Hello Ron,
Nah, bitstream came much later.
My AA1 has a TDA1541A and a SAA7220.
I think its the mechanism thats been improved.
btw, I've listened to the following recently, Arcam FMJ 23, Arcam FMJ 33, Naim CD5, Naim CD5+FC2.
Out of that lot I prefer the CD5+FC2. But guess what, I still think my AA1 sounds more cohesive. Less 'spotlighty' than the CD5.