Dedicated Line?

kolyan2k

Early B. wrote: »

This is the closest thing I've found to what I'm looking for (I think), but it's still too costly: http://www.partsexpress.com/pe/pshowdetl.cfm?Partnumber=100-790&raid=53&rak=100-790

About $400 for my application. May have to settle for Home Depot's Carol...

However, I paid a similar price for my speaker cables and they're only 10 ft. Hmmmm.

Will it work? Is it worth it? I dunno...

they are running only 3 wires. 12/3 is a 4-wire cable (white, black, red, and ground) i suppose you can cut the shield and use it as ground

p.s. i did a little more research on speaker and power cables:

theoretically, a shield in a Power cable can make a difference if your audio cables are not shielded or poorly shielded, since it can keep the noise inside, just like audio cables are made to keep the noise outside. (gauge (14 or 12) and wire type still does not matter). speaker cables do not have to be shield in most cases due to the type of signal they carry. so the only place where you need to pay attention to the wires you use is connecting components together. and there is no better connection then XLR in this case.

bikerboy

Hi Early,
I have 2-12 ga lines to my 2 ch system and think a third would help. One line for amps, one for analog, and one for digital if I could do it again. Maybe your monster ps conditioner will help. So whatever you choose to do, add an extra line because the wire is the lowest cost of the whole thing. If you have monoblocks each amp could have a line. As you can see electricians cant agree so do it to code but have more than enough lines so in the future you dont wish for more because you know you will. Just my 2 cents. Thanks.

sickicw

Early B. wrote: »

Uh-huh.

If you tell any audiophile out there that Home Depot speaker cables are the best you can get, he will laugh...

See the problem here?

I used a mix of 10 gauge audiophile cables, and 14 gauge home depot cable (for my rears) and they both sound pretty good. anyway, i have 4, 20 amps circuits. The run was about 70 feet or so all through the attic and into my walls. just cut out a small hole at the bottom for the box. it cost me about $600. Probably a little pricey, but i told the guy i needed it done ASAP, so im sure he charged me a little more..

Early B.

ben62670 wrote: »

I was an electrician for a number of years. Have a pro do it. With a basement it shouldn't be more than $250 total. It is almost all labor. What I would do if I were you is have them run 12/3 wire. It will share the same ground, and neutral. You will end up with 2 20amp circuits for your AV, and only adds $40 or so to the total cost. I like to plug my amps directly into the wall, and you could easily have them install a 4 gang box which would give you 4 plugs per circuit 8 total.

OK, let me make sure I understand -- I want to set up two duplex receptacles (total of 4 outlets) for my 2-channel system. If I use 12/3 wire, does that mean that two 20 amp breakers are fed off a single wire, or would I need to buy enough 12/3 wire for two separate runs for each duplex?

I'm asking so I can be more informed. I'm not gonna attempt to do this myself.

Thanks.

SCompRacer

What was suggested is common in standard electrical distribution systems. Two of the wires in the 12/3 would connect to individual breakers and each of your duplex outlets, the neutral and ground wire would be shared by both circuits. A qualified electrician would know in order to do this; the breakers must be on different supply bus in the service panel (one on each of the incoming power feeds). That is, breakers under one another, never across (on the same bus). Both breakers on the same bus will cause excess load on the shared neutral and it could fry.

For audio use, I would go with electronics grade power distribution. That is each outlet have its own neutral and ground (a home run in electrical speak). Benefits of separate neutrals and grounds are reduction of common mode voltage (between neutral and ground) and reduction or elimination of common mode noise (neutral to ground voltages). The cost will be greater of course, but why get cheap when it comes to powering the gear.

SKsolutions

I would think that the biggest improvement would come from having nothing share the circuit, rather than what gauge the wire is. Any resultant increase in resistance from using 12 rather than 10 gauge in a run less than 150ft, would be very minor For a short or easy run, I'd use (2) separate 12/2 homeruns (panel to box). For a difficult run (through finished or tight areas), I'd use the 12/3 (one wire with 2 circuits). For a very long run, I'd have fun pulling the 10 gauge.

Most SS amps have bigass Caps in them, and I doubt they ever get close to 'E' because your not getting enough power. You just don't want fluctuations from other components on the same circuit getting amplified.

Early B.

After doing some more research, I decided to go with 12/3 and two circuits mainly for this reason (copied from AudioCircle Forum):

"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."

