[justinm]

I have an old Melos sha headphone amp I use for a preamp and several classDaudio amps. I'm planing on getting a minidsp10x10 with multiple sub-wooofers and 2-way mini monitors. My question is will balanced xlr cables from the mini-dsp work even though the source components and pre-amp are single ended? Can I use adapter rca/xlr between the pre-amp and minidsp then run the amps with balanced from the minidsp? The reasons for wanting to go this route is to locate the 4 subs in different locations throughout the room and I've also heard that the classDaudio are designed to perform a little better in balanced mode. Thanks in advance for any advice/suggestions

[Speedskater]

Yes, it's easy to go from RCA unbalanced output to XLR balanced input.  As a mater of fact all modern well designed components have balanced/differential inputs even if they have RCA input connectors.

[Davey]

As a mater of fact all modern well designed components have balanced/differential inputs even if they have RCA input connectors.

Uh, no.
The internal input circuitry may be an op-amp with a differential input (or some similar topology) but if your component has an RCA jack connection to the outside world then you have (or should have) an unbalanced input.  I have seen some components where the RCA jack outer shell is floating with respect to signal ground, but this is extremely poor practice...IMO.

Regarding the original query:  Unless making long interconnect runs and/or a possible issue with hum/noise pickup, I think I would not over-complicate things by attempting balanced interfacing with the miniDSP unit.  Start with simple RCA unbalanced connections between everything.  That should work acceptably.
The original question is somewhat puzzling in the wording so I may not be understanding the exact scheme in mind.

Cheers,

Dave.

[Speedskater]

Uh, no.
The internal input circuitry may be an op-amp with a differential input (or some similar topology) but if your component has an RCA jack connection to the outside world then you have (or should have) an unbalanced input.  I have seen some components where the RCA jack outer shell is floating with respect to signal ground, but this is extremely poor practice...IMO.
Dave.

That's what I was trying to say. Sort of.

[DaveC113]

Some light holiday reading... 

http://www.rane.com/note110.html

http://www.rane.com/note151.html

[justinm]

Uh, no.
The internal input circuitry may be an op-amp with a differential input (or some similar topology) but if your component has an RCA jack connection to the outside world then you have (or should have) an unbalanced input.  I have seen some components where the RCA jack outer shell is floating with respect to signal ground, but this is extremely poor practice...IMO.

Regarding the original query:  Unless making long interconnect runs and/or a possible issue with hum/noise pickup, I think I would not over-complicate things by attempting balanced interfacing with the miniDSP unit.  Start with simple RCA unbalanced connections between everything.  That should work acceptably.
The original question is somewhat puzzling in the wording so I may not be understanding the exact scheme in mind.

Cheers,

Dave.

Thanks, for the explanation. I was just wondering since a couple of the subwoofers are going to be over 15'-20' from the minidsp/and other equipment, would running the subs amps in balanced mode with xlr connectors instead of SE from the minidsp outs be benificial? I can probably just position the farthest sub amp about 15 feet away and run 10-15' heavy gauge speaker cable and stick with single ended connections all the way around if it makes everything work better together? Thanks Justin

[Speedskater]

If balanced input & output circuits are available, then it's always better. For longer interconnects, especially when different AC circuits are involved, then it's much better.