Very often two dedicated circuits are used; a high powered amp in one line and sources in the 2nd line. Or line 1 is used for analogue components and line 2 for digital.
To clarify, your second circuit is a shared AC line? Do you know how many other circuits and what devices are on this shared line?
It's important because you don't want your audio sharing a line with appliances or dimmer lights that add noise.
If the current draw of your amp isn't too high, then you can plug the entire system into the dedicated line. You have 20 amps to work with. Source components draw very little current.
To clarify, your second circuit is a shared AC line? Do you know how many other circuits and what devices are on this shared line?
It's important because you don't want your audio sharing a line with appliances or dimmer lights that add noise.
If the current draw of your amp isn't too high, then you can plug the entire system into the dedicated line. You have 20 amps to work with. Source components draw very little current.