SET vs Class A vs tubes vs Class AB amps

Long time reader, first time poster here. Can someone describe the basic differences in sound between a Class A amp , an SET amp, a Class AB and a regular tube amp? Are there basic sound differences in the general sense? I have only owned Class AB amps.
Lewinskih01/Horatio...on the Audio Aficionado site there are hundreds of pages devoted to all aspects of Dennis Had amps. That site can keep you busy for hours and make your head spin with the "what power tubes with what rectifier with what input tube" endless discussions. Fun stuff.
I have two amps. A 300b SET from AncientAudio and the 12R (solid state) from Bakoon. They sound more similar than different.
As mentioned by pretty much all posters above it depends on the designer how the amplifier is going to sound and its advantages or disadvantages. The ultimate goal is to power the speaker comfortable with more power in reserve than the speakers will need and not to impart a sound coloration onto the music.
The more important issue is a total system synergy where all the components work well with each other. Component matching to the size of your room, your taste in music and preferred listening volume.
I think you might find the Sanders white paper on Tubes vs. Transistors to be educational.  Look for or something like that. 
You want to seek a good sounding amp, and unless you have difficult speakers to drive, the type is irrelevant.

I have two systems with Class A, one with AB and one with tubes.