Dedicated 20 Amp Line for Audio

14awg is the MINIMUM you can do for a 15A circuit.  If it's a long run, then 12awg is recommended.  That is based on electrical code requirements. 

However, there is a definite difference in current capability between 14awg and 12awg romex, even on low current source components.  I've tested this in my room when I tried 14awg romex to my preamp/processor.  It just did not sound as open and the sound did not hit with as much authority as when I did a 10awg romex. 

You can use 8awg, but you are only going to get stranded wire and you will need to run this in conduit (per electrical codes).  Only romex can be run bare through walls and in ceiling/attic.  I would rather have solid-core 10awg or 12awg romex than stranded 8awg (but there are others with different opinions).

auxinput - thank you. I am kind of narrowing this all down with the help of you and the others that have so kindly posted here!

I am currently in the process of doing this wiring and in fact just today installed the 20 amp breaker in the panel and pulled and tacked the 8-gauge from the box up through the attic and to the wall where it will come down to the entertainment center.

I still need to come down through the wall and will probably just cut and remove the old 15 amp wire and use that as the wire pull through the wall.

All plugs are 20-amp hospital grade (with the green dot) and will accept the 8-gauge wire.

We have solar panels and an inverter. I’ve heard that these can add noise on the line. I put a ferrite bead over the wire right where it comes out of the panel. May not help anything..., but couldn’t hoit.

I recently had a room built for audio only (18 months ago? how time flies). My audio conscience electician wired a 20 amp dedicated line (less than 20 feet from the box) to a single outlet. I have a conditioner/distribution unit with all electronics hooked into it. My lights and electrostatic speakers are on a separate new line.

Happily, my house is the second one from the local transformer and I live in a residential neighbourhood far from any Industrial or Retail complex. Very little to zero line noise.

I am happy....

I ran 2 dedicated 20 amp lines with 10 ga wire from my breaker box.  Using some audiophile plugs.  The run is about 65 feet so opted for the larger guage wire.  If you can run dedicated lines, you won't be disappointed.