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

Regarding an amp or any other electronic gear upstream’s relative ability to do imaging, it’s generally about achieving low distortion and detail retrieval. That is needed to best deliver the spatial cues that enable imaging captured in a recording completely. Then how the recording is made is the other in big factor.
Then of course the speakers setup and room acoustics determine exactly how those cues are rendered and imaging and soundstage actually produced.
The best soundstage depth Ive ever heard by a huge margin was an all mbl system with SS amplification set up in a highly customized showroom. With master recording R2R as a source you could easily identify exact location of individual orchestra instruments both front to back and side to side in a large tapered rectangular area. That was at now defunct United Home Audio in Annapolis Junction, MD several years back. Nothing else I’ve ever heard comes close on regards to precise 3-d soundstage and imaging depth. Totally holographic. Same setup by same vendor was just OK at local shows in more conventional and less optimized room setups.

In my system, holographic soundstage and imaging took a big leap forward when I introduced the Bel Canto ref1000m Class D amps to my Ohm Walsh speakers. It was totally disorienting at first until my ears latched on to what was happening. Night and day from prior Class A Musical Fidelity SS amp.

Regarding an amp or any other electronic gear upstream’s relative ability to do imaging,  it’s generally about achieving low distortion and detail retrieval. That is needed to best deliver the spatial cues that enable imaging captured in a recording completely.  
Then of course the speakers setup and room acoustics determine exactly how those cues are rendered and imaging and soundstage actually produced.

That makes sense the files in the above link I posted are to test the imaging of your system. 

Totally holographic. Same setup by same vendor was just OK at local shows in more conventional and less optimized room setups.

Very interesting post mapman...

For sure it takes a very good amplifier first but like you said and i said,  ACOUSTIC is important on the same level at least...

Are the SS amps fully burned in? I find that a 600 -800 hour burn in helps bring out subtle details in imaging.

The other thing I'm thinking is resonance and vibration.  Tube amps are more resistant to this factor.  So if not already used, good isolation devices will help.  The best in my experience are those from critical mass systems, which will take your audio to a whole new level. 

Best wishes

Skimming through other’s input I think there is another aspect that hasn’t been touched upon and that is the source recording quality. I’ve got a BAT VK-600 heavy duty solid state amp coupled with the BAT VK-5i tube amp with my Apogee ribbon speakers and I’ve found that more often than not recordings have excellent left to right, but truly great imaging that also have deep front to back complex spacing require a top quality recording engineer using the right equipment (particularly analog) and this is much rarer. This is particularly a challenge with rock recording roughly around the 80’s era. Once I hear really excellent dynamic recordings such as, for example, many of Jan Garbarek’s (ECM generally as well), Radiohead - King of Limbs, Trifonic - Emergence, just to name a few, I don’t soon forget them and I find myself returning to them like sirens as the years pass!