Attenuator Help - I have Static!

[casanis]

Hi All,

I purchased a built Foreplay III from a fellow bottlehead enthusiast a few months back. Everything was going fine until I noticed static coming from the right channel this morning. I have narrowed it down to the attenuator for the right channel. It sounds like a dirty potentiometer would sound - i.e. wiggling it ever so slightly will re-establish connection (or changing from one step setting to another and back again). Anyway, I was wondering if there's anyway to clean the contacts within the attenuator itself? I have ruled out any of the solder connections or damage to the resistor grid on the back.

The static is not localized to one specific "step" or "setting" - it can happen on any of the 10 steps.  

If cleaning is not an option, would it be possible to order a replacement attenuator (as well as associated resistors required between steps). I know the Foreplay III has been retired    If there's anyone out there who might be able to help, it would be most appreciated.

Many Thanks,
Adam.

 

[randy@matrixq.com]

Some Deoxit will help a lot.  Look online or at Radio Shack.

The FP3 should have stepped attenuators as stock, though your issue sounds like carbon pots.  There are plenty suggestions for replacements on the forum.

Can you post a close up of the underside?

 

[casanis]

I'm sure I have the stepped attenuators - it is a stock kit build. I will try the deoxit ASAP.

I will post up some pics once I arrive home from work tonight.

Cheers,
Adam.

 

[Doc B]

There are a couple of things to try - a spritz of contact cleaner as has been properly suggested as a first step. And if that doesn't fix it, the next step would be opening up the switch and bending the wiper contact to make a better connection. That is a bit tricky, but it can be done. The main issue is that there are parts that can fly out when you open up the switch. If you decide to open it by prying open the little latches around the perimeter of the switch, understand that there are little springs and balls that maintain the contact pressure, and they might go flying if you aren't prepared for them.

 

[casanis]

Thanks Doc. Will try the contact cleaner first...

 

[Frank Breech]

Casanis,
Did the contact cleaner end up working for you?  I'm having the same problem

MIke

 

[earwaxxer]

My two cents on attenuators - There are many good ones to choose from today, for not much bucks. I personally like the plastic log pots. I think the carbon pots can crackle like that. For less than $25 each you can play with pots. Kind of fun. Everyone and their brother seem to like the Alps Blue Velvet. I have several of them. I like them. I also like TKD. Stepped resistor attenuators are the 'best', but may not server your needs (ie. being stepped).