Tube cross-reference
0A3 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 0A3 voltage regulator. Compare core specifications and verify every restriction before using a replacement.
Exact variations of 0A3
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.
VR75 Voltage Regulator
- Base
- 4AJ
- Socket
- Not recorded
- Base pins
- 4
- Sections
- 1
- Heater voltage
- Not recorded
- Heater current
- Not recorded
Replacement tubes for 0A3
The following tubes are recorded as possible replacements for 0A3. This direction does not establish that 0A3 can replace them.
Voltage Regulator
The database records KD21 as a possible replacement for0A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Regulator | Voltage Regulator |
| Construction | VoltageRegulator | VoltageRegulator |
| Base | 4AJ | Not recorded |
| Socket | IO | Not recorded |
| Base pins | 8 | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | Not recorded |
| Heater current | Not recorded | Not recorded |
Voltage Regulator
The database records VR75 as a possible replacement for0A3.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Regulator | Voltage Regulator |
| Construction | VoltageRegulator | VoltageRegulator |
| Base | 4AJ | 4AJ |
| Socket | IO | Not recorded |
| Base pins | 8 | 4 |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | Not recorded |
| Heater current | Not recorded | Not recorded |
Where 0A3 can be used as the replacement
In these recorded relationships, 0A3 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 0A3.
Voltage Regulator
The database records 0A3 as a possible replacement forKD21.
No special restrictions are recorded for this substitution.
| Specification | 0A3 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Regulator | Voltage Regulator |
| Construction | VoltageRegulator | VoltageRegulator |
| Base | 4AJ | Not recorded |
| Socket | IO | Not recorded |
| Base pins | 8 | Not recorded |
| Sections | 1 | 1 |
| Heater voltage | Not recorded | Not recorded |
| Heater current | Not recorded | Not recorded |
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 0A3 specifications →