Same leg/phase. At the top, on the side with the least number of noisy appliances.
7 responses Add your response
Agreed...just put two in my room in late July. I had the electrician wire them so that;
- they were on the same leg/phase
- they did not share a neutral
- all circuits were re-ordered s.t. the 20-amp dedicateds were the 1st 2 circuits off the main; this helps in that when A/C, heat pump, water heater, washer/dryer, etc...come on, they are downstream from the system i.e., the system gets first call on all power coming into the house
- the two new 20-amp lines were multi-stranded oxygen-free copper; don't use Romex (sp?)!
Hope this helps!
Use different phases for each of the monoblock circuits and maintain the same length of feeder. If you keep all your equipment on the same leg you'll be inviting a ground loop hum, especially with four circuts.
Factors which induce ground loops: monoblocks on same phase, different length branch circuit feeders, multiple dedicated outlets with only one component plugged in and all connected with RCA I/C's, unbalanced main panel, poor contact to main ground and proximity to power cords or feeders behind walls and floors. This is simplistic, as there's a lot more to it than just the "same phase - no! - different phase" argument.
I just put 4 new dedicated line's going to my system.A line for each component.I have mono blocks, a pre-amp & a cd player.Should they be all on the same leg/phase from my service box or should there be a change??First, there is only one phase. The secondary of the utility transformer feeding your home is only single phase. The secondary of the transformer is centered tapped, (split phase). At your electrical panel you have 2 hot conductors, (L1 & L2), and one grounded conductor the (neutral). The center tap of the transformer is the neutral.
99.9% of audiophiles will tell you to feed all your audio equipment, that is connected together by ics, from the same (Line) to neutral of the electrical panel. Try it both ways and post back your results......
Just a note, I take it at the present time both Amps are plugged into the same receptacle, same branch circuit, same Line..... Any ground loop hum?
I will also add I have read many post over on AA where after installing dedicated lines to feed mono amps a ground loop hum was created. The hum did not change whether both amps were fed from the same line or one was fed from L1 and the other from L2......
I think the the ground loop hum issue has more to do with the length of the branch circuit wire... Long runs seem to invite ground loop hum problems. How long will your runs be?
Again, it's more involved than just which leg of the panel you place the breakers on. With single phase power, each leg provides 120 volts referenced to ground. There are two of these legs and the start of getting good power to your gear is to keep each leg at the same voltage to balance the entire house power. The idea is for each leg to provide the exact same current to all the loads which results in a perfect zero current on the neutral. If one leg has more draw than the other, the net result will be current in the neutral. This is the start of power problems IMO - ground loops, RFI/EMI noise, arcing noise (popping sounds thru the speakers when a light switch is turned on/off, etc.) and common mode noise being amplified.
Monoblock amps each draw the same current, but a lot more than the source components so they will tend to unbalance and place a current on the neutral if on the same leg. If they are on seperate legs the total power draw is balanced vis-a-vis the neutral but might not have the same potential across the amps, which can cause ground loop hum. I think balanced will yield better results.
If you only have one amplifier then I would opt to put all components on the same leg. This is because all the components will have the same potential across them with respect to ground and there is, in theory, no chance for ground loop hum.
But that's an ideal - you have to factor in all the power drawn in the house and see if the loads are fairly balanced. If they are not, then it matters not how the circuits are wired; any benefits will be countered by noise, etc. Not only that, but things like computers, fluorescent lighting, power supplies, battery chargers, digital clocks add noise to the power by introducing spurious current from harmonics of the 60 hz frequency. Dedicated circuits, while helpful, will not clean the power to your equipment.
In my new house, I have rewired my as-yet-to-be-renovated listening room and house panel to such an extent that I can use line voltage dimmer switches in my listening room with no ill effects. I had to go through the trouble of figuring which loads are simultaneous, which loads draw what current, which are resistive or inductive and wire accordingly. My system, all RCA interconnects and no cheater plugs, is dead quiet - even with your ear to the speaker. I use one dedicated circuit for each of my monoblock amps plugged directly into the wall and one dedicated circuit for the front end plugged into a Z-Stabilizer. Each amp circuit is on a different leg and the third circuit was placed on the leg that balanced with the rest of the house.
Dedictated circuits and which leg they're on is a start. But IMO, there's more to it. I didn't mean to confuse you, but only to give both sides and relate to what I did (that works for me) so you can see if your case is similar. Sorry, a feeder is what you call a length of BX or romex that you run from outlet to breaker.
Gs: I did not have a chance to thank you for your post back in November as I learned alot from it. In speaking with my contractor who did my additional wiring it seems that when I made my original request to skip the Romex and move the circuits to the 'front' of the panel, etc...he did the following back in late July;
- agreed that Romex should be avoided at all costs for any audio or video circuit that one cares about
- rebalanced the whole house (see '*' below) and moved all circuit in panel accordingly
- followed my instruction/payment to get hold of the best commercial multi-strand OFC
- ran each 20-amp circuit within PVC under the house and separated them by a little over a foot
- (*)measured potential and draw on all circuits in the house with heat pump, refrigerator, washer, dryer, lights, etc....all running and then in various combinations
- took the calculations of current draw, etc...I'd obtained from the manufacturers of my gear to add to the mix
My circuits are dead quiet (preamp on 99db) and perhaps the fact I'm not using monos (vertical bi-amp with Edge NL12.1's) and the fact that I used balanced cabling throughout my 2-channel setup is working well together.
Thanks again for the post; when I discussed this with him yesterday he agreed wholeheartedly and showed me the main house panel explaining all the changes he'd made along the way.