12AX7/ECC83

                MAXIMUM RATINGS (Each Section)

                    Design Center Values

Zero Signal Plate Voltage                     550 volts
Plate Voltage                                 300 volts
Plate Dissipation                             1.0 watt
Cathode Current                                 8 mA
Grid Voltage                                  -50 volts
Grid Voltage (Grid current = + 0.3 uA)       -1.3 Volts
Grid Resistance[4]                              2 megohms
Heater to Cathode Voltage                     l80 volts
Heater to Cathode Resistance               20,000 ohms
Heater to Cathode Resistance[5]           150,000 ohms


                  Typical Operating Conditions

                 Class A Amplifier (Each Section)

Plate Voltage                        100       250 Volts
Grid Voltage                        -1.0      -2.0 Volts
Amplification Factor                 100       100
Plate Resistance (approx.)        80,000    62,500 ohms
Transconductance                    1250      1600 micromhos
Plate Current                        0.5       1.2 mA




Notes:
[4] With self bias.
[5] In phase-inverting circuits.