Bryston pro series SST2 amps vs.r regular SST2 's

Hi All,
Are there any differences between the regular bryston amps and the pro series amps. I'm aking because the pro series amps are quite a bit cheaper.

David Shapiro
The only difference is the pro series includes a wider range attenuator, rather then a two step one.
If you doubt me check over in the AudioCircle site at the Bryston Circle.
I own a Bryston 4B-SST2
If you bought from a pro dealer they would be cheaper just as
the consumer models,you can save quite a bit going that route.