Scott Dorsey wrote:



Depends on the tube, basically. The 3-500Z is a well-implemented design,
but the 6146es still don't meet original spec. And the Chinese 6550
specifically says on the data sheet not to put more than 250V on the plate,
which effectively makes it unusable in anything designed for the 6550.
But on the other hand, the Chinese 211 and 833 tubes seem just fine.
--scott

Is this true for all the Chinese tubes? I note there are at least a
couple factories (Liuzhou, Shuguang-Samsung) and at least a few
different brands of the 6550 (ValveArt, Groove Tube). Can they all be
considered as equals?

Tnx,
Bill