Well I replaced the preamp tubes in my VFX5112 (GT 12AX7s) with JJs (ECC 83S). Not a huge sonic difference but an improvement just the same. Took out some of the shrillness in the top end and seems to be a bit more bass responsive. Not sure whether it's worth changing the power tubes out (GT EL34s) but I may do that in the future. I,ll keep the GTs as spares.
Tarl
Tarl
