Are the XLR outputs of OPPO BDP-105 true balanced?

I think you meant to say: is the analog (output) stage balanced?? Don't know myself, but at the price I'm willing to bet it is not.

True balanced would mean separate complete stages for the plus and minus legs.
No they do not provide separate legs. the balanced output is the usual op amp inverted type.
Nothing wrong with that if it is well implemented.

The output level in Balanced is double the output level on the RCA jacks. Yes, it's truly balanced.

http://www.oppodigital.com/blu-ray-bdp-105/

Sorry Daneilk141, true balanced is not ust the fact that ANY balanced output is twice the voltage of the single ended RCA..
A 'true balanced' would be the signal is implemented internally in a full dual setup, so the positive leg, AND the negaative leg are amplified. MOST current balanced output are NOT true balanced, they are created by a single chip op amp which creates an inverted positive leg, and sends that as the negative leg. So it also doubles the voltage, but it 'cheats' to do so. and thus is not 'true balanced.

Yes but that ploy still does accrue all the benefits of balanced interconnection.