I have an A77 and it is a great machine, mine was untouched so I had a long list of parts to replace on it (mainly capacitors). The B77 used some of the earliest op amps in its signal path (upc741's I think). I used to have a TD20A and it was a superb machine, on pure sonics I would pick the Tandberg but there are many more B77's around and they are easier to service. I had an RT909 which sounded like a cheap CD player to my ears, I've not checked the schematics but there might be more early op amps in there as well (there was in the RT707). David.