Which of these Amplifiers do you think will deliver the smoothest ,sweetest sound to live with?

It would be nice to know which amps are you actually considering - there are 10W class a valves - and there are 10W CLASS A VALVES!

"Smoothest and Sweetest" - generally describes a tune/valve sound. If your speakers are VERY efficient, and you do not listen very loud - can't beat 10w Valve Class A (probably SET - Single Ended Triod). If you need more - go for more powerful tunes, Class AB.

Come on guys! Don't be crazy! If you are amplifying a guitar, tube( valve in ENGLAND) are the way to go. They color the sound, so they don't sound thin. If accurate music production is what you want, I can go buy a 20wx2 solid state for $50 and to match the THD and S/N ratio a 20x2 tube amp would cost $1000 or more. Tube amps can sound good, if you want to shel out thousands, but solid state will still be more acurate. Do you want to CREATE music, or REPRODUCE music, that was already created?

Years ago, I had two Mark Levinson Class A Solid State Amps. They weighed about 160 lbs and gave off enough heat to warm a large room. But the sound was the smoothest, sweetest sound I have ever heard. Too bad I needed the money back then for a car.

Class AB Valve 100 watts RMS/channel THD :0.1 %

It would come down do you like sound of tubes or solid state in my book. So Class A Solid State or Class A Valve.

Maybe something from Lexicon would be in that league solid state wise..

There is much more to consider when choosing an amp. such as balanced or unbalanced inputs, what demand you speakers will place on it and finally what speakers. It has been my experience that some speaker and amp configurations don't play well together.

Your question is therefore ambiguous and I am unable to make a recommendation!

Assuming they are all good quality, I doubt that most people could hear any difference at all.