Dedicated 20 amp circuit. 10/2 or 10/3?

@mmenasci 

Just to make sure I'm clear on what you mean regarding having all the circuits on the same "side".  The panel should have a diagram of how the circuits are connected.  The power from each 120 volt leg coming in is distributed using every other position on each side of the main box. This allows a 240 volt double pole breaker to pull from each side. 

One "side" is the red wires and one "side" is the black wires.  Each of these wires to neutral is 120V.  Red to black is how you get 240V.  

You should keep your load somewhat balanced on red and black but the entire audio system will not be a big enough load that it should be split. 

I put in one circuit from each side because it was convenient but not necessary.

Jerry

Another reason to have a circuit from each side would be if you found one side noisier than the other you could plug everything into the less noisy side.

Remember the threads of people trying to find mysterious noises?  switching to the other leg will usually solve that problem.

If the device count is modest and the power low, 10/2. If you want multiple outlets and really want 2 dedicated circuits, 10/3.

Also, consider running 10/2 at 220V to a step down, balanced transformer in the room. If this is a long run this can be especially beneficial.