Tube cross-reference
5638 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 5638 voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Exact variations of 5638
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.
SD528A NEW (being researched)
- Base
- Not recorded
- Socket
- Not recorded
- Base pins
- Not recorded
- Sections
- 1
- Heater voltage
- Not recorded
- Heater current
- Not recorded
Where 5638 can be used as the replacement
In these recorded relationships, 5638 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 5638.
Voltage Pentode - Sharp Cutoff (single)
The database records 5638 as a possible replacement for6BA5.
No special restrictions are recorded for this substitution.
| Specification | 5638 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | 5638 | Not recorded |
| Socket | SUBMINIATURE6 | B7G |
| Base pins | 6 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.3 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 5638 specifications →