Russian 6AS7

This is the power tube used in the Feliks Audio Elise & Euforia headphone amplifiers. Purchase is restricted to owners of those products.

Early production Russian tubes. Manufactured in the Svetlana Electron Devices (Winged "C") factory in St. Petersburg. Some are branded 6H13C, which was the Soviet military designation for 6AS7, some are marked as Svetlana or Sovtek, but they're all from the same place.