The Gold Lions, Mullards, EH and some other brand name new production tubes are made by New Sensor in the factory in St. Petersburg that used to, and still does, make Sovtek tubes.
I don't know what differences there are between the various brands coming out of this factory. I know that the Gold Lion KT88s are considered very good tubes.
I don't know what differences there are between the various brands coming out of this factory. I know that the Gold Lion KT88s are considered very good tubes.