Tube cross-reference
6AX8 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6AX8 voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 6AX8
The following tubes are recorded as possible replacements for 6AX8. This direction does not establish that 6AX8 can replace them.
Voltage Radio Detector Converter
The database records 6CQ8 as a possible replacement for6AX8.
- Not suitable for all circuits
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Radio Detector Converter |
| Construction | Pentode-Triode | Tetrode-Triode |
| Base | 9AE | 9GE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Radio Detector Converter
The database records 6EA8 as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Radio Detector Converter |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | Not recorded |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Triode Pentode
The database records 6GH8 as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Triode Pentode
The database records 6GH8A as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Triode Pentode
The database records 6GJ8 as a possible replacement for6AX8.
- Not suitable for all circuits
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | Not recorded |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.6 A |
Voltage Triode Pentode
The database records 6LM8 as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Radio Detector Converter
The database records 6U8 as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Radio Detector Converter |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Radio Detector Converter
The database records 6U8A as a possible replacement for6AX8.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Radio Detector Converter |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | EIA 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Where 6AX8 can be used as the replacement
In these recorded relationships, 6AX8 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6AX8.
Voltage Triode Pentode
The database records 6AX8 as a possible replacement for6GH8.
- Parallel heater circuits only
- No-warmup series circuits only
| Specification | 6AX8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Triode Pentode
The database records 6AX8 as a possible replacement for6GH8A.
- Parallel heater circuits only
- No-warmup series circuits only
| Specification | 6AX8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 A |
Voltage Triode Pentode
The database records 6AX8 as a possible replacement for6GJ8.
- Parallel heater circuits only
| Specification | 6AX8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | Not recorded |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.6 A |
Voltage Triode Pentode
The database records 6AX8 as a possible replacement for6LM8.
No special restrictions are recorded for this substitution.
| Specification | 6AX8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Triode Pentode |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9AE | 9AE |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.45 A | 0.45 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 6AX8 specifications →