Power questions

Hello all.

New enthusiast here.  My question is about source power for my equipment. Im redoing the wall that my equipment is on. I use it for 2 channel and movies. Purpose is to increase distance between my left and right speakers and to get a larger tv. As an electrician, when i origionally roughed the wall I knew enough to pull a dedicated cct for the "entertainment system".  I never envisioned getting sucked down this worm hole. So...being that the wall is open i can easily pull another dedicated circuit. Perhaps #10 awg. So i would have 2 dedicated 20 amp ccts on the wall and a 15amp general purpose cct.  My equipment is as follows: Anthem mrx740 avr, Anthem 325mkII amp, Paradigm Founders 120H left and rights which have active woofers , a node streamer, and a Rell wireless module.  Behind the wall is the router for the house(stair case wall).  The amp powers my lcr speakers. The avr powers my surrounds. Questions are:

1. Would another cct make sense?

2.  How would equipment be best devided between the ccts? (I know this should probably be obvious but amuse me please)

3. Would pulling a dedicated neutral be better than sharing  a neutral as far as noise reduction?

4. Isolated Ground outlets?

Thanks for any input 





2012 Seminar w-Notes v1-0.ppt - indy-aes-2012-seminar-w-notes-v1-0.pdf

Check out page 16. Read pages 31 through 37.


A true dedicated branch circuit does share a neutral with other circuits. (Therein a multiwire branch circuit.) A true dedicated branch circuit does not share a conduit or cable with other branch circuits.

For the new 120V branch circuit I would install solid 2 conductor with ground MC aluminum armored cable. NOT AC armored cable.

Solid copper wire. Not stranded wire conductor MC cable.

Just my 2 cents...


The biggest issue I foresee is having different grounds for your processor vs. your amp and sub amps.

So,  very unpopular opinion, I'd run 12-3 or 10-3 to run a multi-wire branch circuit (i.e. split neutral).

I'm also not a huge fan of running 10 gauge wiring, mostly because a little inductance and resistance between you and the panel reduces noise from elsewhere, but if you have a very long run and anticipate high currents it can be better.

Another possible alternative you should consider is using 6 gauge Romex to a sub panel in the room. 

Thanks guys. Thanks for the link jea48. It was informative. I do have to tell you though that dedicated ccts do indeed often use separate neutrals,  sometimes they are even upsized.  At least in data centers and mdf rooms.  25 yr commercial/industrial electrian here. The term "branch" refers to ccts after the main of a panel. When "branch" ccts share a neutral its called networking. Networking is becoming less common because of the inherent safety hazards associated with it and the code requiring networked ccts to be disconnected simultaneously in instance of a fault or overload. So 2 ccts sharing a neutral would have to be terminated on a 2 pole breaker.  3 ccts on a 3 pole. 

My curiosity with the grounding is that ive installed isolated ground receptacles in hospitals and for data racks for sensitive equipment so why not for audio?(Side note,  we use conduit in my area.) An IG receptacle would separate the ground path of my equipment from the grounded conduit in theory reducing noise.  Make sense?   


The issue with a hospital vs. audio is not the plug, it’s the grounds. AFAIK, hospital gear doesn’t connect to other hospital gear in a daisy chain.

The signal grounds in audio however may go from device to device. So, sure, use an isolated ground outlet if you want, but having your processor be several feet from your amps in terms of ground wiring distance can cause issues. Best to use a star grounding system, where they all meet in 1 place near the equipment than 20’ away.

Of course, you can always use non-metallic outlet boxes, making the whole question of an isolated ground moot.

I do have to tell you though that dedicated ccts do indeed often use separate neutrals

Agree, a true dedicated circuit does not share a neutral with other circuits.. Therein a multiwire branch circuit.

Multiwire branch circuits are not considered, IMO, as true dedicated circuits. If a 3 wire multiwire branch circuit is installed to feed an audio system, that’s not two 120V dedicated circuits, imo, that’s two 120V separate circuits.

Multiwire branch circuits, as a rule, are not recommended for feeding audio systems that are connected together by interconnects. When more than one branch circuit is used to feed audio equipment, that is connected together by interconnects, the circuits should be fed from the same Line from the same electrical panel. Therein residential split phase 120/240V all from L1 or all from L2. Not from both L1 and L2 though.

Also as you know only the unbalanced load of L1 to neut and L2 to neut returns on the shared neutral to the source. As you know the balanced load(s) of L1 and L2 are in series with one another and are being fed by 240V. So the garbage, hash, being fed back out on the power cord of a digital piece of equipment using a Switched Mode Power Supply will be dumped, fed, in series into the power cord of the power transformer of a analog preamp or power amp. Noise? You are better feeding all your equipment from one 120V dedicated branch circuit.

/ / /

From an old 2019 post of mine.

Why install all dedicated circuits on the same Line, Leg?

"Less than 300 microamps of ground loop current can cause hum as it flows in an unbalanced audio interconnect cable. However, harmonics of 60Hz that are generated from lighting dimmers or switch-mode power supplies sound like Buzzz mixed with a bit of Hummm and are more easily coupled by even smaller currents. Harmonics can add together when equipment is powered from different phases, so clearly there is an advantage to specifying same-phase electrical service to power the electronics systems in most cases....

Any leakage currents on the safety ground wires of split single phase load circuits fed by different phase legs will add together due to the 240V potential difference....

Power conditioners do not solve any of these common problems: Cross phase coupling (doubles hums & buzzes) .... What actually does solve them: Same phase power.


Split Single Phase electrical service is most commonly found in residences and smaller commercial buildings, and is commonly used to feed AV equipment. One key advantage that single phase has over three phase is that while harmonic currents are still present, it is not possible for the �triplen� components to add in the neutral. In addition, use of split single phase can result in at least a 6dB reduction in noise floor as compared to three phase if the capacitances of the connected equipment are relatively well balanced. However, any leakage currents on the safety ground wires of split single phase load circuits fed by different phase legs will add together due to the 240V potential difference."



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Yes, im in the chicago area. I wouldnt have. Problem running mc cable or romex just cannt get it to where it needs to go without major ordea.  I can however make the conduit run dedicated.  Thanks for everyones input. Great advice!!

Don’t confuse neutral sizing for commercial and industrial with neutral sizing for residential. (Commercial/industrial is 3 phase with neutrals that are almost always shared, and powering single phase loads can easily result in overloading of the common neutral. Also in residential (single phase) shared neutrals are dangerous, illegal in many markets and often cause problems when load imbalances occur)

As stated earlier, if you want more than a couple circuits in your media room, pull 8/3 or 6/3 and install a small subpanel.


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Consider an isolation transformer beside your main panel. It made as much difference in my system as an upgrade of a major component.

But they can be noisy, so best sited away from your living spaces. Also eliminates need for special power cables - I experimented.

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Good summary jea48. 

Unfortunately terry, iso xfrmr not in budgit unless I come across one on a demo job. For now im doing 2 dedicated 20amp ccts. One for my active paradigms and 3ch amp and one for avr, streamer, node etc...

Any thoughts on power conditioners?  Do they make an audible difference?

Any recommendations?