Besides, I suppose this option is a bit less expensive and should be easier to install.

I plan to purchase the materials myself, then have someone do the install. I'd rather pay for labor only, not additional upcharges for picking up the materials. I use the same technique for auto repairs and it saves me a lot of money. So here's a list of what I think I'll need:

- 60 - 70 ft. of Romex 12/3 (I'll probably buy a 100 ft. roll; the breaker panel is about 50 ft. from the install location on the same level)
- two 20A breakers
- two 20A hospital grade AC receptacles & plate
- one 2-gang box (old work?)

I don't know a damn thing about electricity, so any comments or corrections are appreciated.


BTW -- this is for my 2-channel system. Right now I only need two plugs for my CDP and amp; I use a passive pre. I haven't decided if I'll use the dedicated line with my HT system, although both systems are in the same location.

reeltrouble1

I have two seperate lines into the Shed. A thirty amp for the amp and a 15 for the rack.

It works great.

The End.

RT1

SKsolutions

Early B. wrote: »

After doing some more research, I decided to go with 12/3 and two circuits mainly for this reason (copied from AudioCircle Forum):

"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."

I'd verify that Early. In a 70' run with good equipment, these are non-issues. A voltage drop for chassis leakage? Crazy.

Running two direct home-runs and grounding in the box is best if you can snake the 2 wires. There will be no issues with a common neutral, and the grounds don't touch till they are tied into the panel.
Look at the super high end installations with their own 150A service and ground. Everything is run direct. . no common neutral. I would only do the 12/3 on my own install if it was really difficult to snake the 2 separate wires.

read-alot

I too would run 2 separate 12-2 with ground circuits.

Something about using one netural for two separate runs caused my brother who has been a master electrician for 22 years to short wire when I asked him about it tonight.

wz2p7j

Running 12/3 and plugging into opposite phases of 240V service gives you something called a 240V circuit. Anyonw using 240V amps or pre/pros's?

Chris

Early B.

read-alot wrote: »

I too would run 2 separate 12-2 with ground circuits.

Something about using one netural for two separate runs caused my brother who has been a master electrician for 22 years to short wire when I asked him about it tonight.

I dunno. Even if I thought I knew, I still wouldn't know.

As this thread clearly indicates, you get different answers from the professional electrician crowd versus the hard-core audiophiles. Hell, these two groups can't even agree on the appropriate wire gauge. I'd prefer to use 10 ga., but the electricians say it's too hard to work with and it won't make a difference, so I settled on 12 ga.

I also don't know if the wire will be difficult to snake or not, so I'd rather err or the side of making it easier with a single wire run. This option will also make it a tad bit easier on my wallet.

Finally, I don't know if there will be any sonic differences between the two home runs option and the single wire option. But either option ought to be much better than what I have now -- several outlets, a light dimmer, and ceiling fan on the same circuit as my AV system.:(

treitz3

Early B. wrote:

As this thread clearly indicates, you get different answers from the professional electrician crowd versus the hard-core audiophiles.

There's a surprise :rolleyes: . I'm both and it's hard, I just go with what my ears tell me. That's what matters most.

Systems

Early B. wrote: »

I'd prefer to use 10 ga., but the electricians say it's too hard to work with and it won't make a difference, so I settled on 12 ga.

(

I had to make the same decision when I ran my dedicated line.I chose the 12 ga over the 10 ga for two reasons namely cost and it is rated to carry 20 amps so is plenty sufficient to feed my power amps.

Early B.

GV#27 wrote: »

I had to make the same decision when I ran my dedicated line.I chose the 12 ga over the 10 ga for two reasons namely cost and it is rated to carry 20 amps so is plenty sufficient to feed my power amps.

Thanks for letting me know. Based on how you've helped me in the past with technical issues, I value your opinion.

Systems

Early B. wrote: »

Thanks for letting me know.

Your welcome.

dragon1952

While we're on the subject, is there any advantage/disadvantage to using 12/2 on a dedicated 15A circuit for a lower powered 2-channel system?

reeltrouble1

Early,

One caveat as you do like to change out your gear from time to time!!!!!

As I was researching this for my system I found several amp makers who are now recommending the 30 amp lines, in my case BAT, although I installed my own line along with some 20 amp lines as well I really did not find the wire much different or harder to work with, lets remember, general electricians no little of our world or what it may take to operate a ballsy amp. Sure the vast majority of amps can use the 20 amp line, however, I certainly am happier with my 30 amp line with my particular amplifier.

