Isolation transformer

I use an Equi-Tech Model 20 in my bedroom system. It is cool to the touch and does improve the sound in the areas that Charles1dad described. I upgraded to my current power filtration system (that can be seen on Audiogon listed in my systems http://cgim.audiogon.com/i/vs/s/f/1304179372.jpg) that I use for my major Audio systems because of improved performance in all areas.
My current power filtration system (and I’ve used it for at least seven years) consists of two Exntek Extreme Isolation Transformers (5 KVA each) that feed into my Audio sub-panel. The isolation transformers do run warm to the touch (96 degrees F and produce 55 dB of sound with the reading taken within one inch of the transformers). The noise and generated heat doesn’t bother me because the power filtration system is located in the basement.
I hear greatly improved musical response in all areas with no major side effects other then the production of some hum, slight heat and of course any isolation transformer is going to consume additional electricity.
I think different brands of isolation transformers produce different results and most likely are somewhat system dependent. What works well for one audiophile might not produce the same results for another. The beauty of my power filtration system is I purchased the transformers used and did all of the labor myself. Total cost was well under $1000 and the results are excellent.

I think an Isolation on dedicated lines is a good idea. In an isolation transformer the output winding will be isolated, or floating from earth ground unless bonded at the time of installation. Secondary neutral to ground bonding virtually eliminates common mode noise, providing an isolated neutral-ground reference for sensitive equipment and an inexpensive alternative to the installation of dedicated circuits and site electrical upgrades.

An isolation transformer allows an AC signal or power to be taken from one device and fed into another without electrically connecting the two circuits. Isolation transformers block transmission of DC signals from one circuit to the other, but allow AC signals to pass. They also block interference caused by ground loops. Isolation transformers with electrostatic shields are used for power supplies for sensitive equipment. Isolation transformers are different from auto transformers in which the primary and secondary share a common winding.

I installed a Richard Gray SubStation Pro, 220/110 stepped down, balanced power ISOTransformer, on a dedicated 220 V line and havent looked back. A measley 50 watts of parasitic power on 150 pound of windings is no issue for me. I also have the RGPC 600S parallel choke connected for the complete ISO Gray system. I also have my system ultimately "powered" by one PS Audio Premier dedicated for each monoblock, and P500 for all source components. Two different technologies complimenting one another. Installation of the Gray system,in my case,was based on sound electrical engineering principles, not percieved psycho-acoustical benefits, which is subjective and component based. However I'm sure there is some sound benefit, but that's not the main reason why I purchased it.

My Topaz is a 2.4KVA and I did not see any taps to adjust the voltage. BTW the Topaz Is a balanced output with a whopping -146db in common mode rejection (neutral to ground)(forget what normal mode was). I used a clamp on amp probe to measure the current then multiplied by the input voltage to get the 90w. Now my Topaz does have a slight hum (wish I could teach it the words intead).

It`s refreshing to read the posts of other balanced transformer owners who`s experiences have been as rewarding as my own(note the various brands also). This does represent good science/engineering priciples put to use to significantly improve the sound and enjoyment of one`s audio system. A well designed balanced isolation transformer(of proper size for the job) is definitely money well spent.