Dedicated Power Lines


Been thinking about running dedicated Romex circuits from my circuit breaker box for my rig. No . . . I decline paying for specialty wire, Romex will do. The question is how many discreet lines and the amp capability of each line. I'm still trying to figure out how to do the installation in accordance with Code, without tearing my finished basement apart. For that, I'll consult a licensed electrician.

My rig consists of the following gear: (1) self powered sub that is rated at 1500 "Class D" watts; 4500 watts on a surge; (2) ARC tube CDP; (3) ARC tube line stage; (4) ARC tube power amp rated at 120 wpc - supposedly draws 700-800 watts when driven hard; (5) ARC tube phono pre; and VPI TT. I have a large screen plasma TV and a DVD player. I think that stuff can run off the house circuits.

Right now, everything I just listed is sucking juice off the same line. I gotta believe no good is coming from that set-up. Funny story -- one day my kid was playing Rosetta. I think it's a band that plays music, or at least that what my kid says. Tons of bass. When the band kicked into "low gear," first the basement lights dimmed, then the circuit breaker tripped.

Oh, my house is tied into the utility lines with a 100 amp service. If I change that out, that's the next project. But not right now. Other than Rosetta, no other power delivery problems noted.

Thanks
bifwynne
This is really interesting reading all the posts and suggestions. 1) show me evidence where connecting electronics on the panel as balanced loads split evenly between phases actually causes ground loops and noise. I would bet money that this is an assumption made by people that have no idea what was actually causing their noise and ground loops. 2) Every qualified electrician will ask an important question before installing the new panel box and wiring the "dedicated" lines. That question will be "what will the specific loads be on each phase? And a qualified electrician that is concerned with not violating basic safety and code will pull out a calculator and split the loads equally. I'm not going to argue with anyone here regarding this issue. it is what it is. When I wrote separate lines, I actually meant "dedicated Lines" specifically lines that have three conductors per line. A hot wire, neutral and ground that are not shared with any other circuit and are dedicated lines all the way back to the panel. That is what I meant. I don't care if you use separate conductors or three conductor "Romex" type conductors. It is up to you and your electrician as long as it meets or exceeds code and serves your purpose. Sharing neutrals will absolutely contribute to ground loops and noise. And yes, you have to be very clear to the electrician in the instructions. Tell the electrician that you want "dedicate" lines with a hot, neutral and ground per dedicated line and to not share ground and neutrals. If your system doesn't draw massive current per phase, then it really won't make a difference if you connect it on one phase. However, if you have stupidly massive equipment that is on all the time and draws continuous current, this may overload one phase and is a basic violation of electrical code. Period! I read posts all the time where some well meaning person suggest to someone to do something to "fix" a problem and that "fix" is a violation of some code or safety standard. Such as the continuous use of "cheater Plug" or some other non-sense. But, they wont' be around when someone gets hurt will they? also, if you wire your panel incorrectly and a fire occurs and your insurance company finds out that it was purposely wired incorrectly, this may void your insurance coverage. I'm just saying... Do it correct the first time.
Minorl, I take your point. The biggest energy vampires in my system are the power amp and the sub woofer. The rest of the gear doesn't draw that much current. Let me be clear. If the line stage and phono pre are fed off a true dedicated line from the box off one hot and the amp and sub are fed off true dedicated lines from the box with the other hot of opposite phase, will that set up result in the line stage/phono pre outputs being out of phase with the power amp and sub?
My recommendation comes from years of testing different electrical setups, wiring techniques, components etc., everything you have read here on audiogon I've tried and countless more. The key question here is what actually works, have you actually done these types of testing in the proper manner. An example, breakers and receptacles the main difference between them that makes the biggest difference in sound is the mechanism that secures the wire, then choosing the type of material, plating, etc. they are made of. The good receptacles always give you the option of material but they never offer different mechanisms for securing the wire. Look at a GE breaker, the wire is squeezed tight along the whole circumference of the wire giving maximum surface contact and no air gap, a solid design (one of many reasons I use stranded wire). The main difference between a commercial panel and a homeowner one are the larger copper bars the breakers are secured on, and how they are secured bolted versus pressure fitted. I don't use plastic receptacle boxes simply because after countless times of pulling the power chord out of the receptacle the screws that secure the receptacle to the plastic box simply give out. There are just too many things to go over and do, both large and small that affect the quality of your electrical set-up. There is no electrician that will do what is required simply because they were never taught this. I've worked with a lot of electricians to know that no 2 are alike, I've worked with one electrician for over 10 years now, so he knows what needs to be done. One last thing to consider, what if the people giving the recommendations are wrong, with my set-up you don't have to rip out the walls to make changes.
Every qualified electrician will ask an important question before installing the new panel box and wiring the "dedicated" lines. That question will be "what will the specific loads be on each phase? And a qualified electrician that is concerned with not violating basic safety and code will pull out a calculator and split the loads equally.
05-15-13: Minorl

And for a non audiophile electrician the conversation will go something like this.

