Same mu=20 medium-mu triode but different internal design and separate cathodes — verify pinout
7AU7
Same electricals but designed for 600mA series-heater string with controlled warm-up — Noval base, pin-compatible
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)300V
Anode Dissipation (max)Anode Dissipation (max, per section)2.75W
Cathode Current (max)Cathode Current (max)20mA
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)200V
Notes
From Tung-Sol datasheet: 'Except for heater ratings and heater warm-up time, the 6AU7 is identical to the 12AU7.'
Heater: 6.3V/0.3A (series) or 3.15V/0.6A (parallel). For 12.6V operation apply heater voltage between pins 4 and 5. For 6.3V operation apply heater voltage between pin 4 and pins 5+9 connected together.
Maximum ratings (Class A1): Va_max=300V, Pa_max=2.75W per plate (5.5W both), Ik_max=20mA, Vhk_max=200V, Rg_max=2.2MΩ.