Converting RCA to XLR


I currently have an OPPO 205 media player that I'm using for stereo / 5.1 audio play back on an old amp. The 205 has 2 stereo XLR's and also RCA's for all of the outputs. I just bought and is in transit, a Parasound Halo A51. I would like very much to use those 2 stereo XLR balanced outs when playing stereo music, but of course I would also like to play 5.1. The issue is the remaining 205's outs aren't XLR's.

The A51 has a switch located on the back of the unit, to switch from balanced to unbalanced, I'm assuming that's kinda like switching from XLR to RCA. So could I plug all RCA's and XLR's in the A51 (that would mean doubling up the XLR and RCA on the front left and front right) and then manually throw the switch back and fourth depending on stereo vs 5.1? That doesn't seem right.I've also seen:
  • XLR converters that the RCA interconnect cable plugs into.
  • and similary cables with RCA on one end and XLR on the other.
Are these converters and or the RCA / XLR cables any good? Or should I be doing/looking for something completely different?
Thanks for your help...
divby0
Interesting, I'm almost tempted to try combining the 2 types of outputs on my BDP95 to see what happens (it would really be a pain to set it all up just for the sake of testing something). I've only ever used the BDP95 S/PDIF to HT processor, never for audio as that's all done on different hardware. The plastic caps on the 7.1CH connections have never been removed.
Not entirely sure what the following really means.

From the BDP95 manual:

" NOTE The STEREO AUDIO OUT terminals automatically down-mix the multi-channel audio source into the stereo signals. However, STEREO AUDIO OUT will NOT be affected by the “Down mix” modes and other speaker settings in the Audio Processing of Setup Menu (described in the page 70)."
Thank you all for your input. It looks like I’ll be doing some testing when the new amp arrives. I did buy the Cardas XLR/RCA adapters and my hopes are when playing 5.1, that they’ll at least sound as good as if I was using straight RCA’s from source to amp and they won’t have any negative effect when playing stereo. I really don’t want to have to get off my ass and awkwardly reach behind the amp, groping for this balanced/unbalanced switch, every-time I change from 2.0 to 5.1 ugh!

So I’ll be doing the following tests:
  • Stereo using just 2 channels XLR (switch set to balanced)
  • Stereo using just 2 channels RCA (switch set to unbalanced)
  • Stereo using all channels RCA (switch set to unbalanced)
  • Stereo using XLR (Front LT, RT) and RCA with XLR adapters for remaining channels (switch set to balanced)
  • Stereo using XLR (Front LT, RT) and RCA (Front LT, RT) with RCA for remaining channels (switch set to unbalanced)
  • 5.1 using XLR (Front LT, RT) and RCA with XLR adapters for remaining channels (switch set to balanced)
  • 5.1 using XLR (Front LT, RT) and RCA (Front LT, RT) with RCA for remaining channels (switch set to unbalanced)
  • 5.1 using all channels RCA (switch set to unbalanced)
If you’d like, I could report my findings if anyone is interested.

@OP, 
There are Jensen adaptors available for just this purpose. 
A good person to PM would be Ralph Karsten (atmasphere). I know he would be able to give you good advice concerning this.

Lastly I, for one, would be interested in your findings.
B
Did anybody mention that XLR outputs are often higher gain than the RCA outputs. That can add noise to your system and sometimes you have to pad down the signal. Depends on many factors.