I can't read schematics or layouts in such a way that I could have a clue about what an amp sounds like... I just saw this amazing Band Master. A 5U4G, a couple 6L6s...transitional model with 6SC7 crossed out on the tube chart and 12AX7 written in. 15" speaker. All the same as my Pro. Funny that Fender even sold these models at the same time. Anybody know the difference?