@steeveb @jea48 >>>The two hot conductors must be fed from opposite legs. One from Line 1 and the other from Line 2.<<<
Even though steeveb failed to mention that in his post (I’m sure he just forgot), it would be a must in the 3-wire hookup that he described. You would never ever want to have two dedicated 15 or 20 amp branch circuits, on the same leg, sharing the same neutral (unless it was over-sized, but don’t even go there).
Here are some great white pages put out by Middle Atlantic. Pay special attention to Middle Atlantic’s page 12 of the booklet (AC-HCF). If you’re looking to wire up a branch circuit for audio, AC-HCF is the wiring I would highly recommend using. Obviously some, due to existing building construction, won't be able to utilize this particular cable, but if and when possible, use AC-HCF (with isolated ground outlets) for your audio branch circuits, as it just doesn't currently get any better. Taking that even a step further, it would probably make sense to have a separate dedicated branch circuit just for your power amps, and one for your front end gear.
Optimized Power Distribution and Grounding for Audio, Video and Electronic Systems