Isolation Transformer and Subpanel recommendations

Thank you for the help and pointer; we can get 240V here up to the house but given it's US, it has to be broken into 2 120V phases inside the house. I'll check out the link you sent.....thanks!

Thank you very much for the response!

Jea48: the wiring in our houses here is 120V and 240 comes into the house and is split out normally. I did have an error in my response in that we are not obligated to only have 120V here. I currently have a 240V line to the kitchen where an old electric stove used to be, another for a heat pump, and a 3rd for the dryer to the laundry room. I could choose to run a 240V line to the attic for an isolation transformer if I had to. For that matter, I could also choose to drop an entire 2nd house circuit immediately after the meter and skip the main breaker panel altogether; my response was more thinking of limiting the invasive electric/structure work that would be required here. My apologies for the confusion my original response probably caused...

Jea48: Thank for the help and advice; my plan is to install the transformer in an adjoining attic over a garage where any humming from the transformer will not be hear and any heat will dissipate. The attic does get hotter in the summers (have thermostat-controlled fans on either side of attic) but overall I think is the best option as I can also have a platform built to bolt the transformer to in the attic as well as investigating any vibration damping solution I might need to ensure the results are optimal.

The main electrical panel is in the laundry room, on an inside wall but adjoining the garage....I was either planning on mounting the new subpanel there or in the attack adjoining the room that has my system.

Thank you very much for all of the information! I could definitely mount the new sub-panel in the garage and then go straight up into the area adjoining the audio room. I currently have a 100 ft run of heavy flex conduit for my dedicated circuit; I had an electrician pull individual 5-9s copper runs for positive, negative and neutral through that new conduit 4 years ago so that part is already decided. There is only 1 dedicated audio system 20-amp circuit in the room. The dedicated circuit feeds a Purepower APS 2000 and distributes power to my entire system.

End result is better quality power to my system; the dedicated circuit, rebalancing the house panel to make the dedicated circuit the first one off the main, all other high current circuits on the other leg/phase of the house panel, good quality wiring from the main panel to the room, cryo'ed Oyaide R1 outlets, etc... has taken me a certain amount of the distance but I'd like to separate from the house panel totally and improve the quality of power to the room even further.

individual copper runs pulled means individual insulated strands pulled through the flex conduit for positive, negative and neutral (ground)...

The run to the audio room would still need to be 100' as moving the panel to the garage would be a minimal change as the laundry room where the house panel is today is right next door to the garage; I might be able to save 10' or so but the difference is small by moving the panel. (The electrical main to the house itself is also right outside the garage and only about 20-25 feet from the existing house panel location.

Do you have your system posted? I'd like to see/know what you have going for power as you clearly have alot of experience in this area.

Thanks!

Gbart....thank you very much! If memory services the Torus units have their own isolation transformers built into them so this would accomplish more than one goal at the same time. Equitech also makes a high grade all in one panel that has an isolation transformer, EMI/RFI filtering and an isolation transformer all in the same unit; don't know what this costs but it seems like there are several ways to accomplish all this that people have utilized with great success.

BTW...in talking with an audiophile who knows a hell of a lot more than I do on this, it became clear that some of my responses and my not being an electrician have caused confusion on the thread. Apologies all around for this...
Thanks to all of you who tried to help. I've pieced together (with Arnie's help) the essential points I should be chasing if I make this modification and definitely appreciate the help!

Jea48: Thank you VERY much for all the additional information; I've learned a lot by starting this thread! The only word that comes to mind is "Wow!" concerning your level of knowledge. I will check with a good licensed electrician when proceeding with this next phase of system evolution. I'm currently starting to read alot on Controlled Power Systems and Topaz isolation transformers and SquareD (?) breaker boxes plus related topics. No rest for the wicked when it comes to the pursuit of great music listening experiences :-)