Same pinout but very different mu (9.0 vs 2.7) and gm (37,000 vs 13,500 umhos) — not a drop-in replacement
6AS7G
Same pinout but much lower current capability (125 mA/plate vs 400 mA/plate) and lower heater current (2.5A vs 5.0A)
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Plate Voltage (max)400V
Anode Dissipation (max)Plate Dissipation per Plate (max)30W
Heater-to-Cathode Voltage (max)Heater-Cathode Voltage (max)300V
Max Grid ResistorGrid Circuit Resistance (max, cathode bias)0.5MΩ
Typical Operating
Notes
Designed primarily as a series pass tube for voltage regulators, not as an audio output tube. No load impedance or output power data is published — regulator service does not use a conventional load line.
When sections are paralleled, minimum cathode resistance per cathode shall be 27 ohms or the resistance necessary to produce 10% of the grid bias voltage, whichever is greater (Note 3 in datasheet).
Heater draws 5.0 A at 6.3 V (31.5 W) — requires a dedicated or heavy-duty heater supply. When connecting many high-drain tube heaters across a single transformer, use bus bars feeding from alternate ends (stranded pair) to individual sockets.
A grid resistor of 1,000 ohms is recommended per triode section to prevent parasitic oscillation, while remaining low enough to avoid loss of control from gas current.
The 6336B supersedes the 6336A with improved vibration resistance via ceramic spacers (replacing mica) and gold-plated strap frame grids. Electrically identical to 6336A.
The original 6336 (metal plates) has lower gm (11,000 umhos vs 13,500) and lower heater current (4.75A vs 5.0A) but is otherwise pin-compatible and functionally interchangeable in most regulator circuits.
Pin Layout — Octal
1Grid 1 (Section 2)
2Plate (Section 2)
3Cathode (Section 2)
4
Socket-Compatible Tubes ⚠ Not electrically compatible