Tube cross-reference
6688 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6688 voltage pentode. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 6688
The following tubes are recorded as possible replacements for 6688. This direction does not establish that 6688 can replace them.
Voltage Pentode
The database records E180F as a possible replacement for6688.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | Not recorded | Noval |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.3 A | 0.3 A |
Where 6688 can be used as the replacement
In these recorded relationships, 6688 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6688.
Voltage Pentode
The database records 6688 as a possible replacement forE180F.
No special restrictions are recorded for this substitution.
| Specification | 6688 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode | Voltage Pentode |
| Construction | Pentode | Pentode |
| Base | Not recorded | Noval |
| Socket | B9A | B9A |
| Base pins | 9 | 9 |
| Sections | 1 | 1 |
| 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 6688 specifications →