(!!!) (Best Single) E80CF=7643 Valvo branded Amperex Germany PQ NOS 1961 (Premium 6BL8 SUB) (Highest mA and Gm)

E80CF=7643 Amperex Germany PQ NOS made by Valvo Hamburg Germany 1961 (Triode/Pentode)

12.4ma Gm=5000 (triode)

14.2ma Gm=7300 (pentode)

Good Triode section Ma and Gm = 12-13ma Gm= 4500-5000

Good Pentode section Ma and Gm = 9-11ma Gm = 6000-6500

(The E80CF is a "SPECIAL QUALITY" medium-mu triode/pentode. Specs are similar to 6BL8=ECF80)

- McIntosh MR-67 tuner