After comparing schematics between blackface era Pro Reverbs and Super reverbs, I'm a little curious about why they are identified as different circuits (AA165 vs AB763). Other than some slightly different component values in the tone controls, and slightly (20 V or so) lower B+ in the Pro Reverb, there does not seem to be any other variation. Am I missing something? Are the characteristics of the output transformers wildly different (apart from impedance matching)? Is one circuit more robust than the other? I guess the real question is: would a healthy Pro Reverb through 4X10s sound distinct from a healthy Super Reverb through 4x10's (proper respective cabinet loads, of course)? Thanks for your help.