I have two dedicated 20 amp lines in my listening room configured in precisely the same way that you are planning to install yours and my system is absolutely dead silent. Moreover, I have four additional dedicated 20 amp lines in other rooms throughout the rest of the house for two large-screen TVs and accessories.
Dedicated 20 amp/ground loop question
Hi all.....I am getting ready to start construction on a new home and I am trying to get all the plans ready for the electrician for a dedicated 2 channel music/library. I am planning on having the speakers on the end of the room (18 X 23) and a McIntosh MC352 amplifier placed in between the speakers on a stand. I would like the rest of the equipment on one of the side walls so I can run 1 set of balanced ICs to the front and that's it.
I am planning on having the electrician do the dedicated circuit(s) to this room....I've read on here about the existence of ground loops if you run 2 or more dedicated lines. I was plannning on having one dedicated line to the digital/preamp/etc. on the side wall, and one dedicated line to the McIntosh amplifier. Does anyone know if this arrangement would have a good chance of producing a ground loop since the receptacles will be separated from each other in the room?
I am planning on having the electrician do the dedicated circuit(s) to this room....I've read on here about the existence of ground loops if you run 2 or more dedicated lines. I was plannning on having one dedicated line to the digital/preamp/etc. on the side wall, and one dedicated line to the McIntosh amplifier. Does anyone know if this arrangement would have a good chance of producing a ground loop since the receptacles will be separated from each other in the room?
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You should be just fine but here are some additional tips: > Run 2 dedicated lines to the side location. One for anything digital (meaning anything with a DAC in it ;-) and the other line for everythng else. > Run 2 dedicated lines to the amplifier end of the room: one behind/beside each speaker location; and then extend one of those lines to another receptacle midpoint on the back wall. Why? It will only cost another $200+ to do it now, and it will allow you the flexibility of going to monoblock amps and/or powered speakers (like MartinLogans) in the future. > Make sure you tell your electrician you want all dedicated circuits on the same phase (i.e. all the dedicated circuits' breakers on the same side of the neutral buss at the panel.) > Size everything (breakers, wire, and receptacles) for 20A service. Also, since this is new construction, you might want to ask your electrician to provide a couple of (minimum 2" diameter) empty conduits (plastic with no sharp bends) going from the floor (or wall) behind your preamp and coming up out of the floor behind each speaker location. These are for your long interconnects from preamp to amp(s). (Make sure he leaves pull cords inside them ;-) . |
Thanks you all, I appreciate all the responses......got the conduit covered etc......one last thing....should I assume the electrician should know how to do this type of install (it's about a $600,000 custom home), or does quality not matter when it comes to this, therefore do you think i'll have to spell all this out for him? |
The ground loop concern you are referring to, to the extent that it is a concern, is only applicable where the components that are on different dedicated ac lines have single-ended interconnects between them. It is no concern at all with the balanced runs you'll be using. The reason for that is that the shields of single-ended rca interconnects, which serve as the return path for signal currents, also connect the two chassis together, which are in turn connected to ac safety ground. So any voltage differential between the ac safety grounds of the two sets of outlets will cause an extraneous current to flow in the interconnect shields, in common with the signal current. If any of the other components you will be connecting to separate dedicated ac runs will be interconnected single-ended, such as if you have digital sources and your preamp on separate dedicated ac runs, you can do two things to minimize the likelihood of ground loop problems. Keep the interconnect length as short as possible, and use a quality cable that presumably has low shield resistance. Best of luck with the new house. -- Al |
Excellent advice from NSGarch. Especially: "Make sure you tell your electrician you want all dedicated circuits on the same phase (i.e. all the dedicated circuits' breakers on the same side of the neutral buss at the panel.)" In addition to this, have the electrician arrange the breaker box such that all 'dirty' appliances (microwaves, garage door openers, home PC/server/router, refrigerator, and anything with a switching power supply) are on the other side of the neutral buss from where your dedicated lines are. Another even better idea is to run a separate service/breaker box directly to the closet of your soundroom and wire all of your outlets in that room from it with some of the higher grade/cryo'd wire instead of standard Romex. Good luck. |
And if you have really deep pockets, use one of these (for the separate breaker box that Dlcockrum suggested ;-) http://www.aaudioimports.com/ShowProduct.asp?hProduct=64 |
