[djbnh]

I'm having an electrician come over in a couple weeks to run two dedicated 20 amp lines from the box to my audio room. Electrician reported he can run: 1)  two separate lines, one each to a separate duplex (separate hot/neutral/ground for each line); or 2) a different wiring set-up (I'm depending on my memory here!) in which I believe he stated the hots are separate, but the neutral and ground are shared - sorry I cannot remember the name of the wiring for this set-up option.

My inclination is to spend the bit of extra $ for scenario #1. I believe I've read somewhere that it's preferable to keep the analog and digital on separate AC lines; thus, #1 seems to do this.

To complicate things even more, I'm wondering if it would be ok to have the electrician do scenario #2 for my analog gear (thus, four outlets/two duplexes - would have two Odyssey Extreme Mono amps, Odyssey preamp, and my turntable on these lines). I then could have a separate line as in #1 for my digital gear (two outlets/one duplex - I currently only have a cdp, but would leave to expand in the future re: DAC). This would provide for a total of six outlets, four analog and two digital.

Opinions are desired regarding the above. In advance, thanks for your constructive comments.

[Rob S.]

My electrician ran 2 lines (under the crawl space) to my audio closet.  Total bill was $265, with 90 of that in the Romex.  What was your quote?  The only choice I got was whether to have a 4 plug receptacle per line or 2 plug receptacle.  I chose the 2 plug, but had no real "intelligent" reason for choosing it.   I have 2 Mono Extremes on one outlet and the other outlet I have a budget type power conditioner  (VanEvers) which feeds the other stuff ( candela pre, Arcam HT receiver, cdp, sub amp)  In the only other outlet that's not being used I've got the AVA DAC plugged directly into the wall. 

I'm curious to hear more about option #2 for you along with any other suggestions as I'm open to making some changes to my setup.

Rob S.

[MarkM]

I'm having an electrician come over in a couple weeks to run two dedicated 20 amp lines from the box to my audio room. Electrician reported he can run: 1)  two separate lines, one each to a separate duplex (separate hot/neutral/ground for each line); or 2) a different wiring set-up (I'm depending on my memory here!) in which I believe he stated the hots are separate, but the neutral and ground are shared - sorry I cannot remember the name of the wiring for this set-up option.

My inclination is to spend the bit of extra $ for scenario #1. I believe I've read somewhere that it's preferable to keep the analog and digital on separate AC lines; thus, #1 seems to do this.

To complicate things even more, I'm wondering if it would be ok to have the electrician do scenario #2 for my analog gear (thus, four outlets/two duplexes - would have two Odyssey Extreme Mono amps, Odyssey preamp, and my turntable on these lines). I then could have a separate line as in #1 for my digital gear (two outlets/one duplex - I currently only have a cdp, but would leave to expand in the future re: DAC). This would provide for a total of six outlets, four analog and two digital.

Opinions are desired regarding the above. In advance, thanks for your constructive comments.

IMO, It would be best to run two individual home runs to your panel for the audio circuits.   Audio/video circuits that are fed via 3 wire feeds may have very slight interference, works for some. Running two individually fed circuits gives you the ability to change the phasing of the audio circuits at the panel if there is a problem down the road or if you change equipment.


Good luck.

[djbnh]

My electrician ran 2 lines (under the crawl space) to my audio closet.  Total bill was $265, with 90 of that in the Romex.  What was your quote?  The only choice I got was whether to have a 4 plug receptacle per line or 2 plug receptacle.  I chose the 2 plug, but had no real "intelligent" reason for choosing it.   I have 2 Mono Extremes on one outlet and the other outlet I have a budget type power conditioner  (VanEvers) which feeds the other stuff ( candela pre, Arcam HT receiver, cdp, sub amp)  In the only other outlet that's not being used I've got the AVA DAC plugged directly into the wall. 

I'm curious to hear more about option #2 for you along with any other suggestions as I'm open to making some changes to my setup.

Rob S.

