I have a JOR with KT 90 tubes and absolutely love it. Recently I changed out the KT 90's to try a quad of new JJ Electronic KT 88 (blue) tubes. The sound quality was markedly lowered. I don't have a manual and since I don't see any obviously visible bias adjustment screws on the chassie I assume that the JOR is auto biasing. Or is my assumption thats it can use KT 88's incorrect. The JJ tubes were new and I only tried them for a few hours but heard no improvement with time. Do they need a longer breakin time? Any help from you or others would be appreciated.
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