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Things to specify to an electrician for dedicated circuits?

A

aim9

New Member
After reading countless threads, and in anticipation of my two MC501s which should be coming soon, I'm pretty much convinced that I should run a few dedicated circuits to the room where my system will be in (at least 3 15A, one for each amp and then the third for the MDA1000/TV/anything else).

I had an electrician come out to give an estimate, and he seemed to be pretty skeptical about ANY sonic benefits of running dedicated circuits for the equipment (keep in mind, the room currently has ONE circuit which also has a bunch of computer equipment plugged into it), which got me to thinking, what exactly does one need to specify with an electrician when running dedicated circuits for audio gear in order to maximize sound quality?

I already ordered some well-reviewed cryo treated hospital grade outlets from A-gon, but beyond that, is whatever the electrician does going to provide the full benefit of running the dedicated circuits, or do I need to specifically ask for certain things to be done? Assume an older electrical panel that's located indoors on a somewhat middle aged home (built in the 70s). I just want to make sure that since I am going to be tearing up the walls a bit that I'm going to get the best possible performance out of the job (without going to extremes of course, he quoted me around $500 for the 3 new dedicated circuits and I'd like to keep it as far under $1,000 as possible). Thanks for the feedback and advice!
 
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Dedicated Circuits

$500 for 3 dedicated circuits isnt outrageous. I ran 1 dedicated circuit myself and the materials cost me about $100 (copper wire isn’t cheap). The only thing I would look into doing differently is looking at an isolated ground setup. I don’t know what advantage that would give your system, but it sounds impressive… doesn’t it?

Also, why are you tearing up the walls? Chances are the electrician can access the top plate of the wall in the attic, drill a hole through the top plate, and then run the wire down to where the outlet box is going to be. There are also outlet boxes that mount to the drywall (instead of the studs) for existing walls so tearing up drywall should not be necessary.

Sonic improvements will be noticeable when you drive your 501s really hard. Amps use a lot of power so you don’t want both of them and your other equipment all on the same circuit because it will really tax the circuit. Have you ever been in a car where someone put a big amp and speakers in the back and every time the bass hit hard, the lights would dim? Same concept here.

Of course I am not an electrician or an expert, so take my post with a grain of salt.
 
Have you had any issues with the computer causing noise? Sometimes computers and audio equipment don't mix. I traced mine to a monitor that did not play well with my stereo.Just something to think about.Good luck.
 
carlthecat said:
Have you ever been in a car where someone put a big amp and speakers in the back and every time the bass hit hard, the lights would dim? Same concept here.

The same thing will happen in a house.I found out when I tried to run 4 Phase Linear 400 amps off the same cicuit.My overhead lights flickered to the music before they tripped the breaker.Can be very heartstopping:tears:
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20A circuits will be some added expense over 15A circuits mainly because of the higher cost of 12ga wire vs. 14ga wire (more copper = more $). The cost difference of receptacles is negligible - oh wait, you have those already. If they're 20A receptacles, I'd have it done with 20A circuits.

Forget about the isolated ground, in typical home construction, there's nothing to isolate from.

Some people also say the dedicated circuits should all be run on the same leg of the mains panel to alleviate any potential issues from having some gear operating on slightly different voltage. It's not uncommon for the voltage on the two legs of the mains panel to be slightly different.

I'm not trying to claim that it will make any difference in the performance of your gear. But, if you believe that cryo'ed receptacles will make a difference, then surely it's logical that something as easily measured as this voltage difference would peak your desire to address the possibility.
 
Rat44 said:
Have you had any issues with the computer causing noise? Sometimes computers and audio equipment don't mix. I traced mine to a monitor that did not play well with my stereo.Just something to think about.Good luck.
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I'm coming off listening exclusively via headphones for a while, and my system isn't fully set up yet, but from what I've heard I don't believe I'm getting any ill effects, but that may be just because I haven't heard any better yet! I assume having the computer stuff on its own circuit is sufficient to eliminate any potential noise coming from it, correct?

whoaru99 said:
20A circuits will be some added expense over 15A circuits mainly because of the higher cost of 12ga wire vs. 14ga wire (more copper = more $). The cost difference of receptacles is negligible - oh wait, you have those already. If they're 20A receptacles, I'd have it done with 20A circuits.

Forget about the isolated ground, in typical home construction, there's nothing to isolate from.

Some people also say the dedicated circuits should all be run on the same leg of the mains panel to alleviate any potential issues from having some gear operating on slightly different voltage. It's not uncommon for the voltage on the two legs of the mains panel to be slightly different.

I'm not trying to claim that it will make any difference in the performance of your gear. But, if you believe that cryo'ed receptacles will make a difference, then surely it's logical that something as easily measured as this voltage difference would peak your desire to address the possibility.
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Yes, the outlets I bought are 15A or 20A, so I could use them with either. I'll ask the electrician about doing 20A instead of 15A. Would it be fine plugging in both MC501s into ONE 20A circuit, that way I'd have a 'spare' 20A for future use assuming I go with 3 circuits?

