Urgent Help: Wire for dedicated lines???

Bundus is right on about wire choice.I've done exactly as he describes with excellent results.The electrician should know that a separate ground is against code.The reason it's not a good idea is with two ground paths any overvoltage can find it's way back through your equip.isolated ground.Also two ground potentials is the biggest source of ground loop hums ect.Unless you had a separate service feed from the utility transformer and panel grounded to a new rod for your audio circuits the best way to handle your grounding is to suplement your existing service ground with an 8' electrode driven at least 6' from any existing rod and connected in parallel not series to the same lug on the grounding/neutral bar in your panel.Have the electrician connect your new circuits isolated ground wire as close as possible to this point and you will have a star grounded low impedence ground path.This is what I did and the noise floor is much lower....Good luck!

To follow up....If your using metal conduit and boxes for your new circuits make sure that your electrician DOES NOT bond your new outlets to the boxes via any jumper wire.Doing so will defeat the isolated ground on your hospital grade plugs.The goal is to keep your audio circuits ground path separate from your house wiring.The reason being is if your house uses metal boxes with bonded outlets ,as many modern homes do,your metal conduit via it's connection to your bonded panel enclosure becomes part of that ground path allowing stray voltages to make there way into your audio circuits.One advantage of the metal conduit in this set up is that it acts like a shield in many of the better power cords where the shield wire is connected at the load end ( or your panel in this case) only.Same principle at work here......

The best dedicated circuit you can run is, By using 10awg shielded belden cable. Me and my friend wired up his home theater with romex orginally and though that it could use some improvement. So we shopped around and found this
10 awg. Belden cable that had high purity copper and it was shielded. It already had a jacket although we still had to run it in Flex conduit because of code . This is the single best upgrade anyone can do to there system. It elevated the whole system by a wide margin.

Infwgf, do you know the part number of the 10awg shielded belden cable and where can I find it? Is it available on website?
Thanks
Tran

what's a THHN