Class A, A/B vs Class D amp Soundstage


Good evening. 
i just upgraded my Cambridge 850R Class A/B to Cambridge EVO 150 Class D with integrated streamer. I use B&W Diamond II with good cables and interconnects. So, there isn’t really a weak link in my system to be uncovered or exposed when going to a. Class D amp. 
There actually is nothing I changed other than the amps

I lost all front to back soundstage. I lost 50% of my right to left soundstage (speaker position has not changed at all and is 6 ft from the back wall. 
I stream hi-res from Qobuz.  The mid-range sounds a tad bit muffled. The base drivers distort and lower top power than my other amp which remained tight in the base even at ear hurting volume. 
 

The only and I mean only thing I did was change amps. So, I am wondering, does going from a class a/b to a class d amp cause a significant decrease in soundstage?  So far, whatever it is, I don’t like it at all, not one kilo-bit

128x128geworthomd

Sorry for the additional update. I can also describe it as the Class A/B sounded like I was sitting in front of the stage in a small venue. Yes, still an amplified system in that small venue and not the real guitar - unamplified sound. Now it sounds like I am listening to a hifi stereo. 
Base is definitely not as tight and more distorted. 
 

Hey, second question:  does Anyone ever listen and like a center speaker for audiophile audio (not tv). Though, I would not know how to wire it in the system. 

Is this a new or used amp?

If new, contact the seller of the Class D and ask if there is a break-in period for the amp. The sound you're describing is very similar to a component that hasn't been run-in.

Also, check to see if you wired amp and speakers in phase.