Rob, my electrician is a fellow from church, and the area in the basement where he'll run most of the wires before going into the first floor is open, so the total price tag for running two single lines is $160 (he'd charge me $130 for option #2, and $100 for a single line). I know I'm getting a very good deal, and that brings some flexibility in what to do.

Regards,

Dave B.

[JLM]

When I did my room last year (in a new house) I was advised to run one 20 amp circuit per plastic duplex receptacle box and tie them to an independent ground, so we did three.  I splurged and bought cryo'd 20 amp Hubbell hospital grade receptacles for about $30 apiece.  Each monoblock is plugged into it's own receptacle/circuit and the source goes in the third.  As a plus none of interconnects/speaker cables run parallel to the power cords. 

As we live in the country there is no heavy industry, we have our own transformer due to the long underground service to the house, all wiring is 20 amp/12 gauge, and all appliances are new.  So the power is about as clean as possible, no conditioning/etc. used.

You didn't mention the gauge of wire he'd use.  Residential code allows for 12 gauge with 20 amp circuit breakers (the largest used in houses) and that's what I'd do.  (Why do audiophiles buy 10 gauge power cords when their house wiring is typically 15 amp breakers and 14 gauge wiring?)

[Steve Eddy]

The problem with having different components of your system plugged in through two separate dedicated lines is the two long runs of safety grounds all the way back to the service panel. That means more resistance and any chassis leakage currents will result in greater voltage drops and more noise between the components plugged into the two lines.

Ideally everything would be plugged into the same line with the safety grounds tied together through the lowest possible resistance.

Here's a good piece on that issue by Bill Whitlock of Jensen Transformers:

Hum & Buzz in Unbalanced Interconnect Systems

se

[djbnh]

You didn't mention the gauge of wire he'd use.  Residential code allows for 12 gauge with 20 amp circuit breakers (the largest used in houses) and that's what I'd do.  (Why do audiophiles buy 10 gauge power cords when their house wiring is typically 15 amp breakers and 14 gauge wiring?)

JLM, good point - the wiring is 12 gauge. Sorry for the oversight, and thank you for bringing it to my attention.

[DSK]

The problem with having different components of your system plugged in through two separate dedicated lines is the two long runs of safety grounds all the way back to the service panel. That means more resistance and any chassis leakage currents will result in greater voltage drops and more noise between the components plugged into the two lines.

Ideally everything would be plugged into the same line with the safety grounds tied together through the lowest possible resistance.

Here's a good piece on that issue by Bill Whitlock of Jensen Transformers:

Hum & Buzz in Unbalanced Interconnect Systems

se

Good point Steve. I recall reading an article ages ago saying that dividing components across multiple dedicated lines was more likely to increase hum due to different potential. This would seem to suggest installing a higher rated single line (perhaps 30A, 10 gauge) for all components and then implementing isolation/conditioning between wall outlet and components to treat any grunge put back on the line by noisy equipment.

Not being an EE, I wasn't sure whether multiple dedicated lines consisting of the same wire type, gauge, length and age could have different resistance/potential and therefore cause issues? From your comment it seems that it is more a function of the equipment on each line that causes the problems, rather than the lines themselves ...is that right?

[Steve Eddy]

Good point Steve. I recall reading an article ages ago saying that dividing components across multiple dedicated lines was more likely to increase hum due to different potential. This would seem to suggest installing a higher rated single line (perhaps 30A, 10 gauge) for all components and then implementing isolation/conditioning between wall outlet and components to treat any grunge put back on the line by noisy equipment.

Yeah, basically the goal is to have all the safety grounds at the same potential.

Not being an EE, I wasn't sure whether multiple dedicated lines consisting of the same wire type, gauge, length and age could have different resistance/potential and therefore cause issues? From your comment it seems that it is more a function of the equipment on each line that causes the problems, rather than the lines themselves ...is that right?

Ultimately it's the line and the AC cords. That's where most of the leakage current comes from and also the resistance through which the leakage currents flow which cause the noise.

