Excellent question! I've made the same observations with many tube amps vs SS over the years, both in my system and in others, and is one of the major reasons I prefer tubes. The soundstage is almost always taller, wider, deeper, and more saturated. Along with this is often a lushness and clarity to the mids and upper mids, as well as air around the treble notes that’s less obvious when I listen to SS. I can’t say as though I know the answer for this definitely, and I certainly don’t mean to turn this into a tube vs SS debate, but I have always suspected that it’s related to higher resolution of the tube amps, which simply
reveals more information and brings us closer to the events of the recording, with both direct and ambient information that contributes to the sense of space.
Tube Amp soundstage
I hope everyone is safe and healthy during these strange times. I wondering if someone could explain to me the reason my tube amp has a deeper soundstage than my SS amps? Two years back I built an Elekit 8200 which puts out around 8-10w/c in ultra linear mode, depending on the power tubes. I usually run KT88’s or 6L6’s, and less often EL34’s. It powers a pair of Tekton Enzo 2.7’s which are quite efficient at a claimed 98db. The SS amps I’ve used with these speakers include a vintage NAD 35w receiver, a Musical Fidelity m3si @ 85w, a Rogue Sphinx @ 100w and a Hegel H80. Now granted, non of these amps are what I would consider high end audio, but no matter what, the little tube amp always seems to have a deeper, more 3-D soundstage and the SS amps sound a little flatter. Same source, same DAC, same speakers and cables. There are things I appreciate about the SS sound, such as tighter, better defined bass and an effortless ability to play louder (which I do less and less), but every time I rotate the little tube amp back in, I hear a slightly more organic sound and that deeper soundstage.