There are 3 mint shape but used Hammond 10Kva 120V/240V input and 120V/240V output transformers, with screen/shield/drain wire on fleabay right now.
These are excellent choices for taking your ENTIRE system to an ENTIRELY new level of quality.
For actual dedicated music freak audiophiles, only.
Works best in the USA and Canada, where we have single sided AC.
You don't see this much any more, some of us are getting wise and grabbing them fast.
http://cgi.ebay.com/Hammond-Power-Super-...=item1c0ff63e75
In the pictures in the auction, you see the wiring diagram, which says it all. This is the exact kind of puppy you want.
120/240 input, and 120/240 output, but with the critical screen wire on the core, as well. this can be rewired for balanced AC output,and derated to about 55-60% of it's original 10Kva rating.
This is more than enough for most audio systems. The 225lb 'skid ship only' part --- should give you a hint. There ain't no substitute for cubic iron and copper, when it comes to this stuff. The massive transformer means it is capable of clean dynamic levels with low compression of those dynamics, which is key. You see the smaller ones in the 75 lb range, and I go 'feh!', gimme some real iron, for some real headroom. These particular Hammond units are big enough to run all the outlets in a given audio showroom. You wire it in at the panel and then run all the outlets in the audio room into it.
My own AC balancing transformer is about 500+lbs. and it was over $8k in the early 1990's..and I bought it used for $400. It will still be working 50 years from now.