unusual adapter, balanced?

[jondog]

I went to a flea market and bought some used cables. One of them was, I thought, XLR -> Stereo 1/4" male, a balanced cable. When I looked closer at it I saw that the 1/4" end was actually an adapter converting a male RCA to balanced 1/4" male.

How can this be? What is this adapter for? As far as I know, you can't have a balanced RCA plug. Am I correct in thinking that, despite the XLR on one end, this is an unbalanced cable and that the adapter cannot rebalance an RCA plug?

The only thing I can think is this adapter might work like a Y adapter, sending a mono signal to both left and right. I've never seen one of those before, usually you have to buy a Y cable.

[brianrost]

More likely it's just a balanced to unbalanced cable.

The - of the XLR is either floating or shorted to ground (easily determined with an ohmmeter),

[jondog]

Yes, I've figured the cable is balanced XLR to unbalanced RCA. My question is about the RCA to TRS 1/4" adapter. I've never seen one of those, and I think it's odd because if you want to go from a balanced 1/4" jack to an unbalanced RCA, you don't need the 1/4" to be TRS, you just plug in a regular 1/4", right?

So, to clarify, what is a female RCA <-> male TRS adapter used for?