Describe ube sound vs solid state

Actually there are a good number of tube amps that can do that. Any Mac for example. Ever hear of the Wolcott? Henry made a point of advertising that his amp could operate as a true voltage source.

All amps have higher distortion into lower impedances. As far as that goes, there is no argument for a 4 ohms speaker in the world of high end, not if sound quality is your goal. Why force all amps to have higher distortion??

You still need the impedance taps otherwise you may not be getting the most out of the amp.

As I read it from their own respective web sites none of the amps from either McIntosh or Wolcott can do that.

http://www.mcintoshlabs.com/us/Products/pages/ProductListingHorizontal.aspx?CatId=amplifiers

http://www.wolcottaudio.com/WA_Pres_specs.htm

I disagree with your assertion that :"...there is no argument for a 4 Ohm speaker in the world of high end,..."
Some of the most accurate loudspeakers ever made journey into and below that impedance. ...But that is probably a more appropriate discussion for another thread.

You didn't look deep enough.

From the Wolcott site:

http://www.wolcottaudio.com/WA_presence.htm:

What if we told you that our very different tube amplifier had highly accurate autobiasing, a nearly infinite damping factor, acted as a pure voltage source into almost any real world speaker load,

Well, I would respond to the Wolcott statement that the specs on their own web site contradicts that.

I don't see anything that supports your statement- perhaps you could point it out?