On another front, tubes are not really the key to great digital (natural, musical) sound. Having a digital pulse transformer on the DAC input or transport output, or both is important; avoiding digital filters, or filters altogether is very helpful; how the I/V conversion is performed makes a difference, and despite all the marketing hype, up and oversampling doesn't gain you a thing musically.

Yes, this lines up with the stuff I distribute, but it also lines up with what I've heard along the way and is my personal, as well as professional, opinion.