Same Loctal base and pinout but lower mu (16 vs 20) and different heater current (0.3A vs 0.6A)
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)300V
Anode Dissipation (max)Anode Dissipation (max, per section)2.5W
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)90V
Typical Operating
Anode Voltage (typical)Anode Voltage (typical)250V
Notes
The 7N7 was registered in April 1940, predating the more famous 6SN7GT. It is electrically identical to early 6SN7 versions but never received the uprated maximum ratings (Va_max, Pa_max) that later 6SN7GTA/GTB variants did.
Maximum plate voltage is 300V and maximum plate dissipation is 2.5W per section — significantly lower than later 6SN7GTB ratings (450V/5W). Use early 6SN7GT ratings when designing circuits.
The 14N7 is the 12.6V/0.3A series-string heater version. Pin functions are identical but heater wiring differs.
Sylvania rated the nominal heater voltage at 7.0V in their ratings section, though the typical operating voltage is 6.3V as with all other sources. The Sylvania heater current is listed as 0.640A vs Tung-Sol's 0.600A — a minor discrepancy between manufacturers.
Pin Layout — Loctal
1Heater
2Cathode (section 2)
3Anode (section 2)
4
Socket-Compatible Tubes ⚠ Not electrically compatible