Preamp tubes in an SWR?

[ThrashMaster]

I have an SWR sm400s that I love. I've had it for probably 12 years or so no...and the preamp tube is finally, really, truely dead. Anybody have any experience with what sounds good in these amps? I actually get a fair amount of midrange grit out of it, which always surprises people, so something that will enhance that is what I'm really goin for.

[RickenBoogie]

Most hybrid heads with a single 12AX7 will have very little influence over the tone. ANY good replacement tube of the same type will work just fine, and the differences between brands will be insignificant overall.