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?
Hi ervikingo: Are you using a dedicated line? Try to twist to single wires between them and connect from main breaker to your amps. This is one way to avoid some frequencies to interfer. You can also remove ground fir a while from your socket. Ask for the guy if you are not familiar dealing with electricity. Good luck! |
@dpop thanks to you and all others staying engaged with my dilema. I’ve been at this for weeks. "After powering up the amps, how long before the hum appears? Does the hum then remain constant for the rest of the time after it first surfaces, or does it come and go?" It takes 1 to 2 minutes to manifest. Once it starts, it doesn’t go away "...on all tubes at the same time?" That I can see on all EL34/KT77 I’m going to upload to youtube and post a link
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@wsrrsw It ain't Hammer Time buddy! Noise is present even without interconnects |
@atmasphere Thanks for sharing your knowledge! I'll read more about it. I have asked the power company to come test their system. I hope they stick a tester to their lines before coming to see inside. I'm afraid they might take the easy way out and blame the amps |
@pinotnoir it is a dedicated line/breaker to the music room outlets. These feed the head units,4 monoblocks and a projector. Keep in mind, Everything but one tube amp is connected at a time as I try to find the problem. I originally had dimmers (fancy wifi ones) which I took out and replaced with standard non dimmable switches (no dimmers in the whole house now). As I remove more things from the chain, my mind circles back to what I can't remove: whole house surge suppressor (https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.grainger.com%2Fproduct%2FSIEMENS-Surge-Protection-Device-Three-19T314&psig=AOvVaw2Rhsn6b5q61wEg7Jj_-WGO&ust=1670625130078000&source=images&cd=vfe&ved=0CA8QjhxqFwoTCPC7jNuJ6_sCFQAAAAAdAAAAABAE); Generac ATS and alarm cell. |
