| PIN | EM87/HU6, EM84/6FG6, EM85/6DG7/6DU6, EM840 | EM80/6BR5/6M40, EM81/6DA5 | EM71, EM72 |
| 1 | grid (triode) | grid (triode) | filament |
| 2 | - | cathode | screen |
| 3 | cathode | - | grid (indicator) |
| 4 | filament | filament | - |
| 5 | filament | filament | plate&target |
| 6 | screen | - | grid (triode) |
| 7 | target | plate&target | - |
| 8 | - | - | filament |
| 9 | plate | screen | |