how to run a 230 volt line from my panel??

With regards to the breaker; Yes, a 20A/230V breaker will provide you with the two phases & terminals needed for your run. I'm assuming that 12AWG wire is a dedicated run for your 230V circuit. Wait until you receive the component, find out what configuration the plug is(depends on the country) and get an outlet to match. The option would be to obtain a NEMA 6-20(20A/230V) plug and outlet, then install the plug on the unit's cord. You DO NOT want to run 230V to NEMA 120V outlets. At some point- someone may plug an appliance or component into it, and toast it, or get shocked by the(then hot)chassis.

You'd need to run a new line from a new 2 pole breaker in your panel to a new 220Volt outlet in your stereo room.

A 220Volt outlet has a different pinout than a 110V one the left pin is horizontal if mounted with ground towards the bottom. Do not wire a 110V outlet with 220V as you could accidentally plug a 110V component into it .

I'd recommend CLEARLY marking the back end if any IEC cord you use too thus avoiding plugging 220V into a 110V component, the back end of power cord look identical.

I have both 220V and 110V outlets in my music room, If you have any doubt how to do this have your local electrician do it for you.

Best of luck

Peter

If you are intent on doing this then get an electrician in. There could be MANY code restrictions that need to be followed.

In north american homes 230v is generally reserved for stoves and in some cases heating.

Connecting a 230v component to another of 120v may also present a problem.

Best solution - get a steup transformer - at least they are designed for the job.