Tube Amps Watts vs SS amp


Can someone explain is there is a difference between the watts of a tube amp vs vSS amp, Looking to get a tube amp ,but i see that the watts are much less than the SS amps, So how do these Tubes amps with 25 -70 - wpc drive these high end speakers, I have a vintage pair of AR 9s and 2 mcintosh MC2200 amps in mono (400 WPC) to drive these ,what tube amp will power these under 3-4k new or used, Thanks 
128x128bestbaker
With larger power supply, tube amplifiers tend to play louder than SS with same watt spec.

20 years ago I had Jadis 500(350Watt) which played louder than Krell KSA 150(350Watts at 4 ohm).

Rogue Cronus Magnum II (kt120 100Watt) play much louder than most 100 watt SS amp.

Thomas
I find it interesting that so many audiophiles, particularly those who favor high-powered amps, measure quality by how loud an amp will play.  For me, the measure is just the opposite--how soft can an amp play and still deliver satisfying sound.
Tube W sound more powerful than SS W because tubes distort more and higher distortion will be perceived as higher loudness even if the measured SPL is the same.


Oh my merciful heavens. Please read Roger Sanders excellent white paper on tubes vs solid state. He explains in language anyone can understand why tubes sound different than solid state. Much of what I have read on various fora in response to questions like you have posed is amassed in his white paper. Google his website Sanders sound systems.
With tube amps it is not all about the advertised wpc, the transformers ,power supplies are the key and the quality .
i have seen a 18 watt parallel SET amp with great monolith transformers destroy a very respectable 100 watt SS amp 
by having big high headroom transformers  that makes all the 
difference in the world.