Tube cross-reference
U77 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the U77 rectifier - full wave. Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for U77
The following tubes are recorded as possible replacements for U77. This direction does not establish that U77 can replace them.
Rectifier - Full Wave
The database records 5AR4 as a possible replacement forU77.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Rectifier - Full Wave | Rectifier - Full Wave |
| Construction | Rectifier-Rectifier | Rectifier-Rectifier |
| Base | Not recorded | 5DA |
| Socket | Not recorded | IO |
| Base pins | Not recorded | 5 |
| Sections | 2 | 2 |
| Heater voltage | 5 V | 5 V |
| Heater current | 1.9 A | 1.9 A |
Where U77 can be used as the replacement
In these recorded relationships, U77 is the replacement tube. The listed original tubes are not automatically suitable as replacements for U77.
Rectifier - Full Wave
The database records U77 as a possible replacement for5AR4.
No special restrictions are recorded for this substitution.
| Specification | U77 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Full Wave | Rectifier - Full Wave |
| Construction | Rectifier-Rectifier | Rectifier-Rectifier |
| Base | Not recorded | 5DA |
| Socket | Not recorded | IO |
| Base pins | Not recorded | 5 |
| Sections | 2 | 2 |
| Heater voltage | 5 V | 5 V |
| Heater current | 1.9 A | 1.9 A |
Rectifier - Full Wave
The database records U77 as a possible replacement for5Z4.
No special restrictions are recorded for this substitution.
| Specification | U77 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Full Wave | Rectifier - Full Wave |
| Construction | Rectifier-Rectifier | Rectifier-Rectifier |
| Base | Not recorded | 5L |
| Socket | Not recorded | IO |
| Base pins | Not recorded | 4 |
| Sections | 2 | 2 |
| Heater voltage | 5 V | 5 V |
| Heater current | 1.9 A | 2 A |
Rectifier - Full Wave
The database records U77 as a possible replacement for5Z4G.
No special restrictions are recorded for this substitution.
| Specification | U77 replacement | Original tube |
|---|---|---|
| Tube type | Rectifier - Full Wave | Rectifier - Full Wave |
| Construction | Rectifier-Rectifier | Rectifier-Rectifier |
| Base | Not recorded | Not recorded |
| Socket | Not recorded | IO |
| Base pins | Not recorded | 8 |
| Sections | 2 | 2 |
| Heater voltage | 5 V | 5 V |
| Heater current | 1.9 A | 2 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 U77 specifications →