question about Balanced signals.

mashif is correct. You would need the first balanced device to have a transformer at its input so as to convert the SE input to balanced.  It would then pass a balanced signal to the downstream balanced device.  But most often, the inputs on balanced devices that can also handle an SE input will simply amplify the SE input; the negative phase is internally grounded for SE and the positive phase (of the balanced circuit) carries the signal.

Hmmm.  I've not come across that before.

What is the purpose of a balanced circuit. If you want it to reduce hum and noise you need a differential input. The signal does not have to be differential but both legs need to have the same output impedance to ground. The input must have the same impedance on each leg relative to ground but should be lower than the input impedance of the driven device.

All of those criteria are met in a proper balanced circuit. 

Dear @dukebdevil :  I have  serious  doubts that your amplifier be a TRUE balanced design as you posted. Please read these:

" The voltage gain (into 8 ohms) was 28.4dB via the unbalanced RCA jack. This is slightly on the high side for a THX-certified design, but 6.7dB lower via the balanced XLR jack, which is very unusual. "

That was measures by in real time by STHP review ( J.Atkinson. ).

Additional to that in the manual operation Rotel stated:

" Rotel's balanced design. "

A true balanced design is only that a true balanced design but not Rotel's or Luxman's or whatever manufacturer name.

I think could be better that you forget about your OP with this amplifier.

R.