@jasonbourne71 +2

Mike

Why do tube amps generally have larger sound stages? maybe its a harmonic effect some amp do them well some don't.  Is it distortion effects, even/odd order effects?

clarity maybe, but I've heard some older vintage tube gear throw a huge sound stage with out great detail and clarity levels. so really doesn't hold up in my experience. 

Even though the OP used a YouTube video as an example its still a valid question that many of us have experienced when trying new gear. 

Why do some amplifiers throw a bigger soundstage than others?

@rrm Two things: lack of phase shift and aural effects having to do with the 2nd and 3rd harmonics, the latter of which can make an amp seem more detailed and spacious.

I like tube amps, particularly low-powered ones, and they do seem to present a larger soundstage than many good solid state amps.  My personal suspicion is that they do so because of some kind of phase anomaly.  I don't care if it is a kind of distortion or defect, if that is the case, it sounds good to me.  I know that transformers don't behave perfectly, particularly when it comes to phase shifting, and the amps I particularly like have a LOT of iron in them--input transformers, interstage transformers, and output transformers. 

I have very little experience of tube amps, but I do remember a wide soundstage.

However, the review I watched compared two solid state amps, both class A.

still don’t understand why one would would throw a wider soundstage than the other.