Dedicated 20 amp circuit. 10/2 or 10/3?

Dedicated 20 amp circuit.  10/2 or 10/3? 

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Ok. So each dedicated circuit should have 10/2. 
I watched ps audio run 10/3 and said they were doing a double ground?

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I plan on running a dedicated circuit for each device. Amps, preamps, subs, etc. 

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Considering the cost of copper, etc., the materials cost of your project are not exactly cheap but the labor is probably more expensive.  It will be easier to run both lines at the same time, which should reduce your labor cost compared to running one and then deciding later you should have run two.  I have three dedicated circuits to my audio area and all three are on breakers next to each other on the same side of the panel.  I do not regret using 10awg wire, even though the circuits are each only 20A.

That's my other question.  Which side of the panel should I use? And should I place all my dedicated circuits on the same side?

Lets think about why a dedicated line was conceived and what it is used to achieve. A dedicated line does the following in my mind:

1. Ensure that your audio system has more than enough power to handle a big amp pulling pulses of high current for bass notes and dynamic sections.

2. Ensure that the circuit is not shared with noisy items like washing machines etc with motors that start, lighting circuits that may have noisy dimmer switches, large resistive devices like hair dryers, irons, and heaters that can impact the shape of the sine wave, etc.

Note that we aren’t trying to protect the audio system from other things on the audio system. Exceptions might be: cheap power supplies for accessories such as ethernet switches, TV, TV streamers, wifi mesh hubs, etc. That is why I thought maybe you want to put in 2 lines, one for pure audio equipment and one for potentially noisy support stuff.

But I’m not convinced of the value of putting in dedicated line for each component. I guess it won’t hurt but I didn’t do it and I wouldn’t do it.

Effectively you’re moving the node where all the stuff ties together from the outlet behind your audio system to the breaker box, perhaps 50 ft away.



Just to make sure I'm clear on what you mean regarding having all the circuits on the same "side".  The panel should have a diagram of how the circuits are connected.  The power from each 120 volt leg coming in is distributed using every other position on each side of the main box. This allows a 240 volt double pole breaker to pull from each side. 

One "side" is the red wires and one "side" is the black wires.  Each of these wires to neutral is 120V.  Red to black is how you get 240V.  

You should keep your load somewhat balanced on red and black but the entire audio system will not be a big enough load that it should be split. 

I put in one circuit from each side because it was convenient but not necessary.


Another reason to have a circuit from each side would be if you found one side noisier than the other you could plug everything into the less noisy side.

Remember the threads of people trying to find mysterious noises?  switching to the other leg will usually solve that problem.

If the device count is modest and the power low, 10/2. If you want multiple outlets and really want 2 dedicated circuits, 10/3.

Also, consider running 10/2 at 220V to a step down, balanced transformer in the room. If this is a long run this can be especially beneficial.

10-4 that is what I had installed.

my friend is a master electrician and Audiophile 

you have live ,neutral and 2 grounds a common ground ,and a insulated isolated ground in its own conduit , then has its own smaller buzz bar the 20 amp 

breakers are industrial silver over Copper which means like regular breakers that are copper should be replaced every 4-5 years because of oxydation,

and use gold plated Copper outlets ,  breakers were made by Siemens Germany 

I tried getting them for my friend very hard to obtain since covid.

underwood Wally has a plug in device Puron ,buy the better ones with the Furutech 

gold copper $350:, the cheaper ones $250 and 3x less conductive Brass, check them out they truly clean your line further ,even if you have a very good line conditioner.

I have a 20 amp dedicated line and I believe it’s its a 12/3 cable on two duplex boxes.  One has the power conditioner on it and the other has the amps plugged into it.

 I haven’t changed outlets mostly because if I ask five people about it, I get five different answers.

One can run 10/3 romex for 220 single phase to a location, and run with it a 12g. green ground with it.  Perhaps not 'according to Hoyle' but at the business end one can 'split' into 2 - 110 circuits and still have the 'safety' mechanical ground....

Label what you've did/ each end.....

It's not nice to 'leave mousetraps' like that, and keep your amp loads balanced.

Cooking one side generally takes the other with it...just to make the point....;)

Oh...and if you move/sell and/or bust the lease with your 'loud *ss music'....restore it to a 'normal' 220....With the correct f/m plug....

For most folks, a 12/2+G or 10/2+G run from the 'quiet' side of the panel is perfectly adequate. If you have big power hungry monoblocks, then a 10/3+G providing 2 circuits is still more than adequate. 

In an existing house you may not have panel space or the luxury of picking a 'quiet' side of the panel and electricians rarely leave service loops adequate to rework loads by re-homing breakers. In that case an solation transformer although hugely expensive may be worth it to you. For most, good power conditioner will have to do. 

In any event, a digital oscilloscope, preferably with spectrum analyzer capabilities is really the only way to see how clean or dirty your power actually is. 

I have a pair of class A mono blocks, I ran one 12/2 conductor twenty amp circuit to a Cardas 4181 receptacle. From the wall the power cord goes to the power conditioner, then all my gear plugs into the PC. Running full load with some volume, I am pulling 9 amps of current . Not sure what your gear is? #12  is adequate for most systems. But run cable for where you will end up.

