Audio Research ARC Ref 5 versions?


Hi,
Would anyone know if, apart of the obvious SE version, there were differences between earlier units of the Ref 5 and more recent ones?
If so, when was the "cut" between earlier and recent?
Thanks.
amuseb
Ritmo did you have a Ref5 or did you make the jump from the LS27 to the Ref5SE? And I want to clarify, I was not knocking the LS27. I have an LS26 and am very happy with it, but the LS27 is in my crosshairs. The Ref5SE is not in my budget unless I wait for a used one. I think that between the LS17SE,LS27 and REF5SE as mentioned Audio Research is the one to beat.
I don't own a Ref 5 but think about it. Live in US. Will check with ARC on upgrade cost. Might be worthwhile to get a used Ref 5 and then upgrade. That is if I become convinced it exceeds SQ of my noble Wyetech Opal, which would be a major accomplishment.

Neal