hi,
By default, imho, CD changers like Sony's should be considered CD transporters and not high-end audio equipment. Their DAC is not good. I recently got myself a Denon DA-500. It was build somewhere in 1994 I think. It converts optical and rca in both ways. The differences are remarkable to say the least... compared to the cd-changers, the sounds are much softer and warmer. At the same listing level, the cd-changers make your ear bleed, while the da-500 gives you music instead.
Be warned however, using 2 linked Sony cd-changers, you cannot use optical out, because only the master will be heard.
Using the regular rca-connectors, I don't think you will be much better off than using optical-out.
I have a question of my own : The DA-500 accepts optical-in and coax-in. The Sony CD-changer has optical-out and RCA-out. Because I'm not allowed to use optical-out while using 2 changers, I have to use RCA. Now - this may be a stupied question - but is there a cable that on the one side has a Red/White-connector and on the other side a single Black-coax connector ?
Thanx