Tube amp buzz (amp, not speakers)


Hello - 

Almarro a318b makes buzzing sound at random: sometimes it does, sometimes it doesn't, completely unpredictable. The buzz comes out of the amp itself, like a transformer buzz; the sound out of speakers is completely clean. 

I'll appreciate any ideas - what causes it, what to do?
boriso

Showing 2 responses by noromance

Have you checked to see if there are sources of noise like a worn refrigerator compressor motor or dimmers coincident with the buzzing? What about trying a direct run to the house breaker panel?
Run with the cover off and when buzz starts, touch various parts of the transformer and chassis and see if you can identify what is vibrating. Once you locate that, you can address it.