Dual cv40 amp - issues with volume pot/ control

[Bunya]

Team I have a dual stereo, which includes matched reel to reel, tuner, speakers, cv40 amp and 1219 turntable.
 

 
Recently my amp started to get a crackle in the volume control and the left channel would drop out at low volume.
 
In an attempt to remedy this I blew the dust out and applied some electrical contact cleaner and lube.
 
This did nothing for the volume control. While the amp was off I tried turn the volume up and down multiple times to see if I could free and dust or corrosion. After this process the left channel was cutting out over a greater range, from low to 3/4 of full volume.
 
One way to get the sound out of the left channel was to slightly put a skewed pressure on the knob like you are pushing it laterally.... the second the pressure was eased of the channel would cut out.
 
Does this sound like a broken volume pot? Are they easy to replace?
 
On the dual cv 40 volume control it has a contour and linear feature where you can push or pull the knob to select either option before selecting the desired volume. Are replacement pots still available with the above mentioned functionality?
 
 
I’m keen to hear your thoughts.
 
Cheers
Bunya

[Addicted to music]

 

 

The carbon wafer is possible worn out, the ,leaf spring tension on the contact has either lost its pressure or you have DC applied.

 

Cleaning may have an effect but usually does more harm than good as some pots have conductive grease applied.

 

See if you can find a replacement for it, and once replace don’t look back.   

[Zaphod Beeblebrox]

There are usually two reasons for a noisy pot.

 

* Dirt, dust and/or worn carbon tracks. 

* A small amount of DC on the pot.

 

With the first, you have two choices: Clean or replace. 
With the second, you need to measure the DC Voltages on the pot. If there is some DC (usually >0.05 Volts), then you need to locate what is causing the DC on the pot. Frequently, in old amps, this would be a leaky coupling capacitor. 

 

The chances of obtaining a replacement pot are two: None and Buckley's. You will probably need to accept the loss of the push-pull function. 

[Bunya]

Team the planets have aligned! I have managed to track down and order an original spare part! Thanks for the tips!

[Zaphod Beeblebrox]

1 minute ago, Bunya said:

Team the planets have aligned! I have managed to track down and order an original spare part! Thanks for the tips!

WOW! Where from?

 

Don't forget to check for the presence of DC on the pot, as this may be a major cause.

 

[Sam Z]

Cool system.

 

As above, check for DC at the pot...