Dedicated lines

CKoffend, wire/cable cannot be type NM and MC at the same time. You must have misunderstood what the electrician told you. Type NM (non-metallic) is your typical Romex. Type MC (metal clad) is armored cable. The armor may be either aluminum or steel. There is no standard wire/cable with "purer" or "less purer" copper. The only advantage to hospital grade cable is that it has an insulated ground wire which serves as a redundant ground. The metal casing of standard armored cable normally serves as the ground.

What was installed, based on my reviewing the runs, was inside metal conduit (which i believe is code in my area considering how it was run - semi exposed in a "crawl space" ceiling. There were 3 wires + - ground.

You are right though, that I could have very easily been confused as to the NM/MC as we/he discussed both during my conversation with him.

What was installed, based on my reviewing the runs, was inside metal conduit (which i believe is code in my area considering how it was run - semi exposed in a "crawl space" ceiling. There were 3 wires + - ground.
08-18-09: Ckoffend

There were 3 wires + - ground.

Four individual insulated conductors? More than likely THHN/THWN insulation......
Like 2 hots, 1 white neutral, and 1 green ground conductor?
If yes, you have a 3 wire multi conductor branch circuit. Two separate circuits with a shared neutral. Not 2 dedicated circuits.
Not particularly good for audio equipment connected together by ics.
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No, three wires total, one plus, one minus/neutral, one ground.