MikeM
Yes they should be slightly different, but it's tough to compare.
If it's blackface vs blackface for example, they're very similar. The difference really is that the reverb channel on the twin without the reverb engaged sounds better than the clean channel to most ears. The main difference besides that is 6v6 vs 6l6(GC) (Which is actually a big difference, running 6v6s @ 420v is really hitting them hard whereas 6L6GCs can go a whole bunch higher without strain) and larger filter caps(Minimally but it should make a diff) the bassman also has an extra triode gainstage which makes them tough to compare. I think the biggest difference overall would be the tubes ?
Whereas the silverface amps the biasing system looks very different. But yes I once again go back to saying the BFDR is the ultimate amp. I envy those that have them / can afford them ?
AlanRatcliffe
The big difference (at least for me) between the Twin and most other classic Fender amps: it has a solid-state rectifier. That gives it little to no sag when compared to the valve rectifier models, which means it's cleaner and punchier (especially in the low end) with more dynamics.
I don't think there is any one amp that typifies the "Fender amp sound" - there is an overall bright, mostly cleanish sound that most models share, which I think boils down partly to what Leo liked to hear and partly what valves were readily available and inexpensive. However, the different series' (Blackface, Tweed, etc.) each have a different take on it (BF have a scooped midrange while Tweeds have the opposite - a hump in the mids). Within a series, you'll find a more subtle variance between the tone of different models, but that difference came more as a byproduct of the application they were designed for, where power, size and price were the controlling factors.
Then of course, when you add in the newer models, you get even more variation - especially amps like the Supersonic, which was designed from the ground up as a modern high gain monster.
evolucian
i found the gain of the supersonic to be rich and warm. One of the best I've ever had the pleasure of perving over for a few months. The Bassman switch on it is stunning... and the other one too, albeit brighter... i forget which it was...I remember it being two makes in one. The twang on that was awesome too. But I didn't have the money for it and Dozi the bastard came and bought it or it was Gerrie P. Can't remember... now one of them has an awesome amp who's speakers i broke in.... sigh.... the heartache is unbearable. Woe is me...