Pair tube 6BQ5 compatible ball pentode tube made in Russia, black plate, measured value 78/72 (rejection value 50) with original box ※ pair is determined based on GM values measured with test machine TV-7 (Kojima Yosuke)
Accessories: original box
Pair tube Russian reprint model lot: 1609/1610 measured value 56/54 (rejected value 44) with original box*Pairs are judged based on gM values measured by testing machine TV-7 (Kojima Yosuke)
Accessories: original box