The Ruby 12AX7's that came stock in my Fuchs ODShave all become noisy and very microphonic. I don't have alot of play time on them either - certainly not enough to expect all of them to go. I've not been overly impressed with the tone of the Ruby 12AX7 in other amps but they worked well enough in the ODS to keep me from even considering replacing them. Well, last night the last one became unuseable and I'm fresh out of decent sounding spares due to having to replace the other three over the last few months. Time to buy some new preamp tubes. I remember reading Andy Fuchs post in a recent thread that he was diggin' the new Tung-Sol 12AX7's in his amps and so I went to a local music store and picked a pair up for V1 and V2. I noticed an improvement immediately. They are definitely brighter than the Ruby's and sound very musical. I like them alot! Not much more to say at this point as I haven't had alot of time to play with them in the amp but I thought I'd post my initial observations. Is anyone else here using them? How are you liking them?