Tube Amps With Good Bass Qualities

Yes Ralph, I remember my father's Bozak B302A's driven by a ST70 they had loads of bass. By the way what are the woofer's in your speakers? Are your enclosures vented?

Bob, the smiley face was to indicate that I was kidding. I was simply responding to his comment about not wanting to mention other manufacturers who he seemed to think were inadequate to some degree. Ralph does not need to make any enemy's in this business and remaining politically appropriate is important especially where humans are concerned. IMHO they are vicious animals. Lighten up!

Thanx Ralph,
I think you just want them to recommend your amps:)))
I hear you about the financial aspects of the audio business. Not any different from any other consumer oriented activity. I include medicine in that category.
Atma-Sphere amps are expensive because a human has to sit at a bench with 13 rolls of colored wire and a soldering iron hooking up one wire at a time on an awful number of tube sockets. There are no circuit boards, another profit increasing approach. I would rather support an American worker than a Taiwanese robot. There are many solid state amps of similar power that cost a lot more although the MA-3 is seriously up there. (twice as many tube sockets)  

Thanx Ralph. So why do you think so many manufacturers make low impedance loudspeakers? 16 ohm speakers are a rarity. With ESLs you don't have much choice and they all pretty much do the same thing as capacitive loads. But, dynamic speakers could be designed with higher impedance. Maybe it is a marketing problem? 
I was looking at specs and I noted the ARC Ref 750 had a slew rate of 20 volts/msec. Your amp is 600 volts/msec. Why is yours so much faster and how does that effect the sound. 
Next silly question. If you were using two 8 ohm drivers in a subwoofer would you hook them up parallel for 4 ohms or series for 16 ohms and why?

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.