Dedicated power circuits

it is not the end of the world, but, all lines on one leg is not accurate or necessary.

Make sure you have dedicated lines to the panel.  In other words, each hot, neutral and ground wire goes back to the panel directly and isn't shared by any other circuit.

Each piece of equipment converts the AC voltage to DC internally, and they should have adequate noise filtering internally.  Ground loops (hum) typically occurs when neutrals or hot is shared by other components and is not adequately filtered.

When the neutral has an actual voltage present over the ground level, then yes, you will have a ground loop problem.  This is why the grounding schemes within each component is very important.  You have nothing to do with that, but some designers (not typically anymore) don't design the ground schemes adequately.

You want to avoid putting components on the same legs as noise making components, like noisy lighting systems, etc.  Large motors, etc.

Most if not all adequately designed electrical home circuitry have balanced loads on each leg.  That is code.  So placing a large load on one leg unbalances the system and causes problems.

My system and many that I have helped put together for others have circuity on each leg and there is absolutely no problems at all and shouldn't be.

I'm an Electrical Engineer and also a Power Engineer (analog/digital design) for Aerospace and a Power Engineer for an Electrical Utility for over 45 years.  I design and build amplifiers, filters, etc. also.

I'm not trying to piss anyone off, but the "must be on the same leg" thing, is not accurate.  Just avoid or remove noise making equipment.

Also, I have noticed that it is a good idea to have the small signal equipment (CD player/transport, DAC, Turntable, Pre-Amp) connected to a decent power conditioner and then to a dedicated line and the amps connected directly to dedicated lines.  This is why I always recommend at least three dedicated lines and not two.

If you have more than one amp, then in my opinion, they should be on separate dedicated lines and the small signal equipment connected to the power conditioner and then to it's own dedicated line.

If you have amps that are basically arc welders, then putting them on the same leg is not a good idea electrically.  Anyway, your choice.

I try to plan for the future.  Start with one stereo amp, then yes, two dedicated lines.  But, what happens when you decide to upgrade and go mono amps???

Have fun in your goals and enjoy

@minorl +1

it is not the end of the world, but, all lines on one leg is not accurate or necessary.

Make sure you have dedicated lines to the panel.  In other words, each hot, neutral and ground wire goes back to the panel directly and isn't shared by any other circuit.

I agree 100%!​​​​​​​

Mike

I disagree with most everything Minorl says. 

Keep it all on one leg. It matters. It not about the noise. If you have a good system, say AR Ref amps and an Esoteric CD player, you will hear it.  It will be more clean and clear.  If you have a Cary SLI80, you might not hear it.  But you will still notice a 10AWG dedicated circuit vs a 12 AWG feeding the rest of the living room.  

I also have not been able to validate putting lights or motors on the same leg as audio is detrimental. The noise is also on the neutral. You can’t hide from it.  I have tried this on many systems before I gave up on it because no one ever heard it.   Make sure to use a quality dimmer such as a Lutron Maestro. That will filter most of the noise.  I do put motors on a separate leg to reduce startup voltage sag on the audio phase.

I do like a good filter. But the only one I have found to work to my satisfaction is a large Torus transformer that has everything on it. Including your modem, router and switch if you stream. I don’t like most other filters. They either collapse the sound stage or create an artificial "Black".

If you don’t want to filter your audio, you segregate your power with subpanels and you filter the noise from your house. But what are you really doing. Not much unless your off grid "Island".  And if your off grid, I am still going to suggest you put a Torus onto the circuits feeding the audio to filter the inverters high frequency noise. As well as any RF that is attaching to the power wiring. If RF is attaching to the phono cartridge, tone arm wire or case of the phono stage itself, you cant do much other than get a good phono preamp that is good at rejecting the noise and not letting it modulate into the power supply.

If you happen to have a very large estate with pools and fountains, security systems, a server farm and a high end audio system, then segregating power and filtering the noise from getting back to the audio becomes something to consider.  You probably have a dedicated utility transformer so your filtered from the street noise.  You may want PFCC attached to a subpanel feeding the motor loads.  You may want a UPS attached to the server farm and security system.  You may want critical power with battery backup for light and refers in power outages.  Most people don't have this.  They share power with 5 neighbors on one transformer.  Your getting all the noise from their dirty devices.  So trying to segregate and filter your own dirty devices is a loosing battle.  Your best option is to filter the line to the audio equipment.

I have two dedicated circuits using MC 12 AWG.  Each branch is less than 40 feet long.  One feeds the front end and one the mono amps.  Originally, I had the two breakers side by side, ie. separate legs.  Somewhere in these forums I read that it is better to have the dedicated circuits on the same leg.  So I moved one breaker one space apart from the other which puts both circuits on the same leg.  I think the stereo sounds better.  Could I discern the difference in an A/B?  I’m not sure.  

The two mono amps are pulling 740W, the front end is pulling up to 500W if everything is turned on.  That’s 10 amps on one leg.  (Same as running a microwave oven).  I have a little voltmeter plugged into one of the dedicated outlets.  It shows 120V right now and did not change when I turned everything on.  (It does not show tenths of a volt.). Right now it is cold and all three heat pumps are running.  I normally see 122V.

That’s right, I just turned my stereo on at 6AM.  I’ll listen to some morning music until the weather warms up outside.  Retired living yeah!