I'm sure that by far the biggest factor is you're so used to the grainy etched thin hyper sound of SS and digital, and with probably just about everyone around telling you this is neutral, that its tubes that are euphonic and colored, that in your mind tubes are missing something. I can assure you the instruments are all there. At some level the gear really does become more revealing, but you're not there. You're in the realm where its all there just with a different balance. I would bet money you go back and listen and sure enough its all there, just not as in your face with tubes as with SS.
Tube and solid state, analog and digital, they're all trying to get to the same place. Painting in very broad strokes, the general trend is SS and digital over emphasize the edges, tubes and analog overdo the body. The more budget the gear the greater the tendency for this to ring true. Budget SS is nothing but etched edges. Budget tube gear smooths over details. As you climb the performance ladder this general trend stays true but the differences between the very best get closer and closer. High end SS can sound pretty damn good. But high end tubes are to die for.
What you are hearing is that contrast. Right now, and for some time to come, all your improvements to your SS gear will move it towards the warmer smoother sound of your tube amp. All your tube amp improvements will improve detail resolution closing the gap in that area with digital.
Once you start paying attention to this difference you may notice the sins of the tube amp are sins of omission. There's less of certain things. Details smoothed over, frequency extremes rolled off. The sins of solid state are sins of commission- etch and grain added, a tipped-up top end. Sins of omission are inherently less fatiguing and easier to live with than sins of commission. In part because the mind is very good at imagining and filling in what is missing, but very bad at filtering out and ignoring. SS is in your face. Tubes draw you in. Listen and see if you don't start to get what I'm talking about.
Tube and solid state, analog and digital, they're all trying to get to the same place. Painting in very broad strokes, the general trend is SS and digital over emphasize the edges, tubes and analog overdo the body. The more budget the gear the greater the tendency for this to ring true. Budget SS is nothing but etched edges. Budget tube gear smooths over details. As you climb the performance ladder this general trend stays true but the differences between the very best get closer and closer. High end SS can sound pretty damn good. But high end tubes are to die for.
What you are hearing is that contrast. Right now, and for some time to come, all your improvements to your SS gear will move it towards the warmer smoother sound of your tube amp. All your tube amp improvements will improve detail resolution closing the gap in that area with digital.
Once you start paying attention to this difference you may notice the sins of the tube amp are sins of omission. There's less of certain things. Details smoothed over, frequency extremes rolled off. The sins of solid state are sins of commission- etch and grain added, a tipped-up top end. Sins of omission are inherently less fatiguing and easier to live with than sins of commission. In part because the mind is very good at imagining and filling in what is missing, but very bad at filtering out and ignoring. SS is in your face. Tubes draw you in. Listen and see if you don't start to get what I'm talking about.