A Line 1 isn't going to add a great deal of warmth. Even with NOS tubes mine is still pretty neutral sounding. I have no knowledge of the BAT, but will suggest adding Audible Illusions and Cary to your review list if "warmth" is the goal.
BAT or Sonic Frontiers w/ Martin Logans?
OK, I need to "warm up" my Martin Logan SL-3's with a tube amp for under $1500 (Driven by Sunfire amp). The two finalists are the BAT VK 3i and the Sonic Frontiers Line 1. Can anyone make recomendations one way or another? If any Martin Logan owners can share experiences I would appreciate it. I live over an hour away from any hi-fi stores so your input will save me lots of time.