Skip to main content

Tube cross-reference

KT66 alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the KT66 power - beam (not sweep). Compare core specifications and verify every restriction before using a replacement.

Replacement tubes for KT66

The following tubes are recorded as possible replacements for KT66. This direction does not establish that KT66 can replace them.

6L6GC

Power - Beam (NOT sweep)

American To Foreign

The database records 6L6GC as a possible replacement forKT66.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recorded7AC
SocketIOIO
Base pins88
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 A

Where KT66 can be used as the replacement

In these recorded relationships, KT66 is the replacement tube. The listed original tubes are not automatically suitable as replacements for KT66.

5881

Power - Beam (NOT sweep)

Foreign To American

The database records KT66 as a possible replacement for5881.

No special restrictions are recorded for this substitution.

SpecificationKT66 replacementOriginal tube
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recordedT7AC
SocketIOIO
Base pins87
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 A
5932

Power - Beam (NOT sweep)

Foreign To American

The database records KT66 as a possible replacement for5932.

No special restrictions are recorded for this substitution.

SpecificationKT66 replacementOriginal tube
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recorded7AC
SocketIOIO
Base pins87
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 A
6L6GC

Power - Beam (NOT sweep)

Foreign To American

The database records KT66 as a possible replacement for6L6GC.

No special restrictions are recorded for this substitution.

SpecificationKT66 replacementOriginal tube
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recorded7AC
SocketIOIO
Base pins88
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 A
7027

Power - Beam (NOT sweep)

Foreign To American

The database records KT66 as a possible replacement for7027.

No special restrictions are recorded for this substitution.

SpecificationKT66 replacementOriginal tube
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recorded7AC
SocketIOIO
Base pins88
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 A
7581

Power - Beam (NOT sweep)

Foreign To American

The database records KT66 as a possible replacement for7581.

No special restrictions are recorded for this substitution.

SpecificationKT66 replacementOriginal tube
Tube typePower - Beam (NOT sweep)Power - Beam (NOT sweep)
ConstructionBeamPowerBeamPower
BaseNot recordedNot recorded
SocketIOIO
Base pins88
Sections11
Heater voltage6.3 V6.3 V
Heater current1.27 A0.9 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 KT66 specifications →