if your preamp tubes aren't misbehaving (hiss, pop, noise) there's no good reason to replace them.
unless you just want to try some other flavors...and, generally, different flavors are a pretty small diff...
Yep I know Chef. Am a little like you & your experience with the WA. 12 oclock on the gain & the dirt starts & this is USUALLY where I set it- just at 12 oclock-so if I dig in I get a little tube 'harmonics', play soft & cleans up lovely!
I GENERALLY use a clean sound, but IF 'n when I need/want OD/distortion- I want it to be good!
Was just after a li'l more 'room' on the gain control B4 the dirt start in.
Besides - If I DON'T like the change I've got a Traynor YBA200 that I wouldn't mind experimenting with- as this has OLD pre tubes in it & they're Sovteks.
I tried a JJ 12AX7 outta another amp in the V1 pos in The YBA200 & I liked the difference in OD sound(I don't use a lot of OD, but on the few songs I DO use it, I like to crank it) eg. Temptations "Standing on Shakey Ground' has a lotta distorted bass kicked in towards the end, so I like to push it in this sort of aspect.
