CTH Volume Pot Replacement

[Jumpwire]

My CTH volume pot has always had issues. It was much worse when I originally purchased it.
Somehow changing my DAC from the D30 made a difference and of course the LPS.
But I can still hear scratches. Could anyone direct me to a replacement ALPS pot?
I would like to solder a new one and fix this issue forever.

Appreciate any help

 

[DKT88]

I've bought audio related parts from parts-express.com. I've also used electronic contact cleaner on pots that are not sealed, avoiding soaking other components. The volume pot in my amp got scratchy recently and not having easy access to contact cleaner in this country I just rotated it stop to stop about 10 times and that has at solved the problem for the last few months. I didn't open up the amp, maybe the pot is sealed anyway.

 

[Jumpwire]

Hmm might look at some contact cleaner, although might be fun trying not to have it leak on anything else.
I tried fiddling with the volume knob with different pressures and rotations. No dice.
Do these pots all come in standadized sizes or did MD use a custom 1 off?

 

[DKT88]

Unless you can find someone who can tell you what the part is, you should open up the case and find out what it is.

 

[Jumpwire]

I might have too, will report my findings when I do.

 

[restorer-john]

Hmm might look at some contact cleaner, although might be fun trying not to have it leak on anything else.

Contact cleaner on conductive plastics pots is not a good idea. You will also lose the silicone shaft/bushing damping as the contact cleaners dissolve that too. Some people like to drill 2x tiny 0.6mm holes into the pot gangs and squirt contact cleaner inside. It may work short term, but will wreck the pot long term- don't do it. Bits of plastic will get inside, the wafers/wipers may be damaged and the conductive path will likely dissolve.

Current production sealed pots are easy enough to source and replace. That is the path I would take.

It appears they used a sh#tbag quality pot in any case. "sanni" brand. Sooner or later (hopefully) people will realise these crappy little pots are a waste of time. Get it out and use a decent quality Alps.

 

[RayDunzl]

It appears they used a sh#tbag quality pot in any case. "sanni" brand. Get it out and use an Alps.

... and match the lead spacing, resistance and taper ("audio", presumedly).

 

[restorer-john]

... and match the lead spacing, resistance and taper ("audio", presumedly).

That goes without saying. Lead spacing will be the same- "Sanni" brand is a clearly a rip-off trying to get Alps business. Shaft length and style also should be noted.

The pot value will be (hopefully) printed on it, otherwise use a DMM for the value and the taper (it will be log).

 

[DKT88]

Contact cleaner on conductive plastics pots is not a good idea. You will also lose the silicone shaft/bushing damping as the contact cleaners dissolve that too. Some people like to drill 2x tiny 0.6mm holes into the pot gangs and squirt contact cleaner inside. It may work short term, but will wreck the pot long term- don't do it. Bits of plastic will get inside, the wafers/wipers may be damaged and the conductive path will likely dissolve.

Current production sealed pots are easy enough to source and replace. That is the path I would take.

It appears they used a sh#tbag quality pot in any case. "sanni" brand. Sooner or later (hopefully) people will realise these crappy little pots are a waste of time. Get it out and use a decent quality Alps.

View attachment 26877

How about the Deoxit contact cleaner for plastic components? Have you used that? I think its "F" type.

 

[restorer-john]

How about the Deoxit contact cleaner for plastic components? Have you used that?

Just replace the pot with an Alps RK097 equivalent. Read what I wrote above, again. Trust me, Deoxit will cost several times the cost of a new, better, genuine Alps pot and you won't be drilling holes and generally asking for trouble.

If you have no rework gear (soldering iron, desoldering station etc) take it to a person who does.

Cheers.

PS. I use Electrolube and CRC products. Deoxit is OK, but grossly overpriced.

 

[Jumpwire]

Awesome, I really appreciate the replies. I will open her up and take a closer look tomorrow.
I have done soldering work before, so this seems like a breeze. Its just finding the right pot.

Wonder if I have to desolder the old pot to get good measurements.

 

[restorer-john]

Wonder if I have to desolder the old pot to get good measurements.

It should be marked on the pot. Usually on the visible sides/back. If you aren't sure, post the numbers/letters here.

 

[Jumpwire]

Will do, thanks again!