Got big amp-help with 20A line and receptacle

Whatever you end up doing, make sure it's up to code.

My electrician installed a pony box off the main breaker box that services my audio components. When I go on vacation or the system is not in use for extended periods of time, I can turn the power off to the entire system at a single flick of a switch without affecting the rest of the household.

With some help from fellow 'goners I had a couple dedicated lines installed a few years ago. Here are some of the important tips I got and follwed:

- if running multiple lines, run the lines on the same leg to avoid ground loops.
- Do not have lines share a neutral bus. Run each line back to the box independently.
- 12/2 Romex should be fine for most applications, and 10/2 is apparently much stiffer and harder to work with, but I guess if you need it you need it.
- Make sure the cable you use meets UL standards and code in your area.
- Run more lines than you think you need, but at least one for analog and one for digital.

This info was super helpful since my non-audiophile electrician had no clue as do I imagine most electricians. I'd also try to find some way to get that dimmer out of the circuit as they seem to be a universal no no for audio as you seem to have already discovered. Not sure what alternatives are out there but maybe someone here has some recommendations.

As for outlets, I used Porter Ports and they seem fine, but I'd be interested in trying the Audio Maestro and Furutech GTX-D outlets as well. Here's a review that may be helpful if you haven't seen it...

http://www.enjoythemusic.com/magazine/equipment/0114/audiophile_ac_outlets.htm

Hope this helps and best of luck.

But some posters here and elsewhere stated that I should have an isolated ground installed outside the house and at least 6 feet from the existing ground.

Bad advice, forget the dedicated earth ground. The earth does not possess some magical mystical power that sucks nasties from our audio gear. The safety equipment ground main purpose is to provide a low impedance, resistive, path for ground fault current to return to the source, the electrical panel.

I did speak with two electricians today, and neither seemed to have much familiarity with the considerations for audio quality that I mentioned to them. Therefore, I would like some input on what to ask of them.

First off it depends on the local electrical code in your state and city what type of electrical installation can be used in your area. The electricians in your area will know what is allowed.

Because you are using an existing convenience receptacle outlet circuit to power your audio equipment I would suggest installing at least two new dedicated branch circuits. One dedicated circuit for the new power amp and one for the other equipment. With two dedicated circuit there is a less chance of a ground loop hum problem. This will lessen the chance of a difference of potential, voltage, existing between the two equipment grounding conductors of the two dedicated circuits.
If it were me I would feed my preamp and power amp from the same dedicated circuit. Use the other dedicated circuit for the other associated equipment.

You said the length of the run is around 50 to 60 feet. Did you figure up and down over and around in your calculation? If not that can add another 20 feet to the length.

IF you decide to plug the preamp into the same receptacle as the power amp I would install #10 AWG wire for this 20 amp dedicated circuit. With #10 AWG wire you won't have to worry about any dynamic power demand fluctuations from the power amp effecting the power being fed to the preamp.

For the other dedicated circuit use #12 Awg wire.

Type of wiring and wiring method used.

Probably the worst type of wiring method is to install conduit then pull the wires loosely randomly into the conduit. This method will assure you ground loop hum problems. Worse yet is to install more than one dedicated branch circuit in the same conduit.

If conduit is used, or must be used to meet local code, use aluminum armor MC Cable. One cable for each dedicated branch circuit. I would recommend solid core wire over stranded wire. MC is made both ways.

If code in your area allows NM-B cable,( Romex is a trade name of NM-B cable), works well providing long parallel runs are kept separated by at least 6 inches to reduce induced magnetic fields of the current carrying conductors from inducing a voltage onto the one another most importantly onto the equipment grounding conductors of the NM-B cable.

Make sure all the dedicated branch circuits are fed from the same Line, leg, of the electrical panel for all audio / video equipment that is connected together by interconnects.

A must read before you call the electrician.
Bill Whitlock, President of Jensen Transformers Inc.
http://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf
Pay close attention to pages 31 through 36
.
Jim

Contact any of the makers of "audiophile" grade outlets (PS Audio, Shunyata, etc.).