Now I am skeptical of valve rollers - most of the time I can't hear much of a difference but I scored a couple of NOS 1963 GE 12AX7s on ebay at a moderately good price. WOW - I bought a box of =C= 12AX7s a while back, and liked these but the 60s GEs put in my Vibroverb at V1 and the PI has noticeably increased the presence and authority that the amp kicks out.
Trouble is, now I want some more for my other amps....
