New Electrical Circuit

@puffbojie

The electricians have it scheduled for 15 amp circuit.

My guess, the electrician you are hiring is not an audiophile. He is basing his install of a 15 amp branch circuit on bare minimum electrical code. Electrical code could care less how an audio system sounds. Is it electrically safe? Code is satisfied.

Like others have said have a 20 amp branch circuit installed. Slight difference in cost for the wire. Breaker and labor cost no difference. It’s a no brainer imo.

Bare minimum for a 20 amp circuit is #12awg copper. You can have larger wiring installed if you choose.

If the length of the branch circuit wiring is 50ft or longer from the electrical panel to the wall outlet I would recommend #10awg solid wiring. Breaker in electrical panel will be 20 amp. I would also recommend a minimum of two dedicated 20 amp branch circuits One for digital sources and SMPS 120V power supplies, the other for analog 120V power supplies. Reason, it helps decouple the digital 120Vac power supply(s) from analog 120Vac power supply(s).

A dedicated branch circuit... A circuit with a dedicated Hot, Neutral, and EGC (Equipment Grounding Conductor). A true dedicated branch circuit should never be installed in a common conduit or cable assembly with other branch circuits. Current carrying conductors can/do induce voltage from one branch circuit to the other(s). (See Overview of Audio System Grounding & Interfacing Link below.)

If two or more branch circuits are installed for audio or audio video equipment that is connected together by wire interconnects the branch circuits should be fed from circuit breakers on the same Line, leg, in the electrical panel.

2 conductor NM sheathed cable (Romex) is widely used by audiophiles. I used to recommend it to feed audio equipment. I now recommend 10-2 solid copper MC (Metal Clad) aluminum armor cable.

I consider myself a qualified audiophile Licensed Master Electrician.

Reading material:

Read pages 11 through 13.

Integrating Electronic Equipment and Power

Read page 16. Read pages 31 through 36.

Overview of Audio System Grounding & Interfacing

Jim

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@jea48 ​​​​​

Do you normally specify isolated ground and is that why you recommend MC?

@jea48 ​​​​​

Do you normally specify isolated ground and is that why you recommend MC?

@devinplombier

For a residential house I never recommend an isolated ground. It would not serve any purpose what so ever. FYI even in commercial and industrial facilities an IG, Isolated grounding conductor and IG type outlet are seldom used now days. They where big in the 1970s, 80s and 90s. They started fading in the early 2000s.

I recommend 2 wire solid copper aluminum armor MC cable.

Example:

10/2 Solid copper Aluminum armor MC (Metal Clad) Cable

The reason I like MC cable better than Romex is because of the way it is constructed. Hot, neutral, and insulated green equipment grounding conductors are tightly twisted together in a spiral twist and held tightly together by the armor. MC cable NOT AC cable (commonly called BX). AC cable is garbage for feeding audio equipment.

Romex is ok provided care is taken when installing it. Avoid twisting the cable as not to change, distort, the lay of the EGC (Equipment Grounding Conductor) between the Hot and neutral current carrying conductors. That’s next to impossible to do. If you tell the electrician to install the Romex keeping the cable flat without any twists. He will think you are nuts...

Read pages 12 and 13. Note the chart on page 13.

Integrating Electronic Equipment and Power

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@jea48 

Thank you, that makes sense.

Between (a) running 3 separate homeruns to the panel as mentioned above, and (b) a single homerun powering a subpanel in the listening room, which would you recommend?

@jea48 My electrical box is outside. Can they encase the (Southwire Armorlite 125-ft 10/2 Solid Aluminum MC (Metal Clad) Cable) inside metal conduit for the outside portion for weather proofing?