Tube cross-reference
403A alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 403A voltage pentode - high frequency (single). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 403A
The following tubes are recorded as possible replacements for 403A. This direction does not establish that 403A can replace them.
Voltage Pentode - Sharp Cutoff (single)
The database records 6AK5 as a possible replacement for403A.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - High Frequency (single) | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | Not recorded | 7BD |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.175 A | 0.175 A |
Where 403A can be used as the replacement
In these recorded relationships, 403A is the replacement tube. The listed original tubes are not automatically suitable as replacements for 403A.
Voltage Pentode - Sharp Cutoff (single)
The database records 403A as a possible replacement for6AK5.
No special restrictions are recorded for this substitution.
| Specification | 403A replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - High Frequency (single) | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | Not recorded | 7BD |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.175 A | 0.175 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 403A specifications →