Tube cross-reference
401A alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 401A voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Exact variations of 401A
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.
5590 Voltage Pentode
- Base
- E7-1
- Socket
- B7G
- Base pins
- 7
- Sections
- 1
- Heater voltage
- 6.3 V
- Heater current
- 0.15 A
Replacement tubes for 401A
The following tubes are recorded as possible replacements for 401A. This direction does not establish that 401A can replace them.
Voltage Pentode
The database records 5590 as a possible replacement for401A.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | E7-1 | E7-1 |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.15 A |
Where 401A can be used as the replacement
In these recorded relationships, 401A is the replacement tube. The listed original tubes are not automatically suitable as replacements for 401A.
Voltage Pentode
The database records 401A as a possible replacement for5590.
No special restrictions are recorded for this substitution.
| Specification | 401A replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | E7-1 | E7-1 |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.15 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 401A specifications →