TVC Promethius versus Bent

What are the theoretical beneifts/disadvantages between autoformers and transformers?

From what I've read,the one advantage of the TVC is that it provides galvanic isolation, an autoformer cannot.
Will this make a difference is sound for better or worse..I have no idea.

Autoformers have been available for some time, John Chapman (BENT) and other premier passive TVC cos chose to use the S&B transformers; I have to believe there was a reason for that. Not saying the autoformers won't make great product, but it seems they were not the first choice when S&Bs were avaiable to the open market.

I will agree the S&Bs are classics. However, the Slagle autoformers by Intact Audio enjoy a pretty good if not somewhat cult like following. I learned recently that Jeffrey Jackson at Experience Music utilizes them and I have seen a couple other boutique manufacturers using them in their demo set ups at audio shows. Are they going to be as good as the S&B. Not sure, but I'd like to find out. John Chapman mentioned on his forum that if he couldn't get the new TAP to sound as good as the S&B version he wouldn't bother with it. Seems the custom wound autoformers (and John used custom S&Bs as well) are stacking up just fine.

Wired up my own TVC, using S&B mkIII's. They can be set up as autoformers, using only one side and I did try that after reading that method was better, espescially for lows. I didn't notice much difference but I can understand how it might help if impedances and voltages are less than ideal. I preferred to have the isolation and balanced input/output. You need two autoformers per channel for balanced operation. I'm pretty sure that's how the Django does it.

TVC's: It's fun to scare somebody by unplugging the ic's while music is playing. Don't try that at home, kids.