I have found that most equipment I've bought sounds best with its stock tubes (e.g., widely known that my VAC 300.1a amp is tuned by Kevin Hayes to sound best with new tubes he provides). But with my Modwright modified Sony XA5400es, I've found that the best tubes are different than what came stock. In the power supply, a NOS Mullard GZ34 5ar4 sounds best. And by a wide margin, a matched pair of Sophia Electric 6sn7 tubes in the transport sound spectacular -- they have sounded great from day one and have given me no issues. Makes listening to SACDs and CDs on par with my expensive vinyl rig on most recordings. No digital front-end completely captures the warmth and organic presence of vinyl, but the Modwright - Sophia Electric combo is pretty darn special. And, I just engaged with Sophia Electric many months after the fact related to two more pairs of tubes, and they responded perfectly, even tho I was pretty demanding they kept their cool. If I go to replace other tubes in my system, I'm going to gravitate toward Sophia.

Darrin