Meridian 506 version..what do I have??

That's an interesting question. Why don't you know? If it never went back for warranty work, my guess is it's the 20 bit version. My 506.18 has the 1.12 version software only because it went back once.

Look of the front faceplate. If it just says "506 CD Player", you have the 18-bit version; otherwise, it will say whether its the 20-bit or 24-bit version. Also, look at the serial number on a white sticker on the back. If it is 1xxxxx, then it has the original laser mechanism and can't be upgraded; if it is 2xxxxx or higher, it has the newer laser mechanism and can be upgraded.

I have a 506 which the previous owner had updated to a 24bit DAC. When I press the "display" button in standby I get "1.12" I don't know if this helps you as I am not really sure if the two (dac and software version) are necessarily related. It might be worthwhile emailing Meridian on this one. As an aside, I love this player. Incredibly smooth and detailed. The 508.24 was definitely better but not significantly to my untrained ears. I'd be interested to hear what you find out.