PFR: scratchy volume pot

[artm]

I have a slight scratchiness with my PFR's volume pot. Not everywhere, just here and there.

Can I spray some Deoxit in there to help it?

If so, where exactly?

[AnotherJohnson]

De-Oxit is generally a good strategy. I’m not looking at one, but I would suggest you unplug the unit, and give the caps time to discharge. Remove the cover and knob, and do your best to get a squirt into the pot. Twist it a few times back and forth.

Someone else may be able to look at one and make a better suggestion.

[admin]

Agree with above. Often it just needs a good cleaning.

The PFR is a nice unit. I owned owned one for a number of years.

[Big Dog RJ]

Yes, have had the same issue with the PFR's level control very scratchy noise especially when using the remote. Easy fix though, open up the hood and clean out the pots, there are some intricate wires and resistors, just make sure you don't touch those. I think it uses an Alps potentiometer as the main volume control, once this is properly cleaned out, the scratchy will go away.

If it continues or gets worse, which did actually happen with another customer of ours then we changed the entire part, and that was good as new! Not sure if CJ carries stock of PFR parts though... you'd have to inquire.

All the best, RJ

[roberto]

I recommend to you to turn off the unit and moving the knob several times back and forth, the noise will be gone. Using cleaning fluids work fine for some time, and the replacement for the control is a must.

Happy listening!

[artm]

The noise is only apparent with no music playing. I can certainly live with that as is. Turning it back and forth does help a lot but I thought Deoxit would provide a more long term solution.

I'll take the cover off and see how it goes soon.

[roberto]

That is another kind of noise. If the noise is constant maybe is a tube, if the noise a kind of rattle, then it could be a noisy resistor or a crystallised solder joint. Moving the knob without any music, the noise is about the same level or it increases? There are parts where the noise is louder and worse. There is where you should move the control knob to clean the debris or rust that are doing that noise.
If you use a cleaning fluid, it could erase the carbon layer deposited of the variable resistor. It is better to clean it with the knob. Also the noise tells that the unit is not in a continuous use. Using it will make the volume knob noise to go away.

This is my 2 cents. It is your unit. The variable resistors are not too expensive, A brand new volume control will work soft to the touch and no noise at all.

Happy listening!

[artm]

I've included some pics of the pot. Can anyone advise exactly where I should squirt in some Deoxit?

If it means I need to take it out, I probably will leave it alone, as the noise is only heard with no music - and not much at that.

[AnotherJohnson]

Pick a hole … any or all. It’s harmless.

A good squirt adjacent to the shaft is never a bad idea. Like penetrating oil, it will find its way into the mechanism.

You’re not going to take it apart not soak. The carrier will evaporate. The abrasion of the knob turning should reduce contact resistance and help with the noise. If it doesn’t, you’ll have to think about replacement.

FWIW, on my Rivera guitar amps, I pull the knob and find a flat on the shaft for he set screw. The flat provides a passage way into the pot. A squirt and a twist is usually enough.

You’re basically hoping to put deoxit into a place where it can wick into the interface.

Nothing ventured, nothing gained.

[artm]

Got it...I just tried this on an old receiver, just letting it drip down the shaft, and it instantly worked. Will try it on the PFR soon.

[admin]

If you are worried about it dripping too much you can put a lint free cloth around the pot. It will prevent splashing or excess drip on other components. But as AJ mentioned, it's not going to damage other electrical components so it's safe to "make a mess".

[roberto]

The back part is a motor for the knob. The purple and green cables are for the motor's working voltages. So, if you want to try, just where the motor ends, the control has an opening on both top sides. Where says 5041 100KAX2 on both sides apply just a little bit and you are done.

[artm]

Success. Took off knob (very small allen key), propped the unit face on lap, squirted Deoxit at the base of the shaft. Turned shaft several times.

The key is to wait long enough for the fluid to get down far enough. First time I did it there was a small scratch effect after it was reconnected. I didn't squirt it again but just turned the knob several more times. All the scratchiness is now gone.

[AnotherJohnson]

Congratulations!

[admin]

Very nice! Enjoy the tunes!

[roberto]

Good job!

Great to know that the pre is back to offer CJ quality sound!

Happy listening!