scratchy noise from volume control

[highend64]

Hi I have a Yamaha CX-600U preamp that makes a scratchy noise on one channel only when the volume is adjusted. Does it just need a deoxit on the pot contact? Thanks

 

[Bourbon]

Does it just need a deoxit on the pot contact? Thanks

Probably.

 

[Oerets]

Good place to start.

Barney

 

[savatage1973]

Pop the lid, douse it with DeOxit and work it back and forth. Repeat. Don't forget all the other controls/switches while you are in there.

 

[afewbricks]

Worst case scenario the contacts are getting old and it needs a pot replacement but deoxit usually sets them straight when its just dirty.

 

[highend64]

Ok thanks for all the info.

 

[markn2wae]

Another possible problem.

I don't know the schematic of the set, but if the volume control fails to "clean up" after the De Oxit cleaning (and the control is not worn out) one possibility is that you may have one or more electrically "leaky" capacitor(s) going into and/or leading out of the volume control.

If the capacitor is leaky and is passing DC Voltage to the control, you will have scratching and noises that cleaning will NOT correct, this could only effect one channel (each channel has its own capacitors). :scratch2:

Hope this helps! :yes:

Mark T.

 

[robin fowler]

I am re-opening this thread bc I have a similar problem with my Yamaha RX-500U receiver. When i increase or decrease the volume, I get a loud “screeching” noise from one speaker. I do not get any noise when I adjust “loudness” control. I used CRC contact cleaner on the volume control when I had the case open, but I guess that is not the same as De Oxit? Yes, I am an “infant” when it comes to audio but I am trying to learn!

 

[billyz]

I am re-opening this thread bc I have a similar problem with my Yamaha RX-500U receiver. When i increase or decrease the volume, I get a loud “screeching” noise from one speaker. I do not get any noise when I adjust “loudness” control. I used CRC contact cleaner on the volume control when I had the case open, but I guess that is not the same as De Oxit? Yes, I am an “infant” when it comes to audio but I am trying to learn!

CRC contact cleaner should work if it is a dirty control pot. Spray again and vigorously rotate the control at least 10x . If no better it is likely a different problem . I.E. bad pot, leaky coupling capacitor.

 

[robin fowler]

thank you! that is what i did! i will give it another try.

 

[RTally]

I am re-opening this thread bc I have a similar problem with my Yamaha RX-500U receiver. When i increase or decrease the volume, I get a loud “screeching” noise from one speaker. I do not get any noise when I adjust “loudness” control. I used CRC contact cleaner on the volume control when I had the case open, but I guess that is not the same as De Oxit? Yes, I am an “infant” when it comes to audio but I am trying to learn!

I would not spray contact cleaner into a potentiometer by itself. Contact cleaner will do a good of cleaning inside the pot, but it also does a good job of removing any lubricant, both on the resistive trace and, more importantly, on the shaft bearing.

I would use DeoxIt because it contains a lubricant, along with the cleaning chemicals. The application is the same: spray it inside the housing so that it reaches the wiper and trace. Then rotate the control full ranged many times (more than 10). Depending upon the condition of the pot, it may require several applications of DeoxIt D5. My preference is to use DeoxIT Faderlube, which contains a bit more lubricant and is intended for use on faders (pots).

 

[robin fowler]

ok, i have not done a second cleaning so I will get the one you recommend! thank you!

 

[Bill Ferris]

I would not spray contact cleaner into a potentiometer by itself. Contact cleaner will do a good of cleaning inside the pot, but it also does a good job of removing any lubricant, both on the resistive trace and, more importantly, on the shaft bearing.

I would use DeoxIt because it contains a lubricant, along with the cleaning chemicals. The application is the same: spray it inside the housing so that it reaches the wiper and trace. Then rotate the control full ranged many times (more than 10). Depending upon the condition of the pot, it may require several applications of DeoxIt D5. My preference is to use DeoxIT Faderlube, which contains a bit more lubricant and is intended for use on faders (pots).

,

 

[robin fowler]

ok, that appears to have worked!
thanks everyone!