Tube cross-reference
5661 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 5661 voltage pentode - remote cutoff (single). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 5661
The following tubes are recorded as possible replacements for 5661. This direction does not establish that 5661 can replace them.
Voltage Pentode - Remote Cutoff (single)
The database records 12SK7 as a possible replacement for5661.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Voltage Pentode - Remote Cutoff (single) | Voltage Pentode - Remote Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | Not recorded | 8N |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 12.6 V | 12.6 V |
| Heater current | 0.15 A | 0.15 A |
Where 5661 can be used as the replacement
In these recorded relationships, 5661 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 5661.
Voltage Pentode - Remote Cutoff (single)
The database records 5661 as a possible replacement for12SK7.
No special restrictions are recorded for this substitution.
| Specification | 5661 replacement | Original tube |
|---|---|---|
| Tube type | Voltage Pentode - Remote Cutoff (single) | Voltage Pentode - Remote Cutoff (single) |
| Construction | Pentode | Pentode |
| Base | Not recorded | 8N |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 12.6 V | 12.6 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 5661 specifications →