I'm curious. Do you guys feel that NOS really provide a much better sound? I have a bunch of tubes, but they're all current production. I could get some NOS ones but they're quite a bit more expensive. Also, have you tried any of the lower gain tubes such as 12AT7s or 12AU7? I don't have any high impedance cans and never go past the 12 O'clock mark on volume so I've been thinking that I don't really need the gain of 12AX7s.