6AK5

Small Signal Pentode — B7G

RCA

Known Equivalents & Substitutes

EF955654CV8506AK5WCK6AK56096M81006J1408APM056F32E95F6069

Similar Tubes (Not Drop-In Compatible)

5690

Same base and similar characteristics but different heater current (0.15 A vs 0.175 A)

5743

Ruggedized industrial version with tighter parameter controls and longer rated life

6AH6

Higher-gm sharp-cutoff pentode on same B7G base but different pinout and much higher plate current — not a drop-in

Electrical Specifications

Section 1 — Pentode

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)180V

Screen Voltage (max)Screen Supply Voltage (max)180V

Anode Dissipation (max)Anode Dissipation (max)1.7W

Screen Dissipation (max)Screen Dissipation (max)0.5W

Notes

Suppressor grid (g3) is internally connected to cathode.
Pin 2 (cathode) and pin 7 (cathode) are connected internally — both must be grounded for proper RF shielding.
Screen dissipation limit is 0.5 W for screen voltages up to 90 V. For screen voltages between 90 V and 180 V, see the RCA Grid-No.2 Input Rating Chart.
MIL-HDBK-213A lists 6AK5W and CK6AK5 as alternate designations. 5654/6AK5W is the reliable/ruggedized military version.
Brimar rates Vg2_max at 90 V (conservative), while RCA rates the screen supply voltage at 180 V max. The actual screen voltage depends on the application and dissipation limits.
Capacitance values without external shield: Cgp=0.03 pF max, Cin=4.0 pF, Cout=2.1 pF. With external shield: Cgp=0.02 pF max, Cout=2.8 pF (shield adds anode capacitance).
Triode-strapped data from Mullard EF95 datasheet: mu=35, gm=6.8 mA/V, ra=5200 Ohm at Va=120 V, Ia=10 mA.

Pin Layout — B7G

1Control Grid

2Cathode,Suppressor Grid (g3 internal)

3Heater

4

Socket-Compatible Tubes ⚠ Not electrically compatible

References