Based on my experience, I would recommend you audition Rogue Audio's Tempest II. I went from Simaudio's i-3 to Rogue separates, the Perseus and the Stereo 90.
I found the Rogue combo added more texture and dimension to the music while being "more neutral" than the very few other tube amplifiers I listened to in the <$1500 dollar range (used).
I found the Rogue combo added more texture and dimension to the music while being "more neutral" than the very few other tube amplifiers I listened to in the <$1500 dollar range (used).