Higher powered but efficient amp with the imaging of a Pass XA-25?

@chorus Bricasti M3 with streaming card (Qobuz) > Benchmark LA4 (soon to be replaced by Rogue RP-7) > Rowlands > KEFs and two Gallo TR-3D subs (via LA4). I have a couple of CD spinners too but really never use them anymore. And I have a Nuprime Stream9 feeding the Bricasti for streaming radio. I am not going back to vinyl.

@ghdprentice This is not a dedicated audio room. It is my living/dining/kitchen room. I tried a pair of maggie 1.7s but they dominated the room physically. Same with the X5s (had to be way out into the room), they did not do well at higher volumes (sweet as they were), and they had an extremely limited sweet spot - stand up and loose all HF. Actually the KEFs with subs load the room better than the X5s with subs, and their dispersion is such that I can enjoy the music virtually anywhere in the room (decidedly not the case with the X5s). The amp I tried was the XA-25, not the 30. Actually, the noise was probably clipping. The main problem I have with the Pass amps is their inefficiency. I do like their sound.

What I am trying to achieve is increased texture without hash and brightness; more robust sound (see next paragraph); phenomenal image depth. I find depth more satisfying than width, maybe because width is good as is.

Since my original post I partially solved my fullness problem, but at some cost. I was using some ribbon speaker cables that improved detail, slam, and imaging, but caused a number of other problems (false and irritating HF textures, metallic sounding HF at certain frequencies). With Soniquil speaker wires (Raven) the presentation is darker but rich, full, and detailed. What is missing by comparison to the ribbons is some slam. I also changed the ports in the KEFs to the shorter ones, though I can't say I really noticed much difference as a result. If anything maybe slightly muddy in the bass (by comparison). I might put the long ports back in. Or adjust the subs roll off down a bit.

@russ69 ​​​​​​​Your suggestions?

If you are looking for more power and the warmth and sweetness of Pass, I would suggest AVM.  They use a MOSFET output stage that is brilliant and offers the kind of textured sound you are looking for rather than the hyperdetailed cleanliness of a Class D.  

The AVM Ovation SA 6.3 will give you 225w of power and is a brilliant match for those Kefs at $10.5K.  

You can get a lot more power out of the Ovation 8.3 line and it has a tube input stage that uses ECC83s but it is much pricier with the 450w SA8.3 at $20K.

Another brilliant alternative is Bricasti but to get the power output you are looking for you would need to look at their monos which are $30K and $33K respectively. 

I am a dealer for both of these brands so I am undeniably biased but I do think they will work for you and resolve your problem.  

@verdantaudio Thank you for the suggestions. After I incorporate the RP-7 and explore its capabilities I will investigate the AVM line.

Maybe Luxman?  I’d be on the phone with Clayton Audio to see if they build a balanced version of their S100 amp.  Probably as good or better than Pass, and although it’s a Class A design there’s a high/low bias switch so you can leave the amp on without heating the house or running up your electric bill — kinda the best of both worlds. 

http://www.enjoythemusic.com/superioraudio/equipment/0314/clayton_audio_s100_power_amplifier.htm

The Plinius SA100 Mk3 operates similarly, and there’s a nice used one available at what I think is a bargain price if you’re open to used. 

https://www.usaudiomart.com/details/649797665-plinius-sa100-mkiii-class-a-ab-power-amplifier-updated-and-upgraded-recently/

Just a few other ideas to ponder FWIW. 

I agree with @ghdprentice . You are all over the map You have gone from 25wpc to 250wpc and from 97db floor standers to 85db bookshelf speakers. You are trying to fill a big room but that won't be done with bookshelf speakers. Changing amps isn't going to change that fact.

I too have a big room which is also my LR, & DR which is 15 x 32. I fill it with a 65wpc Don Sachs Kootenay and Silverline speakers with subs..Before that an ST-70 w/ 35wpc.  FWIW Don Sachs also has worked with Spatial audio and has their speakers