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

Whoa! Slow down. The description of the sound you gave comes from a synergy of AMT drivers with a nice natural amp like a Pass XA30. If you want that sound you are not going to get it from some KEF bookshelf speakers and the quick choice of a high powered amp. Choice of components trying to achieve a particular goal takes a lot of work and patience.

The Pass amp you had is not noisy… period. If it sounded that way then it was probably an upstream component. Also, you are not going to fill a huge room with bookshelf speakers.

I recommend stopping for a while, taking stock of where you are and where you want to go.  the Pass XA30 is an exceptional amp. You could consider a XA60. But for speakers you either want substantial sized floor standers with an AMT driver, or Maggie’s, Matin Logan speaker or some othe planar speaker. The latter two will require an amp like a Pass x350.8. But it is not going to be as warm as the XA. I chased this dream for nearly 30 years. If you have a $100K to drop, it is pretty easy to solve… I assume you don’t.

I am happy to help, but recognize an amp purchase is not going to get you where you want to go. You need a strategy… and honestly your current strategy is going in multiple directions. If you want to talk off line give me a holler. You can see my current systems by clicking on my ID.

I am happy to help, but recognize an amp purchase is not going to get you where you want to go. You need a strategy… and honestly your current strategy is going in multiple directions.

Pretty much this, you are looking at the wrong component.

...I had an XA-25 for a trial driving a pair of Spatial X5’s (97db efficiency). That combo produced imaging depth like I have never heard before or since.

You already answered your own question here I'm afraid.  

Did you tell us the source you use?

@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?