One dedicated circuit for each mono block?

AudioMan58

Lots of interesting things you're saying here, what do you mean by use of brass?

I guess the outlets are really important to have gold plated. What type of electrical wire are you running between the panel and outlets?

In the US very difficult to use a breaker that goes Beyond what the panel manufacturer recommends, stay loyal to the brands, don't use generic crap.

Carlsbad,

Are you saying that the dedicated line you're using for stereo is helpful to your system? Thanks

"NASA announces first audiophile on Mars complains about latency....'

If your monoblocks are 400 watts output or less per channel, one 20 amp line is good.

You are managing 3 issues here:

1) Adequate voltage and current the handle your requirements. A Dedicated 20Amp circuit will do that if the total drwa is under 1KW per amplifier (12 V X 8A = 960W)

2) Grounding. Typically a single circuit has fewer potential grounding issues than multiple circuits, as there are more opportunities for voltage differentials.

3) RF Noise Pickup. Wires are antennas and exhibit capacitive, inductive and resistive components. Improper connections and corrosion can act a rectifiers. Put those pieces together and with a bit of bad luck, you have an RF receiver. Series inductors are low pass filters as are parallel capacitors. Ferrite beads around conductors also also can act as low pass filters. 

Whether some combination of those factors cause an issue in your system is highly situational. Maybe, maybe not. I have experienced everything from mystery hums from Grado cartridges on certain turntables to picking up local AM stations on the sound system for a 20,000 seat coliseums, all due to power and grounding issues.

There is never one perfect way, there is only what works in your situation. Engineers spend vast amounts of resources trying to prevent products from experiencing power related issues in the first place, and it rarely pays to second guess them.