While you're at it, you really should consider 3 dedicated audio circuits. With your high-powered amplifier on a dedicated 20 amp circuit your dynamic headroom should just blossom even at low volumes. Then you should have a dedicated 15 amp circuit for your digital source (because of the digital noise induced back into the line) and another for your preamp. Even a low-powered preamp sharing your amplifier's circuit draws just enough to strip away the dynamics. If your electrician can do one, he can do three. He'll just need to double up on a few of the circuits in the service panel. Oh, and if you choose to do this, you should have him connect all audio circuit grounds to the same common isolated ground if possible.
While you're at it, you really should consider 3 dedicated audio circuits. With your high-powered amplifier on a dedicated 20 amp circuit your dynamic headroom should just blossom even at low volumes. Then you should have a dedicated 15 amp circuit for your digital source (because of the digital noise induced back into the line) and another for your preamp. Even a low-powered preamp sharing your amplifier's circuit draws just enough to strip away the dynamics. If your electrician can do one, he can do three. He'll just need to double up on a few of the circuits in the service panel. Oh, and if you choose to do this, you should have him connect all audio circuit grounds to the same common isolated ground if possible.
