NOS double triode from russian production, military specs (-EV = longer life >5.000h and better mechanical stability), for preamps, similar to ECC83, but different pinout.
Compare to: ECC83/12AX7
Pinout: 1=A2, 2=g2, 3=K2, 4=H, 5=H, 6=A1, 7=g1, 8=K1 9=Ground
Typical operating values:
Filament 6,3V/0,35A, Ua=250V, Ia=2,3mA (per System), S=2,1mA/V, mu=100
Maximal operating values:
Ua=300V, Pa=0,8W (per System), Ukh=100V, Rg=1MOhm