Best CD changer...as a transport?

I use a Sony DVP7700 for a transport and a Monarchy 22-A DAC. Sounds great!

If you mean juke-box style changer, I'd go with a Sony ES changer. The model numbers change all the time, but they can be had new for 300-350 dollars and hold 300 CDs.

Also in this category is the Denon DCM 370 with HDCD already on board. Can be had for around $300.00. If you want use the MSB DAC Link III for around $400.00. Dont buy the HDCD option from MSB as this is already on the Denon. But the upsampling option is worth considering at an additional $199.00. Should be the ticket your looking for.

try a CAL with digital outs, probably the best multi disc transport your going to get

If you are talking jukeboxes, I'm not sure you're going to hear any significant difference using the digital outs. Perhaps with a higher end piece like the Denon 5000. If you are using solely for party/background (non-critical listening) I'd go with a cheap changer and your DAC. If your DAC only has one digital input, save it for a good single play CD transport, and get a little better changer and use its analog output. I think the Sony ES, Pioneer Elite, and above-mentioned Denon have some of the better analog outs. Don't even think about a jukebox without a keyboard input - major PIA. If you want a five-disc, OneCall has the HK 8550 right now for 200 - dual 20-bit BB1702's, HDCD decoding - should be the later models with the quality problems fixed. The previously-mentioned (Marantz, Parasound, CAL) are good choices as well as the Adcom GCD-700. Good luck!