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
It is an EL34 compatible ball Mullard print sold in 1 bottle, but it seems to be made by RFT due to the structure. Measured value 48 (rejected value 30) with original box ※ measured values indicate GM values measured with the testing machine TV-7 (Kojima Yosuke)
Accessories: original box