SS to valve

Those Tannoys @ 92db will work well with plenty of valve aka tube amps; you don't need a ton of power. I haven't heard those Gamuts so hard to compare. Also, many different tube amps have very different sonic signatures. It will be tough for you to get a good idea without doing firsthand listening.
The generally accepted headline would be more air, more natural timbres and a relaxed presentation, with the sacrifices usually being less dynamics and low end tight control of the bass. But these days, both types are getting better and more similar sonically than ever. Perhaps searching systems for similar Tannoys and seeing what amps owners are satisfied with will help you learn from their experiences too.
After having traveled down similar roads with different brands, I settled on hybrid monos that give me some of the benefits of each topology. Cheers,
Spencer

Thanks Spencer. I should have indicated that I'm looking for recommendations. 

Switching from s/s to tubes may not be a step up....  Modern day amps from both camps meet in the middle of sound expression.  Make sure the amp you buy is the one that pleases you most, after trying out others.

Manley Snappers mate quite well with Tannoys.  stringreen is right, I have Tannoy dc8 and am using  a solid state amp from Blue Circle.....it is very close to the middle especially with my tube preamp.  Best of luck in your search.  Regards.....

Although your Gamut is a great amp, it’s massive power ability is wasted on the Tannoy’s as they are very easy to drive.
Gamut specs:

Output power 8 ohm 1 x 250 watt
Output power 4 ohm 1 x 500 watt
Output power 2 ohm 1 x 900 watt

You would probably be better of with a good Class A amp like the smaller XA .8 series Pass Labs amps. Or if tube floats your boat, a good push pull triode mode amp. Maybe even a OTL like the Atmasphere S30 stereo or M60 monoblocks.

Cheers George

Thanks stringreen, carmenc & George. 

George could you further explain the benefits I would gain from using lower powered monos with the Tannoys?

Having only ever used SS I was unfamiliar with OTL amps & now I'm very interested...! How do the Atma-sphere M60 monos compare to the 300B monos from Transcendent Sound?
Are there any other manufacturers who produce good OTL amps?

Your Tannoys are are quite efficent at 92-93db, and with a benign 8ohm load, that’s why do don’t need a 250watt amp that can almost keep doubling it’s wattage all the way down to 2ohms. This is the type of amp that you would use on Wilson Alexias with their down to 1ohm at some bass frequencies loading.

By going less wattage you can get amps that are running much higher in Class A bias (which is better for sound) than the Gamunt can. The first watt is the most important so the more Class A watts you have the better the sound should be that’s why i suggested the smaller Pass XA .8 series.

As far as what I read with the Transcendent 300B OTL monos you only have 1.5watts?? Which sounds very low, With the Atmasphere M60 you get 60watts.
Maybe Ralph from Atmasphere will chime in, as knows his opposition and maybe he can explain what’s going on with the Transendent’s 1.5w

@atmasphere

Cheers George

Thanks for your input George...From what I've seen in your posts you're a very knowledgable man!
I've emailed Ralph...

I was also considering replacing my XP-20 with the MP-1 or MP-3...as long as he can include a remote!

With the efficiency of your speakers in most rooms, the fact is you need power. Given the prior comments here, 60 watts would seem to be adequate in most cases. 1.5 watts OTOH is simply not enough. You would want about 12 db more efficiency to make 1.5 watts practical.

The remote feature is available for both the MP-3 and MP-1.