Same base and pinout but significantly different characteristics: mu=47 vs 41, gm=6500 vs 8500 umhos, ra=7250 vs 4800 ohms, Ia=8.2 vs 18 mA at Va=150V. Designed for computer switching, not RF/audio. Pa_max=2.2W vs 2.7W.
6BK7B
Very similar electrical characteristics at Va=150V (gm=9300, ra=4600, Ia=18mA) but 6.3V heater only — no center-tap for 12.6V series operation.
Related Philips SQ double triode on Noval base but different characteristics (mu=27 vs 41, gm=2700 vs 8500 umhos, ra=10000 vs 4800 ohms) and pin 9 is internal shield rather than heater center-tap.
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)300V
Anode Dissipation (max)Anode Dissipation (max, per section)2.7W
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)90V
Typical Operating
Anode Voltage (typical)Anode Voltage150V
Notes
Heater: 6.3 V at 450 mA (parallel) or 12.6 V at 225 mA (series). Pin 9 is the heater center-tap — for 12.6 V operation, apply voltage between pins 4 and 5; for 6.3 V, connect pin 9 to pins 4 and 5 tied together.
Despite widespread marketing of the 5965 as '5965/12AV7', the two tubes have significantly different characteristics. The 5965 was designed for high-speed digital computer switching with sharp cutoff and low plate current; the 12AV7 was designed for VHF TV receivers with higher transconductance and plate current. They share the same base and heater configuration but are not interchangeable without circuit adjustment.
No substitutes are listed in the Howard W. Sams Tube Substitution Handbook No. 16 (1973) for the 12AV7.
Radiomuseum.org lists the 6829 as a successor type.
Pin Layout — Noval
1Anode (triode 1)
2Grid (triode 1)
3Cathode (triode 1)
Socket-Compatible Tubes ⚠ Not electrically compatible