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New listening room electrical design

I'm moving to anew house in a few weeks, and trying to figure out the electrical design.
My current room was designed by Rives and I have numerous dedicated lines in it, so, I'm somewhat familiar with the topic.
The new system proposed outline:
New dedicated subpanel, exclusively for the audio components (main located in the garage, adjacent to the new room).
I have 2 speakers (Avantgarde) with powered subs
2 separate JL Fathom subs
2 mono block amps (lamm ML2)
and number of front end component, locate on stand, that going to be on the side wall
(Preamp, crossover, TT and CD player)
I'm thinking:
Two lines with 2 duplex receptacles each to power avant-garde and JL subs
Two lines with one duplex each for Lamm mono blocks
Here is my main question:
For the preamp, crossover, TT and digital I have the following options:
1.   One line with two duplexes for the analog stuff
       Another line for digital
       3 duplex recptacles on 2 separate lines
2. One line (or two) and one power distribution box with 3-4 duplex receptacle, connected to the wall receptacle
3. Two lines hardwired (no wall receptacle and no IEC and power cord in the Power distr. box) to power distribution box, separating analog from digital receptacles inside the box

What is a better approach for the front end components?
Multiple lines feeding one duplex each,
One line feeding multiple duplexes
One line feeding power distribution box?
maril555
erik_squires
15,870 posts
 
I would do the following:

  • Get 2 or three isolated circuits, making sure ground was also isolated all the way to the panel, where they are tied together at the same place.
  • Get Pure Power AC regenerators
The PP Regenerators are active, and will cancel noise on either side of the outlet. That is, they will give you a pure 120 Hz input signal, and will correct for a lot of noise on the other side. They are designed by the same guy who owns Jansen Transformers. Really smart and nice guy.  They are very high efficiency and low impedance.  Parts Connexion sometimes has them on sale.

They do not however have any small units. I wish they had like a 200VA version (at 1/5th the prices) to run my DAC, BD and preamp from for instance.

Point is, they pretty much eliminate a lot of discussions and problems with outlets, wiring, blah blah.

Best,

Erik
jea48
4,313 posts
 

The new system proposed outline:
New dedicated subpanel, exclusively for the audio components (main located in the garage, adjacent to the new room).


JMHO, if the subpanel will be somewhat close to the audio equipment’s branch circuit wall receptacles (15ft or less) imo, that kind of defeats the purpose of multiple dedicated branch circuits for the purpose of decoupling the power supplies of audio equipment from one another. Especially Digital from analog.

Imo, the amount decoupling is largely due the length of the branch circuit wiring impedance of the branch circuit wiring used, especially NM-B cable (Romex is a trade name of NM-B), or MC cable. (Both use THHN insulated copper conductors.)

Of course the other reason for multiple dedicated branch circuits is for fluctuating VD, Voltage Drop, that may be placed on the branch circuit from a big power amp/s playing a high dynamic music source. You don’t want the voltage fluctuating that could/would have an impact on the power amp’s power supply or power supplies of other audio equipment fed from the same branch circuit. Short runs of 20ft or less of #12awg would more than likely not be a problem. When in doubt using #10awg wire eliminates any VD fluctuations problems as the power supply of an amp draws quick gulps of current to recharge the caps in the power supply.

As always YMMV.


maril555 OP
619 posts
 
Thank you jea48,
Great info, as always.
However, not being an electrician, I'm having a hard time to picture having one or two lines with 6-8 outlets located in different locations?
I'm sure any electrician would know how to do it, I'm just trying to understand that for myself.
And, BTW, the subpanel in my case will be literally behind the front wall of the listening room, in the adjacent garage.
That's is the wall, where the outlets for the mono blocks are going to be.
The other two outlets will likely be on the side walls for the JL subs and powered subs in the Avantgarde speakers
And yet, another group of outlets for the front end components will be further away from the front wall.
And I would definitely go with at least 10/2 Romex.
I was actually thinking of 8/2 just for the amps.
Since we are on this topic, what specific brand and model of the subpanel would you recommend?
jea48
4,313 posts
 

However, not being an electrician, I’m having a hard time to picture having one or two lines with 6-8 outlets located in different locations?


First, my intent of my previous post was not to discourage you from installing multiple dedicated circuits.

As for feeding more than one receptacle outlet from the same branch circuit it is done all the time. The feed in and feed out wires in the outlet box are jointed together and pigtailed out for connection of the duplex receptacle. As for the wire connector used to make up the joints, connections, a spring type connector should be used. Example, Scotchlok brand made by 3M or equal as used in commercial/industrial facilities. Stab in connectors used in residential dwelling units are junk!, imo.

https://www.egr.msu.edu/eceshop/Parts_Inventory/datasheets/insulated%20electrical%20spring%20wire%20...

//

I was actually thinking of 8/2 just for the amps.


#8awg? Must be some really big powerful amps. #10 is more than big enough. VD will not be a problem for your short branch circuit runs. I would be willing to bet the plug on the power cord feeding the amps is only a 15 amp plug.

//

Since we are on this topic, what specific brand and model of the subpanel would you recommend?


First, copper bus only. Stay away from a panel with Aluminum bus. The problem isn’t that the bus is aluminum it has more to do with the bus breaker tie connection made to the branch circuit breaker bus tie connector connection.

I personally like the Square D QO series. It has copper bus. Stay away from the Square D Homeline series. It has aluminum bus and I don’t care for the branch circuit breakers.

How big of a feeder was you thinking about to feed the sub panel?

For house resale I would wire the panel 120/240V. Though you will/should still have all your audio equipment that is connected together by wire ICs all fed from the same Line, Leg. All from Line 1 or all from Line 2. Not from both.

//

You need to find a good licensed electrical contractor/electrician to work with you. He will know what is required for local electrical code in your area.

Worth noting if an electrical permit is pulled there is a very good chance the branch circuit breakers in the new sub panel will have to be AFCI (ARC Fault Circuit Interrupter) type. Maximum breaker size for a 20 amp branch circuit is 20 amp, no matter if the wire is #10awg.

The electrician more than likely will have to install tamper resistant duplex receptacles for the final electrical inspection and then change them out to your audio grade duplex receptacles, after the electrical inspector signs off on the job. Ask him up front if local code for your city requires them. If yes then ask him if he will change them out after the final inspection. He may say no. He may not have any problem with changing them out providing you say you did it and not him.

Beats me why the manufactures of the audio grade receptacles are not making them tamper resistant for a residential dwelling unit application.

maril555 OP
619 posts
 
Jea48,
thank you again
Great info.
one more question- how would you suggest to install 2, or 3 duplexes on the same line in the same location?
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