Used both balanced and isolation with general purpose step-downs and various others.
http://mysite.verizon.net/vze22yzp/id10.html
For amps in general, never found much benefit for balanced AC. In fact, my Plinius amps are completely indifferent, other than needing a stethoscope to detect any noise, but I still keep them on a 60/60 diet because it doesn't do any harm. My Genesis 1600W bass amp is the only piece plugged direct to "the wall". For class A/B or D amps, even with 10X capacity, a transformer can still be a "speed bump" because those amps recharge capacitors in less than a cycle. Class A amps, with a steady amp draw, are a good load for isolation transformers.
On the other hand, preamps and sources have responded well to balanced AC. In some cases, like the SFL2, which has a power supply larger than many amps, the difference was shocking (sorry, bad pun).
Agree with Zman that multiple smaller isolation transformers are better than one. That is the point of isolation. Do you realize the weight of a 15KVA transformer?
Code issues with distributed (through wall) balanced AC that Equi=Tech has dealt with but that doesn't apply to boxes in room or on the rack.
There's also the running cost. Although they're quite efficient under load, they have an "idle" or exciting current (typically 10% of capacity). Although larger transformers have a lower percentage of exciting current, it's always more.
Gotta disagree with Jeff about the Sola CVS (and MCR) regulated transformers. They are great for their intended purpose but they're noisy and don't respond well to dynamic loads. The CVS series provides less isolation and noise reduction.
Prefer standard EI core transformers rather than toroidal for this purpose even though toroids make for better packaging. Enough online and archived discussions about this already.
Saw a NIB Signal DU-10 on Ebay for about $1200 (retail) and there's pages full of 5, 7.5 and 10 KVA GP step-downs (240V required) under $500. Doesn't sound like cost is an issue for you. Just gotta say... there's good power and better power but ain't no such thing as audiophile power.
http://mysite.verizon.net/vze22yzp/id10.html
For amps in general, never found much benefit for balanced AC. In fact, my Plinius amps are completely indifferent, other than needing a stethoscope to detect any noise, but I still keep them on a 60/60 diet because it doesn't do any harm. My Genesis 1600W bass amp is the only piece plugged direct to "the wall". For class A/B or D amps, even with 10X capacity, a transformer can still be a "speed bump" because those amps recharge capacitors in less than a cycle. Class A amps, with a steady amp draw, are a good load for isolation transformers.
On the other hand, preamps and sources have responded well to balanced AC. In some cases, like the SFL2, which has a power supply larger than many amps, the difference was shocking (sorry, bad pun).
Agree with Zman that multiple smaller isolation transformers are better than one. That is the point of isolation. Do you realize the weight of a 15KVA transformer?
Code issues with distributed (through wall) balanced AC that Equi=Tech has dealt with but that doesn't apply to boxes in room or on the rack.
There's also the running cost. Although they're quite efficient under load, they have an "idle" or exciting current (typically 10% of capacity). Although larger transformers have a lower percentage of exciting current, it's always more.
Gotta disagree with Jeff about the Sola CVS (and MCR) regulated transformers. They are great for their intended purpose but they're noisy and don't respond well to dynamic loads. The CVS series provides less isolation and noise reduction.
Prefer standard EI core transformers rather than toroidal for this purpose even though toroids make for better packaging. Enough online and archived discussions about this already.
Saw a NIB Signal DU-10 on Ebay for about $1200 (retail) and there's pages full of 5, 7.5 and 10 KVA GP step-downs (240V required) under $500. Doesn't sound like cost is an issue for you. Just gotta say... there's good power and better power but ain't no such thing as audiophile power.