Why is the sound erratic when using volume control on my receiver?

Hi @bobbo1 ,

I can’t find the service manual or even a schematic for the receiver but it seems as though the volume control and the balance control potentiometers either need to be cleaned with a contact cleaner aerosol spray or possibly need to be replaced.

Most potentiometers have either a carbon track or a wire track where a contact wiper blade runs along and this varies the resistance in the circuit which alters the voltage and current flow through the particular circuit in which it is located.

Over time the wiper blade contact and/or the track gets dirty which creates resistance between the connection of the wiper to the track and therefore the noise etc.

Here’s a link that shows all the various types of potentiometers available.

If you cannot access the ones in your receiver to clean them with the contact cleaner as they are too tightly sealed then you may have to replace them. Their value should be printed on the component itself.