RT1

Systems

dragon1952 wrote: »

While we're on the subject, is there any advantage/disadvantage to using 12/2 on a dedicated 15A circuit for a lower powered 2-channel system?

No disadvantages other than what it will cost to install.As far as performance gains with a low powered amp I dont know, but it is nice to have in case you upgrade to bigger amp in the future. Then you can use the dedicated line for the amplifier and run the source components off an other circuit.

Early B.

reeltrouble1 wrote: »

Early,

One caveat as you do like to change out your gear from time to time!!!!!

Who? Me?

No, no. That guy is the late Early B.

SKsolutions

dragon1952 wrote: »

While we're on the subject, is there any advantage/disadvantage to using 12/2 on a dedicated 15A circuit for a lower powered 2-channel system?

Unless your maxing out your service, you could replace the 15A breaker with a 20A because you have the 12 gauge wire. If you had the 14, you could not.

dragon1952

This is new construction. We'll have 2 families, my Mom and Dad on one floor and my wife and I on the second floor, so due to having to have 2 kitchens, laundry rooms, plus a hot tub, etc. we had to have 2 power panels so there is plenty of room. I told the electrician I'd like to share a dedicated circuit for the music room and HT and that I'd prefer 12 gauge but that I didn't think I really needed a 20A breaker. The HT is in a separate room and I won't be using both at the same time. I've only got a 50W tube amp and a CD player for the music room. This does give me the option of using a 20A breaker in the future and in the mean time I figure the use of 12 gauge can't hurt. Sorry Early, don't mean to hijack just want a quick answer.

Systems

No need for a 20amp breaker unless you have constant nusance tripping.I have a 15 amp breaker on my 12ga dedicated line and it supplies 3 Bryston amplifiers and it has yet to trip once.

SKsolutions

Lesser amps with smaller filter Cap values may actually require more current on demand than a Bryston would, but I agree about the 15A being more than enough especially with Tubes. ^^^^
The larger gauge run is what is important to not have to upgrade later. . a breaker is a 2 minute swap.

After dedicated lines, if I was building new, I'd have a separate ground installed just for the electronics. Short money.

I would be very interested in reading of the improvement that Early hears, and the cost/benefit ratio in comparison with other wire/IC upgrades.

reeltrouble1

Back when I had my amp on a 15 amp line and plugged a light into the other plug in the outlet I could make the light dim as I turned up the gain on the rig, a voltage drop would occur causing this dimming along with blowing the fuses protecting the amp pcb. The acutal breaker in the box never tripped even a slow leaner like me can figure this cannot be a good thing.

Another member here plugged a circular saw into the same 15 amp line as his tubed amp line and yep, the tubes made a total commitment with the dance of fire.........

My EE son-in-law (pea brain) explained all this to me in EE geek talk, but who really cares.

Empirical Data can be a "reel" learning experience.

RT1

unc2701

GV#27 wrote: »

No need for a 20amp breaker unless you have constant nusance tripping.I have a 15 amp breaker on my 12ga dedicated line and it supplies 3 Bryston amplifiers and it has yet to trip once.

Weird- my 4b plus the two sub amps on the LSi25's popped the 15a line everytime. Now I've got a 20a each for the 4b & Gallo SA, plus a 15a for everything else.

Systems

unc2701 wrote: »

Weird- my 4b plus the two sub amps on the LSi25's popped the 15a line everytime. Now I've got a 20a each for the 4b & Gallo SA, plus a 15a for everything else.

Yes zero trips of the breaker,and actually its four as I forgot the mono PP120 .The others are a 3B and two 2B LP's and they are the only components run from the dedicated line.Being lower powered units that don't have huge current demands they don't draw enough to trip the breaker.If I was using multiple 4B's then I might have to throw in a 20 amper.

MikeC78

Why not be on the safe side and make it a 20amp breaker? Since you already have the 12g wire seems like a no-brainer to me? Don't have the service?

Systems

MikeC78 wrote: »

Why not be on the safe side and make it a 20amp breaker? Since you already have the 12g wire seems like a no-brainer to me? Don't have the service?

It,s a matter of not needing it,if it does not trip the 15 then I have nothing to gain by changing it to a 20. Also the 15 amp provides better fault protection.

MikeC78

Better fault protection, how do you figure? There's a LOT of things we DO NOT need in this hobby, but I believe skimping on your power isn't one of them.