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axiomofchoice
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Sounds much more like this: https://blogs.qsc.com/app/uploads/sites/3/2022/11/60-cycle-hum-27405.mp3
... recently noticed a faint hum or buzz coming through the speakers. One speaker hums a little louder than the other -- I can just hear the louder one from like 2 feet away, while the other I can only hear with my ears right on the speaker. It seems to be the amp itself, as I unplugged everything connected to the amp (besides speakers and power) and it still hums (that rules out ground loops), and if I swap the speaker cables on the back of the amp, the humming swaps speakers (that rules out speaker cables and speakers).
Does not sound like 60Hz hum. And if it is only in one channel, it is not normal.Sounds much more like this: https://blogs.qsc.com/app/uploads/sites/3/2022/11/60-cycle-hum-27405.mp3
Well, it depends on how the mute function is implemented in the amp. It can be at the input, it can be at the output or it can almost anywhere in the signal path. Wherever it is (and you can probably find it in the schematic), the hum/noise culprit is probably after it so that it is unaffected by the muting.@Kal Rubinson just want to add one more piece to this puzzle. The Michi x3 has an “auto mute” feature which apparently opens a relay when no signal is detected for a little while. Thid is a relay because one can hear a little click when it opens. One can disable this feature but it’s enabled by default.
So I’ve tried it both ways and the hum is constant no matter what. So how can there even be a hum through the speakers if this mute function is doing what it supposedly does?? Seems odd to me.
I could send it back for them to look at it ... Shipping cost is minimal.
For completeness, here is a recording of the speaker hum: https://www.dropbox.com/scl/fi/p064...ey=y7t6k75oithowt9ryf3jxroz9&st=yx6zv2t7&dl=0
I measure it at 35db using NIOSH SLM app on my iPhone with the microphone within 1 inch from the tweeter/midrange.
Tmraudio said that since it’s within the 90 day window for dealing with defective equipment, I could send it back for them to look at it, but it’s not clear what the outcome would be Maybe they would find that it is operating within spec? Maybe they could fix it? Not clear. Shipping cost is minimal.