Tube cross-reference
7581 alternatives, equivalents, and replacements
Review exact electrical variations and directional substitutions recorded for the 7581 power - beam (not sweep). Compare core specifications and verify every restriction before using a replacement.
Replacement tubes for 7581
The following tubes are recorded as possible replacements for 7581. This direction does not establish that 7581 can replace them.
Power - Beam (NOT sweep)
The database records KT66 as a possible replacement for7581.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | Not recorded |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 1.27 A |
Power - Beam (NOT sweep)
The database records KT77 as a possible replacement for7581.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | Not recorded |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 1.4 A |
Power - Beam (NOT sweep)
The database records 6L6GC as a possible replacement for7581.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581A as a possible replacement for7581.
No special restrictions are recorded for this substitution.
| Specification | Original tube | Replacement |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | Not recorded |
| Socket | IO | B9A |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Where 7581 can be used as the replacement
In these recorded relationships, 7581 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 7581.
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for5881.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | T7AC |
| Socket | IO | IO |
| Base pins | 8 | 7 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for6L6.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for6L6G.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for6L6GA.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for6L6GB.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 A |
Power - Beam (NOT sweep)
The database records 7581 as a possible replacement for6L6GC.
No special restrictions are recorded for this substitution.
| Specification | 7581 replacement | Original tube |
|---|---|---|
| Tube type | Power - Beam (NOT sweep) | Power - Beam (NOT sweep) |
| Construction | BeamPower | BeamPower |
| Base | Not recorded | 7AC |
| Socket | IO | IO |
| Base pins | 8 | 8 |
| Sections | 1 | 1 |
| Heater voltage | 6.3 V | 6.3 V |
| Heater current | 0.9 A | 0.9 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 7581 specifications →