Special-quality long-life version of ECC82 with tighter tolerances; Va_max=330V, Pa_max=3W — pin-compatible but not an exact equivalent due to different ratings
ECC81
Same Noval dual triode pinout but higher mu (mu=60); lower plate current, higher ra — European designation for 12AT7
ECC83
Same Noval dual triode pinout but high-mu (mu=100); much lower plate current, used as voltage amplifier — European designation for 12AX7
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Max Anode Voltage300V
Peak Anode Voltage (max)Peak Anode Voltage (max)550V
Philips/Mullard designation for the 12AU7 family, introduced in 1954. Electrically identical to the American 12AU7 but specified per Philips conventions.
Philips Rg_max is 1 MΩ (cathode bias), more conservative than the American 12AU7 spec of 2.2 MΩ. Circuit designers should use the Philips limit for reliability.
Philips specifies Vhk_max = 180V vs the American 12AU7 rating of 200V. Use the more conservative Philips figure.
At Va=100V, Vg=0V operating point: Ia=11.8mA, gm=3.1mA/V, mu=19.5, ra=6250 Ohm — useful for low-voltage designs.
With Vf applied to pins 4+5 and pin 9 center tap grounded, the section on pins 6, 7, 8 has lower hum pickup.
Can be operated with 6.3V or 12.6V heater supply. Series operation at 12.6V requires a current-limiting device in the heater circuit during switch-on.
The B329 is the Philips Miniwatt commercial designation for the same tube.
Pin Layout — Noval
1Anode 2 (Triode section 2)
2Control Grid 2 (Triode section 2)
3
Socket-Compatible Tubes ⚠ Not electrically compatible