Tube cross-reference
6CU8 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6CU8 voltage pentode - sharp cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Where 6CU8 can be used as the replacement
In these recorded relationships, 6CU8 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6CU8.
6CH8
Receiving TubesVoltage Pentode - Sharp Cutoff (single)
The database records 6CU8 as a possible replacement for6CH8.
- Not suitable for all circuits
| Specification | 6CU8 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Sharp Cutoff (single) | Voltage Pentode - Sharp Cutoff (single) |
| Construction | Pentode-Triode | Pentode-Triode |
| Base | 9DX | 9FT |
| 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 6CU8 specifications →