Dedicated power

I forgot to mention:

The most common cause of systems sounding harsh when you turn them up is often room acoustics. Sit up close to your speaker and see if it sounds much less harsh.  If it does, it's your room.

Best,

e

You may add additional ground rods to the original circuit however.

That is correct.  It's the use of the word "isolated" that worried me.  You may add any number of ground rods, so long as they are bonded to the same ground that is bonded to neutral at the service entrance.

FYI, You may not use a ground that is electrically separate from your service entrance ground.  Doing so violates the NEC and is a safety hazard.

You may add additional ground rods to the original circuit however.

Well, I think this is overkill, but the suggestion I gave you was exactly what I did for my workshop, running 1 1/2 HP and 2 HP motors. :)

In the basement, the NEC let me run 8 gauge (was it 6?? It was a long time ago) Romex with nothing more than nailed on brackets. No conduit needed. Ran it to a sub panel on a 60 A breaker, and distributed 10’ runs from there.

Could I feel a difference while cutting wood? No... but it was much easier to install this way, and the 4 or 5 dedicated circuits could be run more easily.

How long are your runs?  Unless they are more than 30' you are just as well running 12 gauge Romex.

If much longer, then run a 60A to a subpanel, and then run short 20A circuits to each outlet.  The advantages of a 60, in addition to lower voltage drop, is that the code may let you get away with not running conduit for it. Check your local ordinances.

Never put more than a 20A breaker on a normal 15/20A outlet, regardless of wiring. It has no audible benefit, and serious safety issues.