It sounds like you’re hearing the microdynamics that EC is famous for, and AF specifically strived for. And it’s definitely (if you follow @purr1n) a sonic characteristic. Check out this informative post: http://www.superbestaudiofriends.org/index.php?threads/the-audio-101-thread.3214/page-2#post-96125 EC (in my case 2A3 MK2) + Utopia is a very good pairing, both working together to deliver oodles of microdynamic and microdetail (plankton) across the frequency range. Not everyone cares/appreciates/heads this and there are no objective measurements for microdynamics (at least I’ve come accross), but for me this is so addictive I am willing to sacrifice other characteristics (such as bass quantity, even some quality) for this. IMHO the NOS RCA 2A3 tubes may be less warm and have more treble energy than new stock PSVane WE275 (haven’t tried others), but to me they have better microdynamics and plankton. I’d take that any day (and worst case slightly 1/2 dB EQ to take a little edge of treble).