Tube cross-reference
6687 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 6687 heptode. Compare core specifications and verify every restriction before using a replacement.
Exact variations of 6687
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.
E91H Heptode
- Base
- Not recorded
- Socket
- B7G
- Base pins
- 7
- Sections
- 1
- Heater voltage
- 6.3 V
- Heater current
- 0.27 A
Replacement tubes for 6687
The following tubes are recorded as possible replacements for 6687. This direction does not establish that 6687 can replace them.
Heptode
The database records E91H as a possible replacement for6687.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Heptode | Heptode |
| Construction | Heptode | Heptode |
| Base | Not recorded | Not recorded |
| Socket | B7G | B7G |
| Base pins | Not recorded | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.27 A | 0.27 A |
Where 6687 can be used as the replacement
In these recorded relationships, 6687 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6687.
Heptode
The database records 6687 as a possible replacement forE91H.
No special restrictions are recorded for this substitution.
| Specification | 6687 replacement | Original tube |
|---|---|---|
| Tube type | Heptode | Heptode |
| Construction | Heptode | Heptode |
| Base | Not recorded | Not recorded |
| Socket | B7G | B7G |
| Base pins | Not recorded | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.27 A | 0.27 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 6687 specifications →