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?
@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. |
Cool! Thanks!
They’ll possibly pull the meter (if they do it quick enough, your generator won’t kick on), check some connections, and they *might* put a logging device on your feed (to monitor your power for a period of time). If you’re around when they get there, they may ask you some questions as to the problem(s) you’re experiencing. Some power companies are also more concerned for their customers needs than others (so be aware). If I remember correctly, most electric companies shoot for 120/240 volts +/- 5 volts. If your voltage fluctuations are within that tolerance, they might ask you then to call an electrician, and have your internal wiring checked out. Technically your local power company is typically not responsible for anything past the meter, so most times they won’t want to enter the property if they don’t have to. Unfortunately, the link you provided above does not work. I’m guessing it’s for a surge protector you’re using. I notice that you have an ATS, but yet the SS amps are quiet with it. Would I be correct in stating that the hum is in sync with when the amp puts through audio (ie, the hum starts at the exact time the amp has warmed up, and is now passing audio)? I have to ask this question. To hear this hum, are you putting your ear against your speaker, or can you hear it from 3’ away?
Hum drives many audiophiles a little crazy, because many of us spend thousands of dollars on equipment, expecting after hooking it all up, to have dead quiet backgrounds. As frustrating as it can be, that unfortunately is not always the case.
Does unplugging the projector have any effect?
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