Tube amp with SS like bass

Of the ones you mentioned the Butler would be my pick. I heard it at RMAF and thought the bass was very good. It is a hybrid design and OTL, no output transformers.

That being said I would generally agree with the others who indicated you will have to set your budget higher to attain the goal.

audio by van alstine has hybrid amps with the most expensive being $1800 and in the 200 watt range.

I don't know how much power you need, or what your trying to drive, or how big your room is, or how loud you want to go, but, Audio Research and VTL have the reputation for offering better bass than some of the other lower priced tube competition.

Tube audio design 1000 monoblocks- 100 watts per channel. i have the 60 and it drives my Vandys(86db) with ease...

Second for Audio by Van Alstine. Although his most expensive hybrid (the Ultra 550) is over $2K, the Ultra 350 is $1850. I would strongly urge you to try it out. AVA is direct sale and you'll have 30 days to see if you like it. I think you'd be pleased with what these amps can do. Solid, quick base with excellent articulation, and a midrange and high end that is many times better than the price. It can also drive tough loads.