I've actually been told Sovtek in the past, but who knows...
I upgraded from the stock EL34's in my Invader, first to TungSol EL34B's and a year or so ago to JJ KT77's. Nice improvements...
V1 is a TungSol by the way.
Power tubes have to be Chinese. It's the same big bottle cookie cutter EL34 Shuguang makes for Ruby, TAD, Marshall, and other private label. Nothing from JJ.