Microphonic Tubes

A _microphonic tube_ is one whose electrical characteristics are affected by mechanical vibrations. (This is a flaw.)

If you lightly tap on a microphonic, while your organ and/or amp is on, you'll probably be able to hear noises coming from your speaker.

Microphonic tubes can often be a cause of feedback, buzzing noise, distortion or other bad sounds. If you find one, you should replace it. If you can tap time on your organ case and hear the taps in the speaker, you need to start hunting the mic.

Hammonds can become microphonic in other ways too.. the expression pedal works a capacitor which can become a capacitive microphone if the blocking cap leaks tube plate voltage onto it. If the microphone seems to be inside the transformer can beside the preset bars, the transformer core can take a permanent magnetism and become a dynamic mic.. degauss the transformer. Can2Can

TopicTroubleshooting