Tube cross-reference
1231 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 1231 voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Exact variations of 1231
These designations belong to the same electrical variation group. Their names may differ because of international standards, manufacturing tolerances, or materials, but they are recorded as electrically equivalent—not merely substitutes.
7V7 Voltage Pentode - Sharp Cutoff (single)
- Base
- 8V
- Socket
- B8G
- Base pins
- 8
- Sections
- 1
- Heater voltage
- 6.3 V
- Heater current
- 0.45 A
Replacement tubes for 1231
The following tubes are recorded as possible replacements for 1231. This direction does not establish that 1231 can replace them.
Voltage Pentode - Sharp Cutoff (single)
The database records 7V7 as a possible replacement for1231.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | 8-V | 8V |
| Socket | Not recorded | B8G |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 7 V | 6.3 V |
| Heater current | 0.48 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 1231 specifications →