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.
10 responses Add your response
From the description of the BDP-105 at the Oppo website:
The stereo output offers both XLR balanced and RCA single-ended connectors. The balanced output features a true differential signal path all the way from the DAC to the 3-pin XLR connector. By transmitting a pair of differential signals, the balanced output provides better common-mode noise rejection and improves signal quality.So the answer to the OP's question, however it may be interpreted, is "yes."
The reason for the conflicting answers is, as I see it, that the expression "true balanced output" is ambiguous. It could be interpreted to mean that the component's internal analog signal path is balanced ("fully balanced" would be a better term for that, IMO), or it could be interpreted to mean that the XLR connector is provided with a balanced pair of signals, as opposed to the XLR connector being provided with a single-ended signal with one of the two "signal" pins being grounded.
IMO the expression "true balanced" is one to avoid, at least without further clarification of what is being referred to.
In one case in order to provide perfect cancellation both output stages have to have exactly same gain and bandwidth while in the other scenario whole leg of amplification has to have exactly same gain and bandwidth - otherwise common mode noise converts to normal mode noise. It is easier, in my opinion, to match single output stage.
True balanced configuration cancels even harmonics (warm sound) but does nothing to odd harmonics (bright sound).
A P.S. to my previous post, just to add to the confusion :-)
In addition to the possible interpretations I described previously, the expression "true balanced output" can also be used to distinguish between the situation Elizabeth described, where an op amp is simply used to create an inverted output signal (which is sometimes referred to as a "pseudo-balanced" output, although that term also has multiple possible meanings), and the situation where a "cross-coupled" electronic circuit (which may also be op amp-based) is used to mimic a transformer-coupled output. That form of electronically generated output is sometimes referred to as a "true balanced output," even if the internal signal path of the component is single-ended.
See this paper for a discussion of cross-coupled electronically balanced outputs. Figure 2 on the second page has a representative schematic.
Unless there are signal transformers in there, it is not truly balanced. It is a Solid State emulation of balanced. The only way to get truly balanced is to use transformers.
There is one aspect of balanced tht cannot be achieved with SS, and that is the plus and minus signals must be exactly the same amplitude at all levels. Also , no DC offset is allowed. Neither of these is practicallypossible with SS.