Doc,
the Lucinda Williams is brilliant.
I would not put a tube in my Syrah or anything else without a coating of Silclear and if I were you, I would just enjoy the pre as is.
I have a box of nos tubes that work and a much bigger box of their partners that are noisy or dead.All of which cost a fortune.
I've had some real scares with tubes letting go and I've settled for a cheapo pair of Valve Arts that sound fine and don't try to kill my system.
Take Micks advice, leave well alone and just enjoy your music !!!
Simon