I have heard that the Fender Bassman has a true Fender tone stack and the Rumble does not.
Is this true and what are the differences? I know @G-Dog has both...
You are so correct. I had to dig a bit to get past all the tube amps but I found the solid state ones. One of them actually piqued my curiosity - the hybrid 500W Bassman head. Two tube pre and the power section Class D. Do you know anything about that one?
Well, there are all manner of things written about a "true Fender tone stack":
But, IMHE, I find the difference to be a Vintage vs Modern "feel". The Vintage channel of my Bassman 500 is a very enjoyable passive cut-only 3-band EQ, with pull "Deep" on the Bass and pull "Bright" on the Treble. But, it just seems harder to get the tubes involved on this channel at lower volumes. It seems to take more volume than I sometimes want in order to get the tone that I always want.
I think my ears are more tuned to the modern "feel" of the active Overdrive channel on my Bassman 500 with the Gain controlling the preamp tubes' distortion and the flexibke sweepable Mid Frequency & Level, in addition to the "Deep" & "Bright". Or I'm just lazy and like getting the tubes warmer at lower volume this way. At practice levels I can really feel those tubes doing that thing they do!

And, perhaps it's the active 4-band EQ, with Overdrive, of my Rumble 500 that I like, too. Even if it doesn't have actual preamp tubes, like the Bassman 500 does, it does a fairly creditable job of emulating that tone. And at gig levels it's close enough for me!
I hope that helps you, Souly & Thump.
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