Regarding the cryo'd receptacles, they're called Porter Ports and if you search audiogon forums they seem to have received a great number of pretty positive reviews, and for $35 each I figured why not. Whether they'll be an improvement over what the electrician would have installed anyway isn't too big of a deal at that price and with the feedback they've received. It's more of a peace of mind thing.

I'll ask the electrician about seeing if it's possible to keep them on the same leg of the panel. I assume the only way to guarantee against any voltage fluctuations is to use some sort of power regenerator? Wouldn't those introduce potential issues with amps (I keep reading that they should be plugged straight into the wall to not rob them of the current they need--but I guess that's another thread)? Thanks for the help!
 
As an electrician I would agree on 20 amp circuits and if you have the money spend it on the next wire gauge up, 10 gauge. For peak draw on amps and equipment the 10 ga. wire gives extra headroom so there is little line loss. The rule of thumb is go up to the next wire gauge after 100' but even if it is not that far to the breaker panel it will guarantee full voltage and less heat loss. 12 ga. wire would be perfectly fine, only do this if you can afford it. Go to Lowes or Home Depot and compare the difference between 12 ga. and 10 ga. wire by the roll. this will give you an idea of what is fair for your contractor to charge. 250' of 12/2 w/ ground in Orlando is $122 for 250'. On Ebay the same roll is $66 plus $12 shipping. On Ebay 10 ga. 250' is $103 plus $40 shipping.
 
Rat44 said:
I believe my problem was RFI shieding.Some CRT monitors are worse than others.
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I actually have a somewhat related story that pretty much puts me in the 'believer' camp in terms of power and the effects things can have on it.

I upgraded our DSL internet to a higher speed a few months ago. It was working perfectly, then in the evening I noticed the speed had dropped down. I assumed it was due to the connection not being stable enough. I power cycled the DSL modem and it worked fine again at the higher speed. Over the next few days, the same thing happened. Then I finally figured it out. I noticed that any time someone in the house got on the treadmill, the internet would basically die for several minutes, then re-connect at the slower speed.

I was about to buy a new treadmill, but thought I might try a power filtering device, so I picked up one of those Belkin PureAV boxes for home theater (only cost around $80 for the lower end unit). I plugged the treadmill into that, and lo and behold, the DSL connection stayed on and at the high speed! I tried it the other way, with the DSL modem plugged into it and the treadmill plugged into the wall, and the problem returned. So the treadmill motor or power supply or something in it was actually sending interference back out through its power cord, which was interfering with the phone lines in the walls. If that doesn't make you a believer in getting good quality power and power filtering, I don't know what will!
 
If I plug my Dish network receiver phone connection into the same jack as my DSL, it's noise will shut off the DSL like a switch. I have to use a wireless phone jack, a misnomer since it actually uses your power wires, to separate the phone DSL modem from the modem in the Dish receiver.
 
20 amp circiuts.
10 gauge wire.
While you're in their I'd add AT LEAST one extra curcuit. Labor cost should be only a bit more.
 
I don't argue against the 10ga wire, but it's so DAMN hard to work with on relatively small things like receptacles. Plus, IMO, it's serious overkill unless the line runs are WAY long. I know these are powerful amps, but it's not like they're a continuous full power load.

Heck, I'd charge extra just for that hassle of working with the 10ga. ;)
 
A true 20amp receptacle should be able to handle the 10 ga. I would think your original choice of three circuits should be more than plenty. I personally would settle for two 20 amp circuits, we're talking amplifiers here, not stoves. I would however spec up to four duplex outlets on each circuit. Codes max you out at six receptacles per circuit, but two each would probably work. In a perfect world you would want to avoid three ways and plugging strips messing up and area that can already be cluttered with wires.
 
I've always used 10/2 with ground copper wire in all the houses I built for rental income. I added 2 service panels to the house I'm in now with 20 breaker slots in each. I have one outlet and 2 light switches per breaker and I can plug in 1500 watt heaters in every outlet I have with no problem. copper is expensive, but my labor was free. A tip on switches and outlets: the screws appear to be backed out as far as they will go when you buy them and that makes a lot of folks think you can't use 10 gauge because it's too hard to cram the wire in that limited space. But, the screws WILL back out more if you force them a little. That will give you enough room to get your loop of 10 gauge wire in just fine. It won't hurt a thing if you unscrew too much and the screw comes out. You can put it right back in. All my outlets and switches are rated for 20 amps because overkill is safer than underkill.

Clay
 
Ditto in the 20 amp circuits and the 10 ga wire.

I'd have him bring a Megger Ground Resistance Tester too (FYI, they ain't cheap, so forget getting one). It will measure your impedance to ground. While code in a lot of places is ~25 Ohms, that allows a lot of crap to stay in your place. I tested at 17 Ohms and had a longer ground rod put in so I was able to hit the water table. My final resistance to ground is 3 Ohms.

Another solution is to dig around your ground rod- about 6" diameter hole and add some Terrafill. This will in effect enhance the contact surface of the ground rod in the soil. This is critical, especially if you live in a dry area.

Terrafill website: http://www.allteccorp.com/prod_terrafill.html
 
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