Pair NOS Tungsol 6520 Triode Power Tubes, 1960s, Matching Batch Numbers, Military Spec, Matching Balanced New Test Results,Superb, USA 1960s

Pair of very rare and hard to find NOS/New Vintage Military Spec Tungsol 6520 Triode power tubes. They have matching new balanced test results on both my calibrated Mutual Conductance tube testers. They have matching batch numbers. These were used for Military Spec or commercial critical applications. They have the incomparable vintage Tungsol Military Spec design, craftsmanship, attention to detail, fit, finish, sound quality and performance that only these vintage 6520 Triode power tubes can offer. They are highly highly regarded by OTL Tube amp audiophiles for their musicality, openness, detailed, transparent, dynamic, extension, spaciousness and natural sound. Many seasoned audiophiles prefer these to the vintage 5998/421A/6080 vintage tubes. They are ready to plug and play. The boxes are very worn and the top and bottom flaps are missing/typical. The shipping cost includes safe packing, prompt shipping, Reverbs Insurance and tracking number. Buy with confidence, see my feedback. Good Listening, SonnY :)