High res tube amps under $1.5k : TAD-60 perhaps?

I am looking for a new/used amp <$1.5k for my 18yo Merlin 3B+s (like Vandy 2's). I usually listen at very low listening levels due to hearing sensitivity issues (I tune pianos and get tinnitis easily from loud sounds). My Hafler 9500 sounds very musical and balanced on the Merlins, but a little grainy. I've tried an ONIX SP-3 - very musical, gutsy, but I found the low level resolution vague and I struggled to hear individual piano notes in a recording, for example. I previously had Quicksilver KT88 mono-blocks. The Hafler had much better resolution and PRAT across the board, from bass to treble IMHO, and still maintained musicality, esp. for a SS amp.

I am currently trying a Pass Aleph 30. The resolution is simply phenomenal - on some recordings I can easily recognize the harmonics of a Steinway piano versus a Yamaha for example, and I find it uncanny on how easy it is to follow a melody line and almost grasp the performer's intent as the music is being played. I can play the system at very low levels and have a detailed musical experience. It's just a bit weak on power though, and misses a little in the "ballsy" category on those days when I want to "crank it up a bit".

I'm intrigued by the TAD-60 and the ability to switch to triode mode (for more resolution?) and adjust the feedback (for more dynamics?). Can someone please comment on the TAD-60's tonal characteristics, especially low-level resolution abilities? Any other amp suggestions? DIY amp also a possibility. Thanks.