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. 

I like CA streamers but haven’t heard their amps.  I suspect that this is more of an implementation issue.  Many megabuck audio companies such as Mark Levinson are using Class D in amps costing 5 figures and I haven’t seen a pattern of complaints such as yours.  Having said that, I would trade your amp for non Class D

I'd check the wiring between your speakers and amp - sounds like you may have wired one speaker out of phase (flipped + / -).

When I went from Marantz Reference series AB to Class D I noted quite the opposite of what you have experienced.  Either really poor implementation of a Class D amp or a defective unit.

Actually you changed two things, maybe three. The amp is new, so is the streamer and I am guessing you are using the built in DAC. Any or all of those things together could be affecting your soundstage. 

I'm glad the OP was at least specific in his Classe D amp.  Often we have something like "I switched to Class D and it was not as good..." with no mention of the actual amps used.

Even so, this is not a good test.  You should test against say, another integrated with built in streamer.   Also, check out the NAD hybrid Class D amps and let me know what you think.

Easy. Call Cambridge Audio and talk to one of their experts. I’m sure they would helpful input.

It would help if the OP described what streamer and DAC he was using before and currently.

As to his question about using a center channel for music, , I don’t see how to do this in his current setup 

@geworthomd , Welcome, welcome to the class D sht miracle (promised/touted by the advertising branches).....Now that you've learned your lesson, throw that class D garbage in the garbage can and go back to your AB..or even better yet, try some class A (could get a lil expensive), if you get a chance.

Of course, nowhere in this discussion is the general thoughts about the speaker impedance, and that this is a tiny integrated amplifier that might just be mismatched to the speakers, or that this is otherwise an entirely new device vs. the original.

We’ve simply thrown out all Class D because one very small integrated amp didn’t cut it.  Never mind that in all classes of amps, different amps have different output impedance curves so amp X may perform well with a pair of amps but amp y may not.

Before you throw out an entire class of amplifier altogether you need better control of the testing, and to use multiple examples of Class D.

Otherwise, if it was me, I’d say all Class A was crap because I heard one brand of Class A amps and it hurt my ears.

I’ve owned PS Audio class D. It was a must to leave amp on 24/7. If amp was put back in the system it could take 3 to 5 days before things sounded correct again. A/B amps would take maybe 24 and at most 48 hours and class A tube a few hours. Why class D took so long was a shocker the first time I discovered this.

I agree with Erik Squires suggestion of checking out NAD Class D amps, but Zlone also nailed it on three separate items being changed by going to the CA all-in-one. Did you consider the all-in-one offerings by Naim? My Seattle Dealer carries both the EVO models and the full line of Naim all-in-ones and steered me clear of the Cambridge offerings if I could somehow go with Naim [even if used over new for the Cambridge].

The Naim all-in-ones are not Class D, however. NAD does have all-in-one offerings with Class D.

I’m not that familiar with the Cambridge models you speak of but be careful lumping  all Class D amps together.  I own the Atma-Sphere Class D amps which I have directly compared to my Conrad Johnson Class AB amp in exactly the same system (like you did).  The CJ amp although older is no slouch, but the A-S amps are still better in soundstage and all other respects as well.

Thank you gentlemen. The reasoning is good behind your questions

1. B&W 802, 8 ohm, measured 6.7. Not changed.
2. 6 ft from the wall unchanged

3. Cambridge CNX into the Cambr 851a before. Similar streamer build in to Cambr EVO 150 second

4. The DAC’s are the ones inside each Cambr unit

5. Excellent idea on burn in. Bugger though, 4 days of 24 hours per day and no change

6. Double checked speaker wiring polarity

7. Highs on class d are fine. Mid is muffled like 1980’s technology. It isn’t distorted. Can crank it up but sounds like listening to an old K-mart as soon as plugged in. This is the mid section. Not noticed in the highs at all. They are crisp.
8. I have an older Red Rose Music, tube, no DAC inside. Plugged it in. Soundstage comes back (not such a powerful amp though. Plugged in a McIntosh 2100 that I also had (in the dust downstairs). No dac. Good soundstage. Not as good as tube Red Rose Music. Borrowed a Levinson with dac and changed to an older pre-alp using tubes. Best soundstage yet. Similar to the Red Rose but more noticeable than Red Rose bec it cranks up more and ears can hear the subtle timber. Plugged EVO 150 all-in- one back in (has dac and streamer) flat sounding. Limited power noticed in the base drivers. More power than Red Rose Music, More power than McIntosh, less power than Cambr 851a. Woofers flutter before ears bleed lol

9. Lots of people saying the switch to class d in their other set ups are flat i reached out to a manufacturer of high end tube class d with built in dac if I get the chance I will review for now I’ll keep that card close to my chest anxious to hear if it does work out Not too many class d, tube and modern dac inside

So, similar streamers by sane company. Burn in complete. Banana plugs on speaker wires. Qobuz hi res same songs. I have ideas but will wait for more replies first.