Tube cross-reference
6CU7 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6CU7 voltage - triode (with diode, heptode or hexode). Compare core specifications and verify every restriction before using a replacement.
Exact variations of 6CU7
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.
ECH42 Voltage - Triode (with diode, heptode or hexode)
- Base
- Not recorded
- Socket
- B8A
- Base pins
- 8
- Sections
- 2
- Heater voltage
- 6.3 V
- Heater current
- 0.23 A
Replacement tubes for 6CU7
The following tubes are recorded as possible replacements for 6CU7. This direction does not establish that 6CU7 can replace them.
Voltage - Triple Triode
The database records 6C10 as a possible replacement for6CU7.
- Parallel heater circuits only
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triple Triode |
| Construction | Hexode-Triode | Triode-Triode-Triode |
| Base | OCTAL | Not recorded |
| Socket | B9A | Not recorded |
| Base pins | 9 | 12 |
| Sections | 2 | 3 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.55 A |
Voltage Radio Detector Converter
The database records 6C9 as a possible replacement for6CU7.
- Parallel heater circuits only
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage Radio Detector Converter |
| Construction | Hexode-Triode | Tetrode-Tetrode |
| Base | OCTAL | 10F |
| Socket | B9A | B10G |
| Base pins | 9 | 10 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.4 A |
Voltage - Triode (with diode, heptode or hexode)
The database records ECH42 as a possible replacement for6CU7.
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 | Hexode-Triode |
| Base | OCTAL | Not recorded |
| Socket | B9A | B8A |
| Base pins | 9 | 8 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.23 A |
Where 6CU7 can be used as the replacement
In these recorded relationships, 6CU7 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6CU7.
Voltage - Triple Triode
The database records 6CU7 as a possible replacement for6C10.
- Parallel heater circuits only
| Specification | 6CU7 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triple Triode |
| Construction | Hexode-Triode | Triode-Triode-Triode |
| Base | OCTAL | Not recorded |
| Socket | B9A | Not recorded |
| Base pins | 9 | 12 |
| Sections | 2 | 3 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.55 A |
Voltage Radio Detector Converter
The database records 6CU7 as a possible replacement for6C9.
- Parallel heater circuits only
| Specification | 6CU7 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage Radio Detector Converter |
| Construction | Hexode-Triode | Tetrode-Tetrode |
| Base | OCTAL | 10F |
| Socket | B9A | B10G |
| Base pins | 9 | 10 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.4 A |
Voltage - Triode (with diode, heptode or hexode)
The database records 6CU7 as a possible replacement forECH42.
No special restrictions are recorded for this substitution.
| Specification | 6CU7 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (with diode, heptode or hexode) | Voltage - Triode (with diode, heptode or hexode) |
| Construction | Hexode-Triode | Hexode-Triode |
| Base | OCTAL | Not recorded |
| Socket | B9A | B8A |
| Base pins | 9 | 8 |
| Sections | 2 | 2 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.23 A | 0.23 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 6CU7 specifications →