Solid state amplifiers and sound stage, especially front to back "depth"

@hilde45 - I am quite familiar with that amp as I own both it and the 120 (little brother).  Both excellent amps with great bass control and articulation.  Certainly hifi and quite a bargain at the price on offer. However, your finding is the same as mine - they present a forward sound stage with limited depth.  I've just purchased Frank Van Alstine's latest DVA M225 monoblocks - first retail customer - I posted a review on AudioCircle.  Boy howdy do these amps deliver - they have a wide and deep soundstage.  So certainly ss can do depth when well implemented.

Thanks @wjob the DVA M225 sounds like a better fit. 

At least from what I’ve read day-to-day from Paul McGowan regarding designing, and then listening, seemed to apply most to the speakers they are creating where they use the IRS Vs as their archetype sound to try to match and then build upon without simply copying Arnie Nudell’s incredible speakers (not just add modern crossovers, etc). They found that two different speakers prototypes they came up that demonstrated the same “math” on “paper” sounded distinctly different. They also found that creating a world class speaker is extremely difficult. I get the impression it is arguably the most difficult component to “master” from the ground up even when you know your specific goals. That really stuck with me. Anyway, that’s a whole new rabbit hole discussion. 
@hilde45 my compliments on your moderating. Want to do this for every top level discussion on Audiogon? You’re the antithesis of our loathed friend, who shall not be named, that thankfully got banned a few months ago. He “thought”, for instance, the best, and only speakers worth anything, would be a concrete edifice that he would somehow design with his all encompassing wisdom 😂. All he did was unleash anarchy and anger, accompanied by virtual torches and dynamite, into the population🤬🔥🧨.

@parker65310  Thanks for your post and your nice comment. I wouldn't be a moderator in anything but a classroom. There, carrots and sticks exist. Here, in the West World of audio discussion, almost anything seems to go! I'd get too many cuts and bruises.

I do feel that if I start a thread, I need to try to keep responding to comments and try to summarize where things are at, unless it just takes off in a (happy or unhappy) tangential direction. And I'm happy to back off if what becomes a side discussion takes over. I've learned a lot from these threads. There are some masterclass level teachers here with a lot of experience. It pays to listen.

My 1993 B&K EX442 Sonata (350 wpc/4 ohms) puts me right in the studio whenever I listen to "Kind of Blue".  It's pairing with my MMGs (out 3' from the wall) gives me an excellent soundstage in both width and depth.