Amplifier hum - normal?

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.

Gbart

Thank you - that was very informative.

Only black from my Yamaha MX1000 U. It's both very high wattage and vintage.

Really? Hmm... Your not referring to noise coming through your speakers, right?

Djembeplay, hum can come from things like loose transformer laminations, loose mounting bolts, other internal issue, or DC. Trying to do an accurate diagnosis on the Internet is difficult and the best that can be done is to offer suggestions.

You need to go through a process of elimination, IMO the first and least intrusive step being to rule out DC. Try disconnecting devices/shutting off breakers to see if a connected device is the cause. You could also try the amp at a friend's house to see if the hum persists or goes away.

If you are still getting the hum, the next step would be to remove the amp's top cover and check for loose mounting. In the end it could just be that the transformer is noisy. If DC is the cause, there are solutions that include eithar a manufactured or DIY DC blocker.