Short of going with batteries, the best would be if equipment were designed to meet Class II standards and then you could just eliminate the safey grounds that cause so much grief in the first place. 

se


[/quote]

[DSK]

So ... in the situation where we run all components off the same dedicated line, and use the same type and length of power cord on all components, but plug the power amp and subwoofer directly into the wall and the source and pre-amp into an isolator/conditioner.... will the 'direct' connected components see a different potential to the 'conditioned' components, thus causing hum?

[Steve Eddy]

So ... in the situation where we run all components off the same dedicated line, and use the same type and length of power cord on all components, but plug the power amp and subwoofer directly into the wall and the source and pre-amp into an isolator/conditioner.... will the 'direct' connected components see a different potential to the 'conditioned' components, thus causing hum?

Well generally speaking the greater the resistance between the safety grounds of the components, the greater the potential for hum and buzz. So in the example you give here, it would stand to reason that the path ghrough the isolator/conditioner over to the safety grounds of the other components plugged directly into the wall would be increased.

se

[jrebman]

Best to check your local electrical codes before spending the money on a separate dedicated ground for your audio gear  it is decided illegal to do this where I live.  One earth ground per house. period.  That doesn't mean it isn't right as far as how well it will perform, but most electricians won't do it.

This could be different depending on where you live, but since I never looked into it anywhere else I've lived, I can't say for sure.

-- Jim

[Steve Eddy]

Best to check your local electrical codes before spending the money on a separate dedicated ground for your audio gear  it is decided illegal to do this where I live.  One earth ground per house. period.

Right. Though I don't think he meant anything along the lines of a separate earth ground. Typically a dedicated line is simply a branch circuit that runs straight from the service panel to the outlet(s) you want to dedicate for audio use. Everything's still tied together at the service panel and there's still only one earth ground.

That doesn't mean it isn't right as far as how well it will perform, but most electricians won't do it.

Actually, a literal earth ground has no relevance at all to an audio system. And it's only used on the AC mains system for lightning protection.

se

[Daygloworange]

Can you elaborate on that a little more? It doesn't have any relevance on audio components?

And please refrain from any expletives. 

cheers

[djbnh]

Ideally everything would be plugged into the same line with the safety grounds tied together through the lowest possible resistance.

Steve, I'm interpreting that what you're recommending I should do is, and I quote my original post: "or 2) a different wiring set-up (I'm depending on my memory here!) in which I believe he stated the hots are separate, but the neutral and ground are shared..." Thus, two duplexes running off the 3/2 wire. Is this in fact what you are stating? In advance, thanks to you and all those who have responded. This is getting interesting.

I clarify that I am not going to have a separate earth ground for the audio gear. All house wiring, including what the electrician will be doing, comes from my home's single service panel. I also add that I'm living in the country - biggest issue with power here is the storms that occasionally interrupt service.

Furthermore, I note I still haven't read anything specifically addressing keeping the digital separate from the analog...

[Steve Eddy]

Can you elaborate on that a little more? It doesn't have any relevance on audio components?

And please refrain from any expletives. 

Sure, I can do that. I'm multi-talented. Instead I'll throw in an epithet or two, how's that?

Actually the problem isn't refraining from any expletives. It's how do you elaborate on that which has no relevance. Kind of reminds me of an old Shel Silverstein poem.

The other day upon the stair
I met a man who wasn't there
He wasn't there again today
Gee I wish he'd go away

Or those who say something like "Show me where it says in the (US) Constitution that Congress can't do that." Well, they can't do it because the Constitution doesn't give them the power to do it, but how do you show them something that's not there?

Ok, let's try this.

The only "ground" that the audio component cares about is its own internal reference ground, which is simply a (ideally) singular point from which other points in the circuit are referenced. So take a cable and connect one end to that reference ground in the component. Now, whether you take the other end of that cable and stick it into the earth, or to the tip of your nose, the circuit's not going to care one whit. It's only referencing that one singular point which will be zero volts regardless of what other point you connect it to outside the circuit.

How's that?

se

[Steve Eddy]

Steve, I'm interpreting that what you're recommending I should do is, and I quote my original post: "or 2) a different wiring set-up (I'm depending on my memory here!) in which I believe he stated the hots are separate, but the neutral and ground are shared..." Thus, two duplexes running off the 3/2 wire. Is this in fact what you are stating? In advance, thanks to you and all those who have responded. This is getting interesting.

