I decided to try some WBT RCA's, so I got a set of WBT-0114's.
They are rated at 75 Ohms, (donno if that holds up in court) so I use them on my SPDIF cable.
They come in sets of four, so the two others went on my, not yet complete XLR to RCA adapter, for my headphones.
It is made using wires from a Mogami W3080 110 Ohm AES/EBU cable, it has nice thick insulation on the wires, perfect for light weight wirebraids.
Here are my K240DF's, they are also cabled with braided W3080 wires, and Neutrik XLR (four pin, silver plated).
So why not put RCA's right on to the DF cable?
I have several reasons, it is all about cable management.
I plug the DF's in to my 18k, the XLR connectors make it easier to plug and unplug them, and XLR's don't short the preamp outputs when unplugged, like TRS's do or disconnect the shield before the conductor like RCA's.
Also, to avoid pulling on the RCA connectors, I have the XLR's wedged between the 18k and the table, so they take the stress, Neutrik XLR's can take quite a beating if they have to, and are cheap.
I use the DF's with both mini-jack and RCA, so I have to make an adapter either way, I chose to use the connector that works best for the purpose.
With four pins, they are ready for both single ended and balanced use.