(!!!) (Best Pair) EC92=6AB4 Siemens Halske Germany branded Mullard NOS 1964 (10.2ma and 10.6ma)

1 pair) EC92=6AB4 Siemens Halske Germany branded Mullard NOS 1964

1 tube) 10.2ma Gm=5400

1 tube) 10.6ma Gm=5700

Vplate=250V

Vgrid=-2V

Good Ma range 7.5-10ma

Good Gm 5000-6000

(low noise, balanced, nice detail and extension)