Keeping all the audio on one leg helps reduce ground loops. Your system is probably not going to draw enough current to need both legs.

Circuit breakers at the Bus? If you are running a dedicated breaker for each piece of equipment (you are going to need some 2 and 5 amp breakers, and with no AC motor loads I would ask why have a separate circuit for everything?... I would first consider a sub panel to save on all those copper runs (and to prevent leeches, or "other" circuits invading), then yes alternate between the bus (legs), or left side right side in the panel, and try to keep the loads balanced, and the circuit breakers and wires correctly sized for the designed load ("over sized" circuit breakers and wire is not a CURE for anything). Any 220V breaker will already be feeding from both bus bars. Chances are good that your main panel is presenting an unbalanced load now. If a sub panel is separate (downstream) from the main service, through a  fused disconnect and a sub panel main breaker, I would consider Isolated Ground Outlets, and possibly (if the current NEC allows) a separate grounding systems for that sub panel, or at least those outlets.  A more extreme$$$$$ (but effective) measure would be a complete new service, much like Fremmer did at his house (see his videos). But please consult a Master Electrician, I have not professionally practiced since 1994, and am not familiar with current (lol) code.. The National Fire Protection Assoc. publishes the updated National Electrical Code, and licenses professionals in an attempt to keep us folks from burning, or exploding, things and those we love and cherish.

I made all the stupid mistakes with power that are possible, including not checking the electricians work when he set up a reversed neutral one of the times they wired my room. 

I have a large house with sub power panels, I didn't take my home run lines to the main panel but to a sub panel. Stupid I know. But then again if I did go to the main power connection to the house that is still a sub branch of the power on my street and in my part of the neighborhood. So I bought 2x power reconditions PS Audio P20s and I already had about 5 different kinds of old power conditioners from studios. 

I have lots of powered speakers so I need different legs simply for current. If you don't have to use different legs you are better off because there will always be a different voltage between neutral and ground on separate legs, the voltage difference between neutral and ground is buzz. Yes get the biggest gage cable you can, it doesn't hurt especially that in the future there will be a lot more current usage for powered speakers.

Power is odd it's very simple and at the same time can be a mystery and suck lots of money towards ends that don't make audible differences in the sound of your equipment. 

Some of the comments suggest running 10 or 12-3 and getting two dedicated circuits that would have to share a neutral. This is not ideal and if done wrong I believe can be dangerous. Best research shared neutral if you doing the work yourself. 

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I have three dedicated circuits to my audio area and all three are on breakers next to each other on the same side of the panel. 

Since this wasn't mentioned; this means that 2 of these circuits are probably on one 120 volt leg of a 240 volt service, and the other circuit is another another leg. 

Thinking many of you are not in US, with mention of 220v/240v, I’m located in US … I have been planning, in process of redoing, movie/listening location with a single 20A/120V for three amplifiers (MC303; MC152; Mi254) and two subwoofers (JL F113) … You guys got me all worried thinking that one dedicated 20 amp is not enough. I don’t know how many people notice that most power conditioners, Panamax/McIntosh MPC500 max out at 15A …


Are you all plugging into outlets directly with your components? McIntosh MPC1500 is 20A …

maybe in my case it would be better if I bought two MPC500s used one for regular amplifiers and second one for the two subs? This way, I could justify wiring two different “dedicated” circuits (beyond normal plugs) into the room.

I am pretty sure my electrician used #10 B and W, but #8 green to earth ground in PVC instead of Romex.

mnenasci    Dedicated circuits is a great idea. I have five 30 amp circuits for amps and two circuits for low power, 20 amp. The low power is a 30 amp sub panel fed through a larger Sola isolation transformer.

Upstairs has less than that.


I would run a sub-panel near your equipment with plenty of amps to the sub-panel. If you have high powered amps run them on their own circuits which could be up to 20 amps each. Most likely you can power all your other equipment on one 15 amp circuit.  The amperage draw by your amps will definitely increase based on volume level.  The other equipment will remain fairy consistant regardless. I ran a 100 Amp sub-panel with Two 15 Amp circuits with 12/2 wire and one 15 amp circuit for the tube preamp, streamer, TV and modem/router.  I used to see the voltage slowly drop from 121 to 118-117 when the amps were driven hard.  Now it stays pegged at 121 regardless.  

Ok. I installed my dedicated 20 amp circuit using 10awg romex. All is good!

I will install 3 more dedicated circuits for subs and accessories next. 

As my system has improved, I was forced to recognize that my dedicated 10/3 runs sounded worse than a shared, daisy chained 12/3 run. My advice to all, do it right the first time and buy something like Hidden Treasure or at least get cryo'ed romex from vhaudio, even then I would probably recommend 12/3 if possible. The 10ga sounded better in terms of dynamics and low bass, but the 12ga sounded much better in the mids thru the treble. You could build a couple DIY power cables with 12/3 and 10/3 and listen for yourself before you have the work done. I wish I had.