What is the best sounding CD Changer.

A Squeezebox Touch..

Anthem CD-1

I had one of the Sony ES 400 disc changers and it sounded passable, and it played SACD's (which sound pretty darn good actually), I asked a couple of the modding shops about upgrades, and they were very eager to do it, but I thought it could be putting bad money after good if the changer mechanism went out.

I have to take exception with Metralla on the Sony SCD-C333ES, and the 555ES. Having owned them, they may have been great in their day, but I wouldn't have one today! If you look carefully at the ads for sale of them, there's always something wrong with them. Either they don't play discs correctly, or the transports have to be replaced, etc. I bought a C333ES from a very reputable Audiogonner (name withheld) and the transport had been replaced by him. Four months later, the whole front display went out, and Sony said it couldn't be fixed, so it was off to the garbage can. IMHO, these 2 models are not reliable.
I now have, in addition to my McIntosh MVP861 player, 3-Sony DVP-NC685V universal dvd chagers that play all formats, including SACD, and for 4 years now none of them has skipped a beat. The 5-disc carousels are quiet, and work great. AND they can be had rather cheaply. Sony makes several models that will fill your bill.

Computer + iTunes. You probaly already own one, so add a
DAC and a cable and your off to the races.