I recently bought a 2100 brushed silver face, the seller mentioned that the amp has the original EL34s but KT88/6550s are also compatible
Can that be true?
Here is the user manual for the 2150 and the 2100 Classic
2100-2150.pdf (2.7 MB)
It seems only designed for EL34s, so I don’t think so. KT88 are quite different…
8 x 6CA7/EL34 output tubes, four per channel, 120 W per channel, 56 lbs, plus a rear Pentode/Triode MODE switch and a three-position standby (half power / off / full power) that the 2150 doesn’t have.