Tube cross-reference
ECH81 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the ECH81 voltage - triode (with diode, heptode or hexode). Compare core specifications and verify every restriction before using a replacement.
Exact variations of ECH81
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.
6AJ8 Voltage - Triode (with diode, heptode or hexode)
- Base
- E9-1
- Socket
- B9A
- Base pins
- 9
- Sections
- 2
- Heater voltage
- 6.3 V
- Heater current
- 0.3 A
Replacement tubes for ECH81
The following tubes are recorded as possible replacements for ECH81. This direction does not establish that ECH81 can replace them.
Voltage - Triode (with diode, heptode or hexode)
The database records 6AJ8 as a possible replacement forECH81.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Hexode-Triode | Heptode-Triode |
| Base | B9A | E9-1 |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.3 A | 0.3 A |
Where ECH81 can be used as the replacement
In these recorded relationships, ECH81 is the replacement tube. The listed original tubes are not automatically suitable as replacements for ECH81.
Voltage - Triode (with diode, heptode or hexode)
The database records ECH81 as a possible replacement for6AJ8.
No special restrictions are recorded for this substitution.
| Specification | ECH81 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Hexode-Triode | Heptode-Triode |
| Base | B9A | E9-1 |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.3 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 ECH81 specifications →