Power Amp transformer hum - intermittent and increases and decreases in a few seconds


Checking to see if anyone can tell me if blue circle power pillow or emotive cmx-2 can solve my hum issue. Or is there something else I should be liking at?
john_simp
don_c55826 posts

03-11-2019 4:16pm

My Pass Labs XA60.5 never buzzes and it has Toroids.

Just a guess because Pass Labs incorporates a DC blocker in their power amps.



Bryston does......
https://www.diyaudio.com/forums/power-supplies/161428-variations-dc-main-filter-buzzing-toroid-trans...




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Mechanical hum is not always the result of DC offset. I have some DC offset on my mains and even two DC blockers in series couldn’t eliminate an obnoxious hum in one of my amps.

Anyhow, I own the CMX-2 but found the Audio By Van Alstine Humdinger works far better. I had a bucking transformer that still hummed loud when plugged into the CMX, but it ceased completely with the Humdinger.
Try a cheater plug.

A cheater plug should only be used to help diagnosis if you have a ground loop problem.  It is not a solution as it poses a safety risk.

Agree.  I did try a cheater plug to no avail.  Thx to all for their input. It is much appreciated.