Amps don’t make good bass. Speakers create music, including bass response.Amps control the speakers, especially the bass with damping and current, if not you’ve got crud.
Another vote for Manley amps. Not always with the same speakers but I've owned several tube amps and believe Manleys are at the top of the list.
Of course that is a generalization. Some other amp with a particular speaker might be as good or better. But my point is to try one of the Manley lineup at your particular power and price point before deciding.
Why is it that everyone's own tube amp makes good or the best bass?
First of all I think we are really talking about mid bass and up. Let's talk about 100 Hz down to 18 Hz. This is subwoofer territory and I have yet to see a subwoofer powered with tube amps. Part of the reason is packaging for sure as it is harder and more expensive to incorporate a tube amp into a wooden box with a furiously vibrating linear motor. But still. My subs are passive and I use QSC monsters to drive them. The thought of using a tube amp has never occurred to me. Would the ARC Ref 750's do just as good a job? Hows about the Carver Silver Seven?
It would take that kind of power to run a digitally corrected sub. Pretty expensive way to do it but would it work well? My intuition says no but in reality I have no idea. Would be fun to try.