Electro-Harmonix 12AT7EHG Data Sheet

12AT7EH
pin # Electrode name

1 Plate of 2nd triode
2 Grid of 2nd triode
3 Cathode of 2nd triode
4,5,9 Heater
6 Plate of 1st triode
7 Grid of 1st triode
8 Cathode of 1st triode

Electrical data of new tube
Comment
Grid reverse current, µa, not more 0.5 3, 4
Heater current, ma not less 330 1
165 2
not more 360 1
180 2
Plate current, ma not less 7.0
not more 13.0
Plate current at the beginning of the
curve, µa not more
Transconductance, ma/v, not less 4.5 3, 5
Amplification factor, not less 50 3.5

Comments:

1. Plate voltage 6.3v

2. Heater voltage 12.6v

3. Heater voltage 6.3v or 12.6v

4. Plate voltage 250v, grid voltage -2v, grid circuit resistance 0,25 Mohm

5. Plate voltage 250v, grid voltage -2v

6. Plate voltage 250v, grid voltage -12v
Electrical parameters that could be changed within exploitation

Transconductance, ma/v, not less 3.5
Grid reverse current, µa, not more 0.7

Limited values
Heater voltage, v, not less 6.0 or 12.0
not more 6.6 or 13.2
Plate voltage, v, not more 330
Cathode to heater voltage:
Positive, v, not more 200
Negative, v not more 200
Plate current, ma not more 18
Plate dissipation power of each triode, W, not more 3.25
Each triode grid circuit resistance:
under fixed bias, Mohm, not more 0.25
under automatic bias, Mohm not more 1.0
Max grid reverse current, v, not more 55

The tube can’t be exploited at two or more limited conditions.

10 3, 6

3, 5

Interelectrode capacitances:

Input capacitance of each triode, pf, nominal 2.5
Output capacitance of each triode, pf, nominal 0.4
Transfer capacitance of each triode, pf, nominal 1.6