I just bought a 93 MK3 Black Stripe with an EV that I'm currently re-tubing. For 6L6s I've acquired a matched quad set of NOS Sylvanias from 1980, and what I'm looking to do... is get into some pre amp tubes of the same quality. My amps have always been of a Fender variety, but I love the versatility of the Boogie. What I'm trying to accomplish is a variety of Fender tones (I'm also a Strat player) throughout all the channels. I've heard that by using different pre, verb, and phase inverter tubes (ATs, AXs, AUs) I could be heading in the right direction. But before I go emptying my pockets on tubes, I thought I'd post where I'm coming from... and get some opinions from some of you that may have gone this route (liked or disliked). I've also been told that this can be achieved through various settings on the amp itself - but I find this hard to believe, due to the very nature of what this amp was intended to do in the first place. I'm thinking that with various value tubes in different locations, maybe this can be realized?