Hum on Tube Amp - Can't find source
I have a hum (60hz) I can hear on my speakers and it happens with my tube monoblocks (either of them). With or without interconnects, it even happens on either amp (have tried one at a time) with every circuit on the house tripped/disconnected, every other component disconnected from the wall (including the Internet/CaTV line) and no interconnects.
One amp has it as soon as it warms up whereas the other one is intermittent.
Hum X doesn't solve it, iFi Ground defender either, AVA HumDinger on powerline doesn't solve it either.
I have replaced the tubes and both amps were just tested at the factory. Replaced the circuit breaker, tightened every wire on the breaker box, checked and cleaned all connections to ground rod. Added a hum eliminator to the internet line.
Hum cycles a bit with the tube glow matching the cycles.
I'm waiting on the power company to come check the power coming to the house.
Thoughts?
Had this problem with a Primaluna Prologue Premium and Klipsch LaScallas. Sent amp to Upscale Audio (Indianapolis to L.A.) who checked out the amp and said it was working normally. Never fixed the problem so I sold the amp. I believe the problem is/was in my main panel but didn't want to hire an electrician. Doesn't affect my current equipment. Good luck. |
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Get yourself something called a Digital Voltmeter. Set it to the AC scale and plug the probes into your AC power. Keep an eye on the voltage; when the hum shows up look at the voltage and see if its changed. Or you could also use one of these: The nice thing about this item is it can also measure the current drawn by an amplifier. It would be interesting to see what the current and AC voltage are doing when the amp hums. |
Thanks to all of you! @jea48 none matches. Going to try to link a sound file and video. @atmasphere I ordered that meter you linked. I will try and report back. I assume put it around the power cord to the amp? |
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