Isolation Transformers

I moved this unit in my second system where I don’t have a dedicated AC line but I also added Aric’s tube preamp to the mix and changed the amp’s power cord around the same time. The system is dead quiet and the bass is decent but I attributed most of that to the preamp and the power cord. I may try doing a comparison with the unit out of the loop using a power strip instead to see if I hear a difference.
Thanks again for all the responses.

Thanks for all the responses. Its technically a medical grade isolation line conditioner, an older version of this unit from TSi Power. They seem to use the term isolation transformer interchangeably.
http://www.tsipower.com/products/isolation-line-conditioners/indoor-isolation-line-conditioners

Looks like they only sell commercially.

“...but it's' not going to regulate voltage.”

Fair point. I said it puts out a constant 124v but this statement was false by definition since I’m not constantly measuring the output voltage. It does however put out 124v the few times I measured the voltage which was roughly 2-3 volts more when compared with its adjacent wall socket. 

^^^^^ Great question, and I think it was unloaded, if I remember correctly. I’ll take some measurement with preamp and amp up and music playing at moderate listening levels.

Took some measurements. The voltage in the adjacent socket is 118.8v. With everything plugged into the transformer; streamer, DAC, preamp, and amp, the voltage out of the transformer is 122.4v +/-0.1 volts without anything turned on. With everything turned on the voltage stayed exactly the same with or without music playing even at high volumes. I had seen 124v in the past but I'm guessing it depends on the time of day where the voltage from the wall socket was closer to 120v. So it looks like the difference is roughly around 3.5-4 volts. On surface, the unit (1400VA according to the label) appears to be maintaining the same voltage regardless of the load, at least in my system.  
By the way, this is what TSi Power says on their website:
"An isolation line conditioner can eliminate the need for a dedicated circuit or expensive rewiring. This is particularly helpful when wiring is old or a tenant doesn’t have easy access to distribution panel boards."