2 True NOS Rare Sealed Box Matsu/Mullard 12AU7 ECC82 Vintage Preamp AudioTubes

True nos sealed box are the crown jewels! Having not been handled in over 60+ years besides the factory workers sealing them up, pristine collectible condition pair. Literature tells us these had legendary mullard influence and tooling via'transfer of technology' licensing agreements. National tubes feature uniform noise-free characteristics, long service life, superior sound reproduction and more. Pair of 12au7 ecc82 hard vacuum japan made vintage w/ most precious tube-era metallurgy and warmth.

If opened, always give 100+ wake hours before bench test due to long term hibernation, cathodes are quite fragile. Authentic vintage hifidelity audio curation by caliacoustics.