I will preface my response by saying I am not an audio engineer and do not have experience with your equipment. I will present my experience in the pursuit of sound stage as it relates to electronics. Another preface is that the speakers, room, wiring and power quality also apply. From the perspective of electronics the factors that affect sound stage are channel separation/cross-talk, noise, detail retrieval, and macro/micro-dynamic retrieval. Modern electronics have excellent channel separation. I focus on detail retrieval and micro-dynamic retrieval and its impact on soundstage when evaluating new electronics. I listen for how the equipment produces secondary harmonics and decay, leading edge reproduction, detail of the micro dynamics during decay, background noise, imaging and stage. I have a few test tracks I use. As an example, when I upgraded from my well maintained ‘97 vintage pre and power amp to my current integrated amp the improvements in these areas created a sound stage that was much improved and realistic. So you cannot generalize that your tube amp will give a better sound stage than your solid state. Your solid state may just be performing better than your tubes in the performance areas I mentioned. I believe my integrated amp performs as good if not better than most tube products I have auditioned, noting that I personally am bias to the cooler clarity of well designed solid state vs tube equipment.
