That's not really what I meant. The TH900's have their own unique sound and sense of presence with low impedance "analytical" amps, the likes of which you don't seem to have right now. I don't have a Phonitor, but given my experience with the HD800 in other setups, I can safely say the TH900 with a more SS sounding amp (again, low impedance) sounds nothing like Phonitor -> HD800. Basically the TH900's already supply all the warmth you need so you want to give them something that really takes advantage of their superb decay.
@Trogdor: yeah, the conductor's closer to what I'm describing there ^, but with some extra low end. I could actually imagine some wanting to EQ it down a bit, but the quality of said bass is still pretty great regardless so it would sound fine after doing so. I personally have no issue with it as-is, though.
Edited by driver 8 - 12/11/12 at 6:19pm