Amplifier hum - normal?

All transformers will hum a little but only poorly constructed ones will generate excessive hums. I would consider that a defect if you can hear it more than a few inches away, especially in a modern high-end amp. The propose of a high-end amp is play music in a quiet room. It shouldn't hum at all.

Hmm... I'm not sure what would constitute excessive or normal. I have sensative ears... lol, but I'm sure we all do here.

Idk.

"A lot of modern amps have toroids, which are more prone to humming and buzzing as a result of DC on the power line."

As far as I know Toroid is very quiet compare to non-toroidal transformer. In addition is more efficient because of low stray magnetic field (one tenth of traditional transformer) and higher power rating for the size because of higher flux densities (up to 18000 Gaus vs 14000 Gaus in non-toroidal transformer).

The only disadvantage of toroidal transformers that I know of is cost of winding.

Kijanki,
It seems like you've rehashed what you've read on Wikipedia without getting a proper understanding of the facts. Yes, toroids are generally mechanically quieter than E-I types, EXCEPT when subjected to DC.

The core of a toroidal transformer saturates more easily than that of an E-I type transformer. Because of this, toroids tend to have higher inrush current. DC offset on the power line will also cause magnetic saturation of the core of a toroid more readily than in an E-I type transformer. As the toroid transformer attempts to recover from the saturation, this causes a buzzing sound.

Manufacturers like Equi=Tech and Plitron employ manufacturing techniques in their "Q" type and NBT type transformers respectively that help make them less susceptible to this core saturation.

See here:
http://www.soundstage.com/maxdb/maxdb071998.htm
.

So this humm isn't something that indicates a poor-quality transformer or a malfunction?

A friend used to have an older Crown amp and he said it used to buzz much louder than this Yamaha.

Also, I wanted to add... whatever I have my volume set at makes no difference what-so-ever. With my amp gain all the way down, I still hear the same buzz.