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.