I did. Some users on this forum liked the sound of the GT2308 and PedalHacker had one available awhile back so went with it. I really like the sound, though after dialing in the trim to my taste. I did not audition others so take it with a grain of salt. Another user here: caiofilipini compared it to his real Hudson and said that they used a 2n404A instead of the OC71. I think as long as the HFE is low on these PNP transistors, it should be usable.So did you replace the OC71 with a GT2308?