Electrician.
"So you want 4 - 20 amp dedicated circuits.
You want me to install #10 gauge Romex wire.
My goodness how much power does your audio equipment draw?
#12 is good for 20 amps per code. Who told you, you needed #10?
So how much power does your audio equipment need?"

Customer.
"Well, my tube CDP I think is around 50 watts. My tube preamp is around 150 watts. My tube phono preamp is around 30 watts. My Power amp is rated at 120 WPC. At full power output of 120 watts it could draw around 700 to 800 watts (800W 6.7 amps full power). My sub I am not sure but class D draws less power than an A/B sub amp."

"I have a large screen plasma TV and a DVD player. I think that stuff can run off the house circuits." (Bifwynne quote)

Electrician.
" So what are you feeding all this stuff off of now?

Customer.
"Just the existing wall outlet."

Electrician.
"You know that is more than likely a 15 amp circuit, fed from a 15 amp breaker."

Customer.
"Funny story -- one day my kid was playing Rosetta. I think it's a band that plays music, or at least that what my kid says. Tons of bass. When the band kicked into "low gear," first the basement lights dimmed, then the circuit breaker tripped." (Bifwynne quote)

Electrician.
"Sounds like the lights are on the same circuit as well."

Electrician.
"Just curious, why do you think you need 4 new 20 amp circuits? I mean I will do what ever you want.... I will say one thing for sure, You will just be wasting your money having me install #10 Romex wire."

Customer.
"Are you sure?"

Electrician.
"OH Ya." #12 is plenty big enough. By code I only need to use #12 wire for a 20 amp circuit. And you really don't have any load to speak of. I mean you are running everything plus the lights off of one circuit now."

Customer.
"Oh I forgot to mention, Can you put the new circuits on the same phase in the electrical panel."

Electrician.
"I will have to check if you have enough empty spaces left in your electrician panel."

Customer
"Somebody told me that an electrician would tell me he couldn't do that." Something about balancing the load across the two hot phases."

Electrician.
"Well technically that is usually the case. But in your case you don't have any load to speak of. You are feeding it all off a 15 amp breaker now."

"I will check your Mains and see if the hot "phases" are somewhat balanced now. The only sure way, to be honest with you, would be for me to put a recording meter on them for a couple of days. Loads are changing constantly."
>>>>>>>>>>>



My rig consists of the following gear: (1) self powered sub that is rated at 1500 "Class D" watts; 4500 watts on a surge; (2) ARC tube CDP; (3) ARC tube line stage; (4) ARC tube power amp rated at 120 wpc - supposedly draws 700-800 watts when driven hard; (5) ARC tube phono pre; and VPI TT. I have a large screen plasma TV and a DVD player. I think that stuff can run off the house circuits.

Right now, everything I just listed is sucking juice off the same line. I gotta believe no good is coming from that set-up. Funny story -- one day my kid was playing Rosetta. I think it's a band that plays music, or at least that what my kid says. Tons of bass. When the band kicked into "low gear," first the basement lights dimmed, then the circuit breaker tripped.
Bifwynne
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05-14-13: Bifwynne
My concern is whether powering my gear with different phase hots could in some way change the output phase of my gear.
As Jim (Jea48) indicated, the answer is no. AC phase has nothing to do with audio signal phase. As you will realize, the audio signal path is powered by DC, which is created from the AC by the power supply of each component.

Regarding the issue of splitting the load between two AC phases, as is usually the case I am in complete agreement with Jim (and Foster_9 and Pbnaudio who expressed similar positions), at least in situations where the AC draw of the system is not unusually large.

I looked through the ExactPower paper Jim referenced, the relevance of which is captured in its subtitle, "A practical guide for AV designers, installers, and electricians."

As an EE with extensive background designing analog and digital circuits (not for audio) I find the paper to be authoritative and credible. Which is to be expected, considering its authors. Among them, Henry Ott (biography here), is a world renowned authority on numerous aspects of electrical and electronic design. Bill Whitlock (biography here) is certainly no slouch either. Some excerpts from their paper:
Less than 300 microamps of ground loop current can cause hum as it flows in an unbalanced audio interconnect cable. However, harmonics of 60Hz that are generated from lighting dimmers or switch-mode power supplies sound like “Buzzz” mixed with a bit of “Hummm” and are more easily coupled by even smaller currents. Harmonics can add together when equipment is powered from different phases, so clearly there is an advantage to specifying same-phase electrical service to power the electronics systems in most cases....

Any leakage currents on the safety ground wires of split single phase load circuits fed by different phase legs will add together due to the 240V potential difference....

Power conditioners do not solve any of these common problems: Cross phase coupling (doubles hums & buzzes) .... What actually does solve them: Same phase power.
Also, regarding ground loops, I would commend this paper by Bill Whitlock to everyone's attention, particularly the first page. It seems to me that if leakage current finding its way to the chassis (and safety ground) of a given component, via stray capacitance in the power transformer, EMI/RFI filters, etc., is out of phase with leakage current in another component that it is interconnected with, inter-chassis current flow between the two components, and therefore susceptibility to ground loop-related hum and noise, will have been maximized.

Regards,
-- Al