Thanks for all the advice. Following it I've ordered the Genalex KT88s from Jim McShane and can't wait for them to arrive.
BTW Jim said that there were, in fact, some reliability problems with the Genalex tubes but that they were limited to about 2% bad tubes from a single, earlier production run.
BTW Jim said that there were, in fact, some reliability problems with the Genalex tubes but that they were limited to about 2% bad tubes from a single, earlier production run.