Practical Power Approaches

http://mysite.verizon.net/vze22yzp/id10.html
(links may not work properly now)

This is what I did, before I found that site. Have a 5 KVA and a 2 KVA that cost about $100 each, not including shipping. They're in a closet with a subpanel. They are fed 240V into the 480V taps. It's sometimes possible to feed them with 120V but, if they complain by getting hot and noisy, STOP that. For safety, I use hospital grade GFCI outlets. I even bought a regulated 1000W Sola MCR portable for $20 but those are noisy. For CDP's or other low power draws, a simple Hammond 500W is plenty, although not balanced. Balanced output derates the output current by half.

There is NEC provision for balanced power but not CSA. Grounding remains intact.

I've got 3 amps, crossovers, etc. and not a hint of noise or ground loop. Got a couple power cords from Ultimate Cables.

Some background with a wee bit of bias from Furman.
http://www.contractorsav.com/article/2006/11/07/ac-power

PS

The benefits of balanced AC depend on the component plugged into it. When I had the SFL2, both myself and a friend almost simultaneously said, "Holy #$@%", within the first few seconds when fed +60/-60. It loved it. Some other components were indifferent and the only benefit was the same as isolation. Apparently, I'm the only one to find components disagreeable to balanced AC but I think that's more of an indictment of the component.

Some have found even the minimal intrusion of an iso transformer to be a detraction. Not sure if they had double the continuous current capacity for their load, which is a good rule of thumb, or any other specific conditions. That's the deal with (any) transformers, they can be unpredictable when not accommodated properly. If you're dealing with 50 Hz, be sure the unit is rated for that.

For power, I prefer EI core as opposed to toroidal. This is 50 or 60 Hz only and the wide bandwidth, close coupling of toroids becomes a disadvantage. There's also DC sensitivity and saturation differences. The advantage of toroids is smaller, lighter packaging, local EMI, and resistance to mechanical hum due to closely packed windings. If it's going to sit in the room AND it's large capacity, toroid might be better under broad conditions.

Efficiency of transformers is usually around 90% but they also draw a minimum unloaded current, dependent on size, so there is a running cost penalty.

Change the outlets that you have at the wall and inside your power conditioner with Maestro outlets from cruzefirstaudio.com These new outlets are one of the most neutral and the most accurate outlets that I have ever heard by far!... and I have tried most of the raved outlets on the market too. I knew outlets made a difference but this outlet makes a BIG difference!...Clearly superior to the others.

Isolation transformers and balanced AC are intiguing, but how can I tell if this approach is the right one to treat the power I get at home? I've been considering alternatives to power "management" (conditioning, regeneration, etc) but always get stuck at the diagnose stage. Trying options is not possible where I live. Addressing power supply does make sense, though.

FWIW, I have 2 dedicated lines, but that's it for now.