You're welcome.

And yes, that's rather what I was saying, in that having the safety ground shared would reduce the resistance between the safety grounds of the two outlets compared to the safety ground of each outlet being run separately all the way back to the service panel, especially if the two outlets are side-by-side and not say on opposite sides of the room.

I clarify that I am not going to have a separate earth ground for the audio gear. All house wiring, including what the electrician will be doing, comes from my home's single service panel.

Ah, good. Didn't think that's what you were planning, but good to know for sure.

I also add that I'm living in the country - biggest issue with power here is the storms that occasionally interrupt service.

Yeah, but those occasions provide golden opportunities for you to get nice and romantic with the wife so she'll continue putting up with all your audiophile nonsense.

Furthermore, I note I still haven't read anything specifically addressing keeping the digital separate from the analog...

That should be accomplished to some degree with the separate hots provided you keep the digital plugged into one and the analogue plugged into the other.

se

[Daygloworange]

Is that what I've heard for years referred to as star grounding ?

What exactly causes groundloops? (I forget that one)

Sure, I can do that. I'm multi-talented. Instead I'll throw in an epithet or two, how's that?

Can you sing and dance too? Ok, I'm envious, I can't do either. Pretty lousy at juggling too....

Cheers

[Steve Eddy]

Is that what I've heard for years referred to as star grounding ?

Sort of , but not quite. Star grounding is a realworld grounding technique which runs the various grounding points of a circuit separately to a single point (which in realworld circuits can have its drawbacks). I'm speaking of what's more generally the concept of a zero volt reference point.

What exactly causes groundloops? (I forget that one)

In my neighborhood, groundloops are usually caused by a combination of teenagers, alcohol, and automobiles.

Did you read that Jensen application note I posted previously? If not, give it a read. It details the classic ground loop.

Can you sing and dance too? Ok, I'm envious, I can't do either. Pretty lousy at juggling too....

I can sing a bit. Can't dance worth a shiii...crap. And can juggle three objects a bit if I practice.

se

[Occam]

Well generally speaking the greater the resistance between the safety grounds of the components, the greater the potential for hum and buzz. So in the example you give here, it would stand to reason that the path ghrough the isolator/conditioner over to the safety grounds of the other components plugged directly into the wall would be increased.

I'm not sure I follow your reasoning. The ground in a power conditioner is generally straight through. Its only additional series resistance are those stemming from whatever additional connections, IEC inlet, outlets, etc....  Ideally that conditioner serves as not only as the power conditioner for those components which we can condition 'line' and 'neutral', but if the manufacturer cannot provide high power conditioning (dynamic constraints), it should provide unconditioned outlets, with all mains grounds linked internally, providing that 'star ground'.
As Steve said, we seek to minimize voltage drops over the ground connections. One can address the 2 components that generate them, the first where we wish to minimize the resistance for those ground connections, so that the leakage currents have minimized voltage drops (we want those ground connections of minimal length, not equal length), and the second is to minimize those leakage currents themselves. That is an issue of component design and layout, and can also be minimized via powerconditioning of the balanced kind. Balanced (technical) power provides an additional benefit above and beyond whatever noise attenuation of the actual power delivery wires, as whatever leakage currents are differential and referenced to ground, they ideally cancel. Personally, I've largely given up on DIY balanced power conditioning, as, for me, I can achieve desired  mains noise attenuation via less bulky and expensive means, and the fact that most of my components are DIY and I can address ground loop issues via Dan Banquer's regime -
http://www.audiocircle.com/index.php?topic=8780.0

Actually, a literal earth ground has no relevance at all to an audio system. And it's only used on the AC mains system for lightning protection.

Insofar as as all our components are all UL class 2, or we galvanically isolate all our signal grounds via signal transformers, this is true. But as soon as a single component has its signal/power ground tied to a grounded chassis (for extremely important safety reasons) we have that original problem of differing ground potentials.
FWIW