More AK380 CU impressions with balanced Laylas (bass dials at 11 o'clock):
Bass - excellent extension thru sub bass. I would not characterize the low end as fast and tight, but it's not loose or boomy either. It's got the punch, but a slower decay and nice reverb. Lots of textures and easy to discern the different instruments. Very natural imho. Outstanding on walking bass lines.
Mids - imaging is nicely centered and a little forward, but not too much imho. I don't hear any bleed from mid bass into the mids. I would characterize the mids as on the warm side. Nice complements to alto and soprano vocals.
Highs - nice extension and well below sibilance. no fatigue at all. Details are distinct. Overall I would say a little laid back.
Sound stage - I would not say this is an intimate, up front soundstage. To my ears, the sound is more further back and nicely balanced width and depth. Perhaps a little more depth than width.
Overall, when I think about how to describe the sound - musical, analog, organic, smooth, gentle, flow come to mind. I listen to a range of music from prog rock to classical and if I had to personally rate best genre fit to the AK380 CU, I would go with:
1) Classic Jazz (quartets, etc)
2) Acoustic (Latin jazz in particular)
3) Vocals
4) Classical
5) Classic Prog Rock
6) Modern Jazz
7) Everything else
The interesting thing that comes to mind for me is this - in the "everything else" category, I think my iPhone and AAC files to the AK XB10 bluetooth DAC is more than sufficient and I am ok with that. It just doesn't seem right to me to just play your average tracks with so-so mixing/mastering on the AK380 CU even though it can. It's like thinking I would never take selfies with a Leica camera, but when I see a special moment in time, absolutely give me a Leica with manual controls and let me enjoy the moment. Just my commentary.
Edit - The above was the impressions without EQ. Trying the Pro EQ, I hear a slightly tighter bass and a touch more forward treble.
TH900 pairing note - these are fairly easy to drive and plenty of volume at 100 while Laylas were around 75. Those familiar with TH900 know the U shaped FR and slightly recessed mids. Paired with the CU, it's a more neutral analytical sound versus Laylas. Very intimate with treble very much forward. Bass is tighter and faster, but I'm missing some sub-bass that I know the TH900 can deliver.
I am eagerly waiting for the CU amp to arrive as I think it will add a little dynamics to the Laylas. Will probably leave the TH900 paired with my CDM with possible stacking with the AK380. The idea of trimming down my equipment to one DAP, 2 phones, and 2 amps is very welcomed.