Your combination:AC isolation/condition devices

Ngjockey,
"Politely"-- A step down transformer is not a "balanced transformer" and will not achieve the same results.
What do you mean by "very high current requirement"?
Please identify the brand & models you suggest and I will research & post results. Thanks

Any dual core, 480/240-240/120 transformer can be wired (creatively) for balanced AC output because the secondarys are out of phase. Pretty much everything over 1KVA is dual core. If you wire 240V to the 480 primarys(H1-H4), you get +/-60V (referenced to ground) on X1/X4 and connect X2/X3 secondarys. Simple stuff, at least in theory. Transformers can be finnicky. How do you think Equitech got started?

Very high current meant 20A continuous for dual amps, including derating by half for balanced AC output.

The brand I got is GE because this model was fully potted but I have no aversions to any brand, with the possible exception of the Cutler-Hammer aluminum models. Just have to check if it's shielded. It's big and ugly but that's okay in a closet.

Like this: http://cgi.ebay.com/GE-Transformer-5-kVA-5kVA-240-480-120-240-9T21B1004G02_W0QQitemZ370097256785QQcmdZViewItem?hash=item370097256785&_trkparms=39%3A1%7C66%3A2%7C65%3A10%7C240%3A1318&_trksid=p3286.c0.m14

Ng, thanks for input.

I use an isolation Transformer, then passive parallel filters, then a 193L choke wired into the IEC end of my power cord, to my CDP and my Dac. Great results!!

Thanks Benie, what does the choke do?