EF6

Small Signal Pentode — P8A

Philips

Known Equivalents & Substitutes

6E2S620TEF6VEF6

Similar Tubes (Not Drop-In Compatible)

American Octal equivalent by function (sharp-cutoff pentode) — similar electricals but Octal base

EF36

Electrically equivalent pentode but Octal base — not pin-compatible with P8A side-contact base

Improved version of EF36 on Octal base with lower microphony — same electrical characteristics, different base

EF40

Post-war Rimlock (B8A) replacement with similar characteristics — different base type

EF6N

Variant designation for the same tube — verify exact manufacturer/version before substituting

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)300V

Screen Voltage (max)Screen Voltage (max)150V

Anode Dissipation (max)Anode Dissipation (max)1.5W

Screen Dissipation (max)Screen Dissipation (max)0.3W

Cathode Current (max)

Notes

European side-contact base P8A (also designated Au P or 8SC) with top-cap anode connection.
Part of the Philips 1938 Miniwatt all-glass tube range using the P8A pressed-glass base construction.
Brans Vademecum lists EF6 in the same functional family as 6SJ7, EF36, EF37A, EF40, EF80, and E80F — but these are NOT pin-for-pin equivalents due to different base types.
TDSL lists 6E2, S620, TEF6, and VEF6 as close or identical substitutes.
The EF6 shares the P8A base family with other Philips tubes like EF50, EL50, and EF9 — check pin assignments before interchanging.
Muiderkring data categorises EF6 as pentode (category 'p').
Philips interchange guide (1962) lists EF6 with no recommended replacement — indicating it was considered unique in its base type.

Pin Layout — P8A

1Metallization / Screen

2Heater

3Cathode

4

References