Been spending some lost time with the SR1a after having been absorbed in the 1266 TC and Diana Phi over the past several months. It had been a while and, I have to say, the SR1a remains as amazing as I had remembered it when I first heard it back in February or so. The clarity and imaging are just so on a rarefied level of its own. Nothing else really compares. Not saying that makes it "better" than other HPs I have heard or own, just that when it comes to clarity, imaging and its very unique soundstage (not necessarily bigger, wider or taller or whatever than other HPs), the SR1a just has something that is so unique and unbelievably good.
The bass is awesome - not the best for bass-heavy music like hip-hop or EDM but I don't listen to those genres anyway. For classical, classic jazz and acoustic/vocals which I listen to over 90% of the time, the SR1a - to me - is in a league of its own. But even for modern pop with a good amount of bass, the SR1a shines. I listened through Tori Amos' 'Native Invaders' (2017) album all the way through with the SR1a a few days ago and I was mesmerized - deep and big bass without any distortion at all.
Was it "better" than listening through the 1266 TC and the TToby speaker amp driving it? No, not better, just different but revealing new details that I hadn't heard before. The SR1a reveals hidden details and nuances with such clarity that it's startling. And when it comes to orchestral works, it's like: forget about it. I feel like I'm sitting right over the orchestra as in the attached photo of the LA Philharmonic performing Wagner's works last year right before the pandemic swept over the country. I can hear the individual string sections and, sometimes, even the individual instruments. That's what the SR1a can do.