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

Room treatment.

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.

@hartf36
Mine broke beyond parts-repair, 50yr tech tried four times to repair it, oh well, sold for parts. For 20+ years I was lucky to own and listen to my former dual mono B&K EX442-0 version of your amp. Your earlier version may have been a little more sweet sounding.   I've shared with @hilde45 how musical and 3D that amp could be [at times].  It was $2,200 retail in 1990 I think it was. The magic would only kick in after the dual mono transformers got really HOT, and that's what killed it inside over time. Frank at AVA says B&K copied his designs, whatever the case, some of the lineup back then sounded really-really nice for the $. Digital, preamp-processors, and Home Theater software is what caused them to fold in the end beyond recovery. Sad.  Had they stuck to simple 2ch audio, they'd still be around I gather. The meaty little SS affordability amps that could, and sounded a bit like tube once they got nice and toasty warm.  :)  

I read many but not all responses and there is something that seems to be missing...  that is the particular component to component compatibility of the amplifier and the rest of the gear it is associated with.  To get the best result each component should work optimally with the other components in the chain.  Your pre-amp or speakers may not work best in combination with a particular SS amplifier or cables.

This can be true, and the weakest links in the chain can impact the end-to-end result. Without having different components to easily rotate in/out it can be more challenging to easily identify and where to upgrade next. Unless of course for the lucky ones who can afford to buy their top-4 components of choice and return-ship the other 3 after the are done with evaluating in batches, its another way to save time and cut to the chase faster. 

Most Audiophiles don’t realize that your amp,preamp can greatly be improved.
the parts quality on the majority of products under $10k is average at best.
I just bought the excellent Coda CSIB integrated amp .Stereo times has a excellent review ,and build quality and sound much better then average and over built by most any standard , look inside your amp ,most have a small toroidal transformer
the coda is potted for ultra low noise and 3kva 4 x the average  and over 80k 
in capacitance. That’s why I inspect every product I buy. I did upgrade the very good rel multi caps to the VH Audio Odam  caps ,in the preamp section 
that was all there was to upgrade . Coda has been in business for over 35 years 
and very much under the radar , well worth checking out ,
and a 10 year warranty.