One Matched Pair (2 tubes), rare 6DJ8 ECC88 Amperex Made in Holland.
They are made in Philips Herlen tube plant, the same etched codes. Also the same codes printed on the bulbs.
Gray electrostatic shield, double stage ring getter.
Tested with 100V on anodes and -1.5V on grids: (16/17) (16/16)mA 16mA = 100%
Tested for noise and microphonics in phono preamp.
Brand: Amperex
Type: NOS Tube
Country of Manufacture: Holland
Country/Region of Manufacture: Netherlands