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...
I have an Oppo 203 in a HT system.  I use the HDMI output for multichannel and one of the SPDIF for two channel
@GOLFNUTZ,Thanks, Your post got me digging...
My 205's manual also say's the same, " 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)."

But thank god I dug in this further and has the above clarified:
"Stereo Signal: To select the audio source that will be processed and sent out through the STEREO and the XLR BALANCED STEREO audio terminals. The available options are:
  • Down-mixed Stereo (default) – The stereo or down-mixed stereo signals are processed and sent out from the dedicated stereo output terminals.
  • Front Left/Right – The original Front Left (FL) and Front Right (FR) signals are sent out from the dedicated stereo output terminals. The purpose is to fully utilize the better DAC hardware originally assigned to the dedicated stereo outputs for customers who prefer multichannel speakers and do not need the dedicated stereo output or zone 2 output. When this option is selected, the dedicated stereo output ports should be used as the Front outputs of the 7.1ch / 5.1ch / Stereo Audio group. The original FL/FR RCA connectors should not be connected."
So if I'm understanding this correctly, if I set the 205 to the 2nd option "Front Left/Right", I can use the XLR's on the 205 for both 2.0 and 5.1 modes.NICE.. :)

Perfect, seems exactly what you want (with 2 less cables no less).

I assume you'll still test the balance or unbalanced switch in this setup.

I would also make sure volume levels are matched with all 5 speakers when using 5.1CH. The XLR output is rated at 4.2 Vrms and RCA output rating is 2.1 Vrms. I doubt it will matter with A51.