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More questions about dedicated lines

We are moving to a new house built in 2007  and I am fortunate enough to be able to move a wall to create a room with golden ratios. I will need to run some new electric and it gives me the opportunity to run dedicated lines.  I have spent countless hours rummaging through the 7k discussions on this topic and have a decent idea of what is needed.  My plans are to have four runs of Romex 10/2, one each for each monoblock VAC signature 200's, my digital, and my Audiokinesis swarm which has not be set up yet.  I estimate the runs to be conservatively 45 feet including up and down distances. All runs will be of equal length ending in SR  outlets. They will be separate from each other and all other lines and no metal staples will be used.  When I told him I my goal was to have the best sound he offered a suggestion that I hadn't come across in my electrical education here on the gon.  He suggested placing what sounded like a commercial power regenerator with a large battery bank as the first step out of the breaker box and running lines from this.  The other options were to run from a preexisting sub panel that has the pool pump and a few lights on it, but nothing else.  Third is straight out the breaker box.  He wanted to put the runs closest to the utility line in, stating that there will be less noise upstream than downstream, but this puts these lines next to a big double breaker (cant' remember what it is but is sure to be noisey).  He understands that I want all lines on the same phase, or line,leg.  My questions are: Of the three options, which would be best?  Is there anything else needed to minimize the risk of ground loop hum if I use separate hot, return, and gound for each line and not share ground neutrals and keep all lines separated from themselves and other lines.  If going through a subpanel with little on it, how do I manage to keep all runs on the same phase without unbalancing the breaker? A third tangential question-Is it best to use metal or plastic housing boxes for the receptacle? The question of durability of the plastic fatiguing and breaking following repeated plugging and unplugging has been mentioned but I didn't see an answer.  Finally, a huge thank you to jea and almarg for their voluminous responses in all the prior electrical discussions-I got an education.  Sadly, I still don't speak electricalese.
orthomead

Showing 2 responses by almarg

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almarg
9,670 posts
 
Thanks, Mike (Mijostyn).

@the_treble_with_tribbles, before a battery bank/inverter approach would be chosen I would want to see considerable additional technical detail on the specific make and model the electrician recommends.  The concern, IMO, being the possibility that the inverter circuitry in whatever unit it is, which may or may not have been designed with audiophile applications in mind, might generate RFI that could couple into the audio system.  Or for that matter, given my limited knowledge of such devices, could conceivably even generate a stepped approximation of a sine wave, rather than a true sine wave having good distortion characteristics.

Regards,
-- Al
 
almarg's avatar
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almarg
9,670 posts
 

Orthomead and Bob, thank you kindly for the nice words. And kudos, Orthomead, for having done such thorough research.

Regarding the power conditioner Bob referred to, which is no longer made but was formerly produced by Elgar, see Atmasphere’s post dated 10-7-2016 in the following thread:

https://forum.audiogon.com/discussions/power-conditioner-help-3?page=2

… as well as the two posts dated 5-20-2016 by Dragon_Vibe in this thread:

https://forum.audiogon.com/discussions/what-does-a-power-conditioner-really-do.

However given the weight, expense, probable need for refurbishment, and marginal availability of this unit I suspect you won’t want to pursue this approach.

Regarding keeping the two AC legs from becoming significantly unbalanced, I would infer from the literature on your VAC amps that they operate primarily in class AB, since only the input and driver stages are described as operating in class A. And given their 200 watt rating in mono mode I suspect that aside from occasional very brief dynamic peaks in the music each amp will probably be supplying well under 100 watts to the speakers, with the two amps together consequently drawing no more than about 500 watts of AC. With the system as a whole probably drawing no more than 800 watts or so most of the time, including the sub amp. Which seems to me to be sufficiently low that keeping the legs in balance is a non-issue, regardless of which of the three approaches is chosen.

Regarding ground loop susceptibility, while connecting different parts of a system to separate dedicated lines can be advantageous by minimizing coupling of noise among the various components, it can also sometimes increase susceptibility to ground loop issues. So there is a tradeoff involved, which generally has little if any predictability. But with the four dedicated lines you’ll have a lot of flexibility in terms of what gets plugged in where, and if a ground loop issue were to arise with the connection arrangement you’ve described you’ll have other alternatives available which should eliminate it.

I have no suggestions to offer as to the choice of metal or plastic for the outlet housings. Perhaps Jim will chime in on that.

Finally, regarding the three approaches you’ve asked about:

Regarding the possibility of using the large commercial regenerator that was suggested by the electrician, if I understand correctly this sounds as if it may be something like a very powerful UPS (uninterruptable power supply). If so, what I would ask about is the possibility that the circuitry in it might generate significant RFI (radio frequency interference). I can tell you that if I bring a portable battery powered radio within a foot or so of the relatively small UPSs I use for my computer systems (which are the type that generates true sine waves, not stepped approximations of sine waves as is done by many inexpensive UPS devices that are presumably more noisy) the high frequency noise radiated by their circuitry is picked up very strongly in the AM band.

Regarding a choice between the other two options, it’s possible that option two as well as option three would be good choices if the pool pump and the audio system would rarely be in use at the same time, and if the wiring between the main panel and the sub-panel is of sufficient gauge. But with the heavy gauge you’ll be using for the dedicated lines and the reasonable lengths that are involved voltage drops in the dedicated lines figure to be insignificant with either approach, while the increased inductance of the greater length that I assume would be needed for option three may provide a bit more filtering of high frequency noise. So my instinct would be to agree with Bob, that the third option is probably a better bet than the second.

Good luck. Regards,

--Al


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