Adding Balanced Outputs Psuedo or Real?

[audiomagnate]

I made a small line level device with RCA outputs that my brother wants to try out, but he insists I add balanced outputs. He will be plugging it into his new Audio Research Reference preamp and all he uses is balanced cables. The cables are only a few feet long, so I really don't see the point of inverting the unbalanced signal with an op amp or a transformer. Does this make sense or would I be cheating my brother if I just sent a balanced signal through his fancy cables?

 

[jcx]

balanced audio interface is specifically about balanced Z on the 2 wires, actively driving inverted polarity signal isn't really required, doesn't help with the CMRR of the balanced interconnect except for the 2x larger signal level increasing the S part of S/N

so if you give balanced Zout on the + and - signal, decide what is "correct" in your situation for pin 1/shield (360 chassis connection or RF hybrid, maybe DC ground lifter/loop breaker?), then most of the advantage of "balanced interconnect" would still be there

 

[AndrewT]

use the diagram in Jensen apnote 003 for a passive added output that gives a balanced impedance output that gives all the balanced impedance connection attributes.

 

[billshurv]

Where is that appnote? not found on the jensen site when I took a look.

 

[AndrewT]

I see that jensen have changed their site.
They are forcing me to register before I can see the ap note.

Here's 003 from my HDD and a selection of other well worth reading/saving.

 

[billshurv]

Gotta love how they have no truck with the view that electrolytic caps are bad in the signal path. And given the have measured them they are probably correct!