Suggestions on capturing balanced audio?

[swiego]

I have a set of BetacamSP tapes to capture. I have a couple of excellent decks - a PVW-2650 and a UVW-1800. (Both are excellent and have less than 100 power on hours!) Unfortunately my capture solution (ATI 650) requires unbalanced RCA audio and both of these decks only offer balanced audio out the back using those 3-prong connectors. Not looking to put a ton of $ into this (purely hobbiest/personal interest) but would like to know what options I have.

The UVW-1800 has an RCA "audio monitor out" that I'm using but it's single channel/mono only as far as I can tell. Worst case I can live with it but the tapes are stereo and I'd love to get access to the stereo track. I tried running headphone out to the capture card and attenuating levels as best as I could but as expected it did not work so well.

Also, IF anyone has experience with high quality BetacamSP (these are studio/set tapes) I'd welcome feedback on how to improve the capture tool chain. My test captures are with s-video to the ATI 650 however it occurs to me that these tapes may well have higher resolution than s-video and I ought to have/use a capture solution that accepts the component outputs on either deck. (That said, the s-video captures are absolutely incredible: I've never seen analogue non-HD tape look anywhere near this good.) However I am not up to date on a good capture solution that would support 480p component input with good support for lossless capture.

My preferred process is lossless capture in Virtualdub to huffyuv/lagarith/x264vfw (it's varied over the years) then editing/re-encoding to final form. I'd like to keep the process intact.

Any help that can be provided would be appreciated!

Example capture: https://youtu.be/Nhahi1IRbIo

Another entertaining one: https://youtu.be/B1BfyUE4upc

[Cornucopia]

What's your budget?

Scott

[swiego]

Flexible, potentially, depending on the options. In theory I could over the long haul sell one of the decks to mitigate the capture solution cost.

[pandy]

You can go from balanced XLR to unbalanced RCA with loss of 6dB
not a problem i assume nowadays... anyway - always you can use balanced to unbalanced converter such as transformer - perhaps Jensen http://www.jensen-transformers.com/product/pc-2xr/ or similar HQ audio balun or modern active converter - for example something based on http://www.ti.com/product/ina2134/description or more traditional design.
You can also capture audio on 4 channel input card - then you can perform balanced to unbalanced conversion in digital domain (quasi differential) - you should be able to improve overall SNR by 3dB.

[Cornucopia]

Plenty of cap cards/boxes that accept balanced audio directly, also (both V+A and Audio-Only).

Scott