Power supply hum transmitted to loudspeakers

I had some transformer hum from a high current SS amp I use for a spare speaker system (for my deck) and a PS Audio Humbuster III completely fixed the issue. I now plug both of my amps into it although my main tube amp is quiet anyway. I demand that my system is humless and it is…I have lighting dimmers here and there and they don't bother the rig, and even my turntable is dead quiet after I put a new din plug Mogami cable on the Akito arm (Jelco or something). P.S. Audio should have kept making the humbusters…they're cool.

I guess a good question is how much noise emanating from your loudspeaker, once your system is energized, is normal? I avoid saying acceptable as we all have different tolerances.  When we place our ears 12 inches from the tweeter or midrange driver and hear a low level, buzz, hum or hiss, with nothing audible at the listening chair, is this normal/expected? When I run tube gear I often hear a low level hiss, with solid state a low level buzz, but no more than 1-2 ft from the loudspeakers. 

A question for Atmashere/Ralph:(and others who care to contribute)

With your fine OTLs and the sensitive loudspeakers you often use, can you hear any noise/hiss 1-2 ft from your loudspeakers at idle? My VAC amps and my AudioNote Kit Interstage Monoblocks both have low level buzz audible 1 ft from my KEF Ref 3's, not particularly sensitive loudspeakers. This occurs when they are plugged directly into dedicated outlets or my Torus isolation transformer. Thanks!

I'd like to share an observation.  Two days ago I moved my audio system to a really silent room that my stepson vacated. The room is extremely quiet but the components are closer as are the loudspeakers.
 Now that background noise has been virtually eliminated I can say that my two amplifiers that I thought were dead silent have minor transformer hum and there is a very minor buzz from my loudspeakers. Perhaps Brian is correct, above, concluding all components have very minor electrical or mechanical noise which should be ignored if not audible from the listening position.  

I can put my ear up to the tweeters in my rig and it's dead quiet, unless music is playing and then it's painful…so don't do that second thing…but try a Humbuster if you can find one. I do tolerate some hum from guitar amps, especially a single ended Class A Burriss Royal Bluesman head I use that has some hum that seems to emanate from my pedalboard…frustrating but worth it as the amp is so good.