Like JamesP says, there are plenty of alternatives to the 6J1 out there, and very cheap. There's the Russian mil-spec version of the 6J1 - the 6J1P-EV. Then there is the bewildering array of western equivalents: the 6AK5 and its military brother the 6AK5W; the 5654 and its military spec version, the 5654W; another is the EF95; the 403A; the 6F32; the CV (common valve) 4010; the brilliant M8100; the list goes on and on. I've heard from those in the know that the AEG F95 is a very good tube - very well made and sweet sounding. 
If I were to suggest alternatives, try the military specs versions - 6AK5W, the 5654Ws, or the CV4010, although the latter, like the M8100, is hard to get. Any of these valves, at least technically, would be an improvement over the stock SHUGUANG 6J1s.

If I were to suggest alternatives, try the military specs versions - 6AK5W, the 5654Ws, or the CV4010, although the latter, like the M8100, is hard to get. Any of these valves, at least technically, would be an improvement over the stock SHUGUANG 6J1s.










If this is anything to go by, the 332 would also easily drive the 990s.




