The transformer on my old ATM-1 was quiet, for what it's worth. Hum that audible seems like a defect. You may want to contact Tom Tutay in Florida, he's the East Coast service center for Air Tight and a really good guy. If you Google his name it should give you contact info. Good luck!
Air Tight ATM-2 mechanical hum.
My new Air Tight ATM-2 emits an audible hum (which can be heard from 3-4ft away, music off) from its power transformer. Although the output at the speaker is fine, i'm curious if this indicates any defect (cuz i expect a dead quiet unit in this $9,000+ price range). Anyone has any input? I'd appreciate your contribution.
Thank you.
Thank you.