I've owned some pretty good A/B's, Class A's, and Tubes. I'm a tube enthusiast so take this for what its worth.
First, I think that the best of Class A's and A/B's sound much more like each other than either sound like tubes. Not even close IMHO. That said, I think Class A's 'can' sound smoother because of the absence of switching distortion. CAN sound smoother, but they don't necessarily sound better depending on the sophistication of your other components and the resolution qualities of your speakers, or tonally more correct, including warmth/spaciousness.
About the only SS amps that I have heard/owned that I would use (if I had to) would be old Levinson ML2's or for something a tad more modern and more powerful Threshold SA1'. But thats just me. :-)
First, I think that the best of Class A's and A/B's sound much more like each other than either sound like tubes. Not even close IMHO. That said, I think Class A's 'can' sound smoother because of the absence of switching distortion. CAN sound smoother, but they don't necessarily sound better depending on the sophistication of your other components and the resolution qualities of your speakers, or tonally more correct, including warmth/spaciousness.
About the only SS amps that I have heard/owned that I would use (if I had to) would be old Levinson ML2's or for something a tad more modern and more powerful Threshold SA1'. But thats just me. :-)