Hi Bob,
One difference in the original and later model is the redesigning of the circuitry for a more realistic Dobro sound. At least that’s what it says on the Super Bro 2 I have.
The other change is a full bypass switch that gives you the true guitar sound, whereas the original models went from the Dobro sound to a guitar sound with MatchBox circuitry. Also, the Super Bro 2 has the conventional out to the pot type volume pedal, and then by using certain type of cable, has a means of tapping into the power supply of the Goodrich AC volume pedals.[This message was edited by Buddy Emmons on 29 September 2003 at 11:35 AM.]