Come to think of it, I always have my cell on me and my watch has bluetooth…? in addition to the alarm's cell.
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?
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@wsrrsw typing from Phone is always a challenge, I appreciate your time! I did try a long extension cord to an outlet which is on a different panel (I have 6 panels at home plus the main panel at the interconnection with the utility). Problem was present |
Ok. One more improbable guess. Are the mono blocks near one another or the pre amp? I’m thinking power supply interference. As in the PSU on an Amp or the Pre acting up. The hum problem exists using other circuits so it’s cause is something in your equipment. Got a rubber mallet? Did you try tapping? “Give a small boy a hammer and he will find that everything he encounters needs pounding.” Abraham Kaolan
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I'd love to look at the videos you posted, but I don't have Dropbox, and don't want to sign up for even a trial membership. Can you think of any other way to post them? 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?
...on all tubes at the same time?
I'm not 100% sure, but I don't think that's normal. Of the one stereo tube amp I've had in the past with adjustable bias, I never witnessed anything like that when biasing the tubes. Once the tubes warmed up, the bias values were stable. I've worked on many high power FM transmitters with tubes in the past, and never saw tube bias fluctuate very much there either. Once set, it remained there for a lengthy period of time. I'd like to thank you @ervikingo for staying engaged in the conversation. Many come to this board, throw out a question or problem they're experiencing, and never show any interest, or offer any feedback after that. |
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