I'm looking for very low microphonics. I've got a Vox AC30CC which vibrates like crazy at the volumes I'm playing at. I need a couple of tough, reliable, warm-sounding ECC83s for V1 & V2. And I need volume. I've got a pair of GT 12AX7Ms in there now, but I can hear V2 starting to howl. I've got an NOS Mullard CV4024(12AT7) in V3. I don't necessarily want a real "high-gain" tube. At least I think I don't. If "gain" means "early breakup." I'm not looking for bone-crunching distortion. I need a clean-to-moderately-dirty tone -- with as much volume as I can squeeze out of this 30w amp. I'm looking at the Electro Harmonix 12AX7, which is supposed to be very low in microphonics and the JJ ECC83S (or is it 803S?). Anyway, what do you guys suggest?