Regarding issue I am experiencing currently ..
When I power on the AVR I get an initial "oomph" surge sound. Than as the machine completes its startup process I get a loud mechanical "thud" followed almost always by (simultaneously) what I a can only describe as a "slight pop" from the speakers..
I had a 5 channel amp (dual power supply is my understanding) but the hum although somewhat tolerable, certainly wasn't ideal if one enjoys a quiet background noise. I had a dated matching processor that I was disappointed when hooked up as it really caused the setup to buzz, hum loudly (like the sound of a microphone feedback) ... not good.
So I reverted back to just the AVR only. I get the sounds as mentioned above in startup.
I only assuming really that dedicated 20 amp lines will eliminate all this background noise and give me plenty of power to draw down on for my multichannel amp that's sitting idle.
I bought a Torus IS15 thinking that is may help control my power and give me a better sound. To be honest, it did help giving a better sound in the pure sense of the word. But...doesn't seem like it helped much to clean up the hum, crackle, pop ..
Hmmm...gee I always thought there was a transformer outside my home. Never really thought about it. Looking outside, there is no transformer on the pole beside my house, or the neighbours. Peering up the road I do see a "smaller" transformer that I guess there are 4-5 or more homes sharing. Hmm..
I can't recall any noticeable changes in the homes power, or draining or power. Not regularly anyway. To be honest what does come to mind is sometimes the power will cut out, amd turn back on shortly after. Like a brownout I guess, if that's the right term. Nothing lately though....maybe there was some work being done in the area at the time.
Only other think I may notice is the speed change in the fan I regularly run in my other room. Ya know...the fans steady, than ill hear a mild drop in the fans operation.
Overall I think the power is fine coming into the home. No issues...just a few normal occurrence at times, rarely.