Help Revox or Studer CDPs as transports???? Anyone??

Hi,

I have a Revox B226 and a Studer A727 CD player. Both units are older (80's? Early 90s?), but both are built like tanks. I think they'd make good transports, but both units have TWO RCA digital outputs for left and right chanel. Huh? Is that some old technology that never caught on?

The Studer A727 is a professional model and it also happens to have one XLR digital out. Is this something that I could use as a digital out, or is it's signal too high (due to it being a pro model)?

I'm stumped. Any info would be appreciated.