Tube integrated with real bass. Does it exist?

Sorry Inna, I didn't see tube in your request. My fault.

Amazing how many here bit at what is a silly and pretentious question (OK…I'm biting)…but I'll state (or re-state) the obvious: the frequency range of most well designed modern tube amps provide plenty of bass if matched with speakers designed to reproduce it. Also obvious is the benefit of a good sub to any system other than one with a large and efficient main speaker (Tannoy? ZU? Vintage Altec?). If you have the clams for it, the Rogers integrated KT150 200 watt per side is pure muscle…I've heard one…pricey but cool. Tube amps, if they have some cajones in the design, seem to have more muscle than SS amps, but I could be basing that on how they sound…weirdly.

If I were to go with an integrated tube amp to replace my Luxman 505ux (which has much better bass response with my Harbeths than the Rogue Cronus Magnum), I would check these out.

http://www.toneimports.com/lmaudio/501IA.html
http://www.audioresearch.com/en-us/products/integrated-amplifiers/vsi75

http://www.toneimports.com/lmaudio/501IA.html

Its worth noting that they may be all you have to go with but efficiency specifications are quite loosy goosy typically and hard to bank on either way.

Usually, if speaker is small, chances are bass will be limited with most tube amps. Those speakers that can do extended flat bass out of a small box always require more power and current to achieve it. No free lunch here that I have ever seen or heard. If it appears too good to be true, it probably isn't. if you punt on the extended bass aspect of things though, things become pretty easy. Low bass is where all the hard work happens ie large efficient drivers and or smaller drivers and more power/current to move them. Its basically the limitations of physics that cannot be undone even with the best and highest quality designs.