Hello everyone! I new to this forum... I'm surprised I;ve not come across it before actually. Anyway I'm in the market to buy a couple of audiolab 8000M's. I have one or two questions regarding them. I have seen lots of references the serial numbers that the units carry. E.g. D or F. This it seems pertains to the year of manufacture. So my first query is does any one know what the differences are between the different versions and what noticable, audiable difference that might have. Secondly. What pre-amps have people tried with these and with what sort of results? Should I look to buy an 8000Q or is there a pre-amp out there that might provide a greater degree of listening enjoyment? Help! Cheers Grant.