Buzzing sound while turning volume switch.


I have a BC21 and recently when I turn the volume switch, what could be the possible caused and is there anything I can do?
vintage
either the amp too old or your place too humid (like seashore or near hill)

need to get tech man to clean the blemishes (if any)
Or there's a loose connection. The BC21 is wired point-to-point and some of the components are supported by the wiring. I had a similar problem with a BC 21 which deteriorated into more noise. Cured with one dab of soldering iron. Open it up and look for something loose, probably connected to volume control.
You should contact Angela at BCircle@BlueCircle.com
Tell her I send you if you want.
have a knowledgable tech spray the volume pot for you with an oil-free cleaning solvent (& then work the control end-to-end several times before the spray dries - tech should know to do this). If the symptoms continue then move on.