Once again, Guitar Player magazine has further answered my questions (well, most of them). In his Gear Shop Talk article, “Max Headroom,” Mark Baier of Victoria Amplifiers compared the pre-1960 tweed Fender amps (floating baffle, sturdy softwood) to the post1960 blackface Fender amps (secured baffle, ply or MDF wood). He said:
The tweed’s natural resonance is largely what accounts for the characteristic, “I don’t miss the reverb” dynamic. Tweed cabs already have an organic “reverb” to them.
In comparison, blackface amps such as the Super Reverb and Twin Reverb came with the reverb effect built in to the amp.
Turn the ‘verb off on a Super Reverb or Twin Reverb and the tightness, stiffness and directionality of the package becomes very apparent. As such, the reverb is quite a necessity on these amps; it really softens this trait and makes them more enjoyable to play.
I’m sure this difference is even more obvious when comparing the standard 4×12 closed back Marshall to the tweed 4×10 open backed Fender Bassman as described in yesterday’s quote from Dave Hunter.