Tube cross-reference
7731 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 7731 voltage triode pentode. Compare core specifications and verify every restriction before using a replacement.
Where 7731 can be used as the replacement
In these recorded relationships, 7731 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 7731.
Voltage Radio Detector Converter
The database records 7731 as a possible replacement for6U8.
No special restrictions are recorded for this substitution.
| Specification | 7731 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Triode Pentode | Voltage Radio Detector Converter |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | E9-1 / 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Verify before substituting
Matching a base or heater voltage is not enough to prove that two tubes are interchangeable. Check pin connections, heater current, maximum ratings, bias requirements, warm-up behavior, and the equipment manufacturer’s service documentation before making a substitution.
View the complete 7731 specifications →