ADAT--diff-- DAT
Blackface adat's 16 bit machine, 48khz sampling rate (you have to slow the machine pitch down to -147 cents to attain CD sampling rate of 44.1 khz) / adat XT 20 and 24 bit machines, variable sampling rate's. CD's or DAT's are what most replication/duplication services require for making glass masters and manufacturing CD's. DAT tape's are compact, machines have digital,analog and optical in/outs, and mailing tapes are less costly than adats. XT's have more options and are probably better in the long run. I have 4 Blackface adats. Bought 1 new $2800,1 used $1250 in the early 90's and 2 recently off ebay, $250 & $175. 1 started eating tapes. Transport motor went bad. I keep 4 back ups on hand. I do not use anything but ADAT Tapes. There are no more new heads for replacement out there I know of. Its $125/ hr in Dallas where I take my machines for maintence (that of which I don't do) and the head removal and polishing takes 2 to 3 weeks because the adat heads have to be sent to Alesis for polishing and Alesis charges $350 for the polishing. Why take a chance?
The ADAT is a multitrack recorder, you can record 1 track at a time ,bounce 1 track to the other without a board, end up with 8 tracks of the same thing and EQ out each one a little differently through a mixing board with a good EQ for a more preceise sound in depth. The DAT is a 2 track / both recorded at the same time.