Tube cross-reference
L77 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the L77 voltage - triode (single). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for L77
The following tubes are recorded as possible replacements for L77. This direction does not establish that L77 can replace them.
Power - Triode Single (under 10W)
The database records 6C4 as a possible replacement forL77.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage - Triode (single) | Power - Triode Single (under 10W) |
| Construction | Triode | Triode |
| Base | B7G | 6BG |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.15 A |
Where L77 can be used as the replacement
In these recorded relationships, L77 is the replacement tube. The listed original tubes are not automatically suitable as replacements for L77.
Voltage - Triode (single)
The database records L77 as a possible replacement for6100.
No special restrictions are recorded for this substitution.
| Specification | L77 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (single) | Voltage - Triode (single) |
| Construction | Triode | Triode |
| Base | B7G | Not recorded |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.15 A |
Voltage - Triode (single high frequency)
The database records L77 as a possible replacement for6135.
No special restrictions are recorded for this substitution.
| Specification | L77 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (single) | Voltage - Triode (single high frequency) |
| Construction | Triode | Triode |
| Base | B7G | 6BG |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.175 A |
Power - Triode Single (under 10W)
The database records L77 as a possible replacement for6C4.
No special restrictions are recorded for this substitution.
| Specification | L77 replacement | Original tube |
|---|---|---|
| Tube type | Voltage - Triode (single) | Power - Triode Single (under 10W) |
| Construction | Triode | Triode |
| Base | B7G | 6BG |
| Socket | B7G | B7G |
| Base pins | 7 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.15 A | 0.15 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 L77 specifications →