I think you are referring to an integrated amplifier? If it were me, I'd really look hard at:
(1) Hegel H400, which is an all in one solution: streamer, DAC, preamp, amp, 250WPC 8ohms and stable to 2ohms. Reviews have been great, and apparently worthy of the upgrade from the H390. New $7,000, used not available that I could find
(2) Hegel H600 Reference, same all in one unit, 300WPC 8ohms and stable to 2ohms. Same great reviews and definitely a step up from the H590. New $12,000, used $10,000
(3) Technics SU-R1000 R DAC, preaamp, and amplifier all in one, 150WPC 8ohms and 300WPC 4ohms