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Tube cross-reference

6681 alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the 6681 voltage - dual triode (similar). Compare core specifications and verify every restriction before using a replacement.

Replacement tubes for 6681

The following tubes are recorded as possible replacements for 6681. This direction does not establish that 6681 can replace them.

12AX7

Voltage - Dual Triode (similar)

Communications And Special Purpose Tubes

The database records 12AX7 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recorded9A
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 A
12AX7WA

Voltage - Dual Triode (similar)

Communications And Special Purpose Tubes

The database records 12AX7WA as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 A
6057

Voltage - Dual Triode (similar)

Communications And Special Purpose Tubes

The database records 6057 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V6.3 V
Heater current0.15 A0.3 A
7494

Voltage - Dual Triode (similar)

Communications And Special Purpose Tubes

The database records 7494 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 A
7729

Voltage - Dual Triode (similar)

Communications And Special Purpose Tubes

The database records 7729 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedE9-1 / 9A
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V6.3 V
Heater current0.15 A0.3 A
B339

Voltage - Dual Triode (similar)

Foreign To American

The database records B339 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 A
B759

Voltage - Dual Triode (similar)

Foreign To American

The database records B759 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNot recorded
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V6.3 V
Heater current0.15 A0.37 A
E83CC

Voltage - Dual Triode (similar)

Foreign To American

The database