Black Treasures cv181s which I believe are reasonably close to the Psvane suggest 300 hours, however, as noted by Rgs92 I noted an immediate improvement over some NOS 6sn7s I was using in my Modwright Ls100 preamp. For what it is worth, the Black Treasure KT88s were a step up over Gold Lion Reissues in my Ayon Spirit 2 integrated.
