Amplifier hum - normal?


Is it normal for amps to emit a slight humming noise from the transformer when turned on?

I never noticed it in my old integrated that I lived with for over 10 years, but that was lower power. Now I've gone from 50wpc to 120wpc... don't know if that makes a difference here though.

I mean, it's not nearly enough to bother me or even really be audible past 3 feet away... but I am curious if this is typical for amplifiers to do this.
djembeplay
The PS Audio Humbuster III worked pretty well for me. Give it a try, most places carry a 30 day money back guarantee. Not much risk.
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Resurrecting this discussion, if the hum has increased over time (and increased consistently over that period, not ebb and flow), would that pretty much rule out a DC source i.e. more so a fault of the transformer, the fault becoming worse with time?
If you are referring to the OP, I built him a DC blocker that cured his hum problem.

http://img.villagephotos.com/p/2003-5/191557/DC_BLOCKER_02.jpg