well it's only preliminary, but seem like the maverick is not playing nice. Testing only Diana Krall, Fleetwood, and Norah Jone CDs right now, the vocal is a bit dry, Diana Krall sound like she has a cold, midrange is not very natural, maybe due to bad tube, tube not properly burned-in or both, top end a bit shrill and does not roll off very well, some plus points are the sound stage is acceptable, instrument separation is good, low-end is tight but not as well defined as I would like. Keep in mind that since this is still in the burn-in period and also I haven't roll any tube yet, things may change drammatically for the better. Also for some reasons the sound is a bit grainy, not sure if that's a problem or because of the design. Headphone gain is definitely high for Grado 325is but still very acceptable, no mod is needed, just dont turn the volume knob pass 10 o'clock. Well I'm gonna let the DAC settle in a bit more before drawing a final conclusion.
Testing equipt. Pioneer Elite CD/Lossless flac via USB -> Mav D1 -> Rotel 1070 -> B&W Dm603.