I had the original volvo changer but it went bad so after much research I installed an Alpine 611 Changer directley to the 810 head unit and to my knowledge the Alpine 6 disc changer is the only one that will work because it uses the 6 radio "memory" buttons to change between the disc's. BTW you will need an adapter to to connect the Alpine changer to the head unit.

I had a 10 Disc Sony changer in my honda and wanted to move it but had to leave it for my wife :( But alas I have gotten used to the 6 disc ver since I mounted it in my glove box and just bought multiple cartidges with multi colors which is cool becaue I have multi genre's of tunage in each one.

By the way you will be shocked at the difference between the radio and cassette sound qulaity and what the CD changer will do I was blown away.

Good Luck