Slight hum in my amp. Is this normal?


I have an Anthem A5 and when I turn it on there is a slight "hum" if you put your ear close to it. From 3 feet away it’s unnoticeable. It's in the amp, not in the speakers.
Is this normal?
oldschool1
@jea48 , I thought I did. One more try:

DC on the line occurs when 1/2 of the AC line (for example, positive going portion of the AC waveform) is loaded while the other half is not.

Space heaters or hair dryers on half power do just exactly that. So one half of the AC line can have lower amplitude due to the loading as a result.

But its still an AC waveform and so can travel through a transformer. But the output will still be asymmetrical. The asymmetry can be filtered out by a DC blocker which is a simple circuit consisting of 2 or 4 diodes that are bypassed by some large capacity electrolytic caps.


Go under chassis, remove the transformer screws, apply some blue tac or similar substance to the holes and re-tighten the screws. It will lower transformer noise.
Received the Emotiva  CMX-2 which made no difference in suppressing the 60 Hz hum (clearly heard thru my KEF Q1 monitors 12 inches away).
No source was connected, hum did not vary with volume and mute button made no difference. I've given up hope of using this integrated with my Klipsch LaScalla IIs. I'll be content using my BAT VK-300se 150 wpc integrated which is dead silent. Sometimes you get what you pay for...