I thought of one way in which a tube could cause classic hum as I defined it above: If you have an AC filament supply and especially if you are powering Directly Heated Triodes (DHT), the AC on the filament, which is also the cathode in a DHT, can be amplified and produce audible hum. However, the cure is not to replace the tube but to fiddle with the filament supply or change over to DC filaments.
Tube Question
I have an amp that has Russian Tubes. This amp purchased in the 90's has always had a hum to it which when playing music isn't heard. I'm thinking of buying 1 6SL7 and 1 6550EH tube to swap out and see if I can find if one of the tubes is the problem. The 6SL7 is Sovtek and the 6550EH is electro-harmonix. Should I replace with a similar tube from another company or continue with the same company? Is this approach to finding the problem sensible or a waste of time?
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- 17 posts total
- 17 posts total