Balanced But Not Fully Balanced

@almarg and @atmasphere

My sincere thanks to both of you. Very informative and rather prompt too I might add.

I have since asked Musical Fidelity. Their response:

"No it isn’t fully balanced. It is converted to single ended to work with the rest of the amplifier."

The aforementioned being the case, could you advise then whether or not it would be preferable to connect the amp to equipment that I believe purports to be fully balanced (specifically Emotiva ERC-3 and Oppo UDP-205) via XLR or RCA? I currently have it connected via XLR. Sounds great either XLR or RCA. Just wanting to know if theoretically better to connect via RCA when connecting a true fully balanced piece of equipment to a non-fully balanced piece.

Fully balanced equipment is always more expensive because the design has  separate circuits for the + and - portions.....  XLR connections on equipment makes for a selling point.  If you have both - try them both and see if you can hear a difference.

@gdhal
Hi Hal,

As you are aware, the Oppo player is clearly described as featuring "a true differential signal path all the way from the DAC to the 3-pin XLR connector." And as you indicated the Emotiva ERC-3 purports to be similar in that respect. However despite the ERC-3 being referred to as a "Differential Reference (TM) CD Player/Digital Transport," and despite suggestions in its manual that its balanced analog output is "generally preferred," IMO there is enough ambiguity in its descriptive literature to leave me at least a little bit uncertain as to whether its analog signal path is in fact fully balanced. Also, we have no way of knowing "a priori" whether the net result of the tradeoffs I referred to in my post above dated 9-20-2012 would work in favor of the balanced or unbalanced inputs of the M6si integrated amp.

So the only way to be confident of the answer to your question would be to try both players both ways. Which it sounds like you’ve already done, with similar results in each case. But if in fact there is any difference, given that the M6si has only a single XLR input, and given that the Oppo can be said with certainty to have a fully balanced analog signal path, my guess would be that the best odds of obtaining optimal results would be if you were to connect the Oppo via XLR and the Emotiva via RCA.

Best regards,
-- Al

@almarg and @stringreen 

Understood. Thanks!