many times. This works for one session of listening but then the crackling returns.

Is there anything one can do to fix this kind of thing? I have Kontakt contact cleaner but I don't think this will the right kind of cure.

What about an application of compressed air?

bulgin

If your problem is caused by damp conditions rather than wear and tear, here is a remedy:
Open the rear cover, connect a flying wire to the mobile part of the wiper and connect a lab PSU set at 2V 3A between this wire and the outside wiper terminal; make a dozen back and forth revolutions and then spray vaseline (Kontakt 701) on the whole.
This routine burns the oxide layers that form on various metallic parts; the wiper in contact with the track does normally not require cleaning because the track is mildly abrasive.
Cheers
LV

[AndrewT]

Hi Elvee,
this procedure is going to send 3A through the end of the track and the connections/wiper at the low resistance end.

Are you seriously recommending this?

[Elvee]

Originally posted by AndrewT
Hi Elvee,
this procedure is going to send 3A through the end of the track and the connections/wiper at the low resistance end.

Are you seriously recommending this?

Note that the track is completely out of the circuit (which is why you need to remove the cover).
But yes, it works for many types of rotating or sliding contacts; it also works for variable capacitors f.e.
Of course, you have to exercise your common sense: it would be unwise to send 3A into a micro-miniature device, but a standard size pot can easily take 3A in its wiper (not through the track, obviously) for one or two dozen of seconds.
LV