Tube cross-reference
6AJ8 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6AJ8 voltage - triode (with diode, heptode or hexode). Compare core specifications and verify every restriction before using a replacement.
Exact variations of 6AJ8
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.
ECH81 Voltage - Triode (with diode, heptode or hexode)
- Base
- B9A
- Socket
- B9A
- Base pins
- 9
- Sections
- 2
- Heater voltage
- 6.3 V
- Heater current
- 0.3 A
Replacement tubes for 6AJ8
The following tubes are recorded as possible replacements for 6AJ8. This direction does not establish that 6AJ8 can replace them.
Voltage - Triode (with diode, heptode or hexode)
The database records 20D4 as a possible replacement for6AJ8.
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 | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 |
Voltage - Triode (with diode, heptode or hexode)
The database records 6C12 as a possible replacement for6AJ8.
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 | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 |
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 | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Heptode-Triode | Hexode-Triode |
| Base | E9-1 | B9A |
| 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 |
Voltage - Triode (with diode, heptode or hexode)
The database records X719 as a possible replacement for6AJ8.
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 | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 6AJ8 can be used as the replacement
In these recorded relationships, 6AJ8 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6AJ8.
Voltage - Triode (with diode, heptode or hexode)
The database records 6AJ8 as a possible replacement for20D4.
No special restrictions are recorded for this substitution.
| Specification | 6AJ8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 |
Voltage - Triode (with diode, heptode or hexode)
The database records 6AJ8 as a possible replacement for6C12.
No special restrictions are recorded for this substitution.
| Specification | 6AJ8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 |
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 | 6AJ8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Heptode-Triode | Hexode-Triode |
| Base | E9-1 | B9A |
| 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 |
Voltage - Triode (with diode, heptode or hexode)
The database records 6AJ8 as a possible replacement forX719.
No special restrictions are recorded for this substitution.
| Specification | 6AJ8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Heptode-Triode | Heptode-Triode |
| Base | E9-1 | Not recorded |
| 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 6AJ8 specifications →