Sub panel & isolation transformer voltage

Is there an advantage hooking up 240V to the IT then stepping it down to 120V to the sub-panel or is 120V straight good enough.
A great question for Sean or someone else knowledgeable. I hope they answer!
I have been experimenting with 120v (vs.) 220v to 120v. I'll get back to you and let you know.
I have arranged my panel so that loads like the dishwasher are on the leg that is not running the audio. Similiarly the fridge, washer, large motors that kick on by themselves. You have three lines coming to the house- one neutral and two hot. Put the two hots on one circuit and you have 220. Only one hot is 120. So I keep noisy junk on the other leg (other hot). Of course, you are still connected to your neighbors junk.
"Of course, you are still connected to your neighbors junk"
That's where the Isolation Transformer comes into play.
Of course...but that's not what you asked. Going 240 all the way and then stepping down at the subpanel or going all the way amounts to the same thing. If it's a large house, and the stereo is far away from the main, you go off the subpanel. The only reason to do this is that the resistance is far less through the thick wires going to the sub. If the stereo is near the main, it's better to go straight. Either way, eventually you are connecting to your neighbors trash, so you need the I.T. HOWEVER....what problems does the I.T. cause,if any? Have you A/B'd with and without? What kind are you using?
I haven't installed an IT in my new house yet, but years ago I did have one and the difference of quality was quite noticable; deeper, cleaner bass, easier mids and less harsh highs. Much better image on the TV also, better voltage control it seems.
Homer, please post when you install your new IT, what model you end up getting, and the sonic results. Thanks!
Sure will, it'll be about a month or so since I'm doing the whole room from scratch, about halfway through now. I'll post some pictures if I figure out how to!