comparison of different dedicated AC line types?

Im getting ready to move my audio system to another part of the house. I'm wondering if anyone has had any experience in comparing a regular dedicated 12 Ga romex line feed to a greenfield (flexible metal conduit) dedicated 12 Ga feed line? Also has anyone tried to terminate a dedicated line with an IEC and plug it in direct to your equipment?
Have no experience with "greenfield" conduit. At one time I did directly wire 12ga. romex to my system power strip, bypassing the duplex - just to see if there was a difference in sound with and without the (regular) duplex. Indeed there was. Much better harmonics and overall sound without. Listened that way for a month or 2, but decided to choose an upgraded duplex due to the fact that if my house burned down for any reason the insurance co. would then have grounds to not honor the claim - even if the missing duplex itself was not found to be the cause of the fire.

But, in general, I've since come to understand that ALL connectors are, sound quality-wise, to be considered the spawn of satan...duplexes, light switches, dimmers, audio and video component connectors, speaker connectors, circuit breakers....wherever a wire is interrupted there is the potential for sound quality loss.
I've run 10 and 12 gauge both romex, Greenfield, and a several others such as THHN wire twisted and pulled through conduit in my eight dedicated outlets. One of my 10 gauge twisted THHN wires were even cryogenically treated in deep submersion.
To be honest I don't notice a difference in sound bassed upon what I described above.
I have tried a number of different high end audiophile outlets, and I do detect changes in sound with them.
I'd suggest you run whatever is the easiest for you that meets your code in your location.
if you won't find anyone done the exact comparison, you can do that on your own hiring electrician and requesting him to provide a couple of different dedicated lines that you're gong to be experimenting with. make sure that he doesn't take you as a nut case tho.
Thanks for your responses. I am capable of running the wiring myself as I was a mechanical contractor.
Thanks to Lak as you have done what I was interested in. I think I will run two different ones to see if I notice any difference in my setup, then go from there.
I would run 10GA to an amplifier.
It's an AC line. Nothing special is required. 12 GA should be fine unless you have very large amps. An AC power line is a noise source, so it is silly to shield it.
The whole point of an audio equipment power supply is to stabilize and clean the power to the electronics. If you have adequate current carrying capability, you are fine.

Speaking from experience with a friend who went through numerous steps upgrading his dedicated AC line, solid core is better than stranded. Improvement achieved going to !0ga replacing 12ga, and additional improvement going to 10ga Cryo'd Romex from VH Audio (no affiliation) replacing the standard 10ga Romex. Also, better to have at least 2 lines, one for analog, and one for digital. He was not using a very high power amp, but a high quality 60 watt pure class A.
I think I will run two different ones to see if I notice any difference in my setup, then go from there.
04-30-15: Jadedavid

NM-B cable (Romex, is trade name of).

Solid core
MC cable.

Pay close attention to pages 31 through 36.
Thanks, that's a great article!
I run a dedicated 20 amp line into a Hydra two for my digital gear.Another 20 amp dedicated line directly into a Guardian 2 for my analog gear.No problems just use good quality connector.

The advantage of separating the digital from the analog is worth the extra effort.
Electrician I hired was told to get that what he (orange)10 guage line from home depot.Same stuff was his reply...

by the way cool article and thanks for that jea.

Hugh improvement though...easily worth the money spent

Electrician I hired was told to get that what he (orange)10 guage line from home depot.Same stuff was his reply...
06-13-15: Digsmithd

Romex, Home Depot.

Southwire, Romex.


Cerrowire, Home Depot.


I doubt if there is an ounce of difference between the two manufactured brands. Note it appears Home Depot sells the Romex brand in a 100ft roll and the Cerrowire brand in a 50ft roll. You may have only needed 50ft or less. That could be the reason the electrician bought the Cerrowire brand instead of the Romex brand.
indeed jame's...enough for two 20amp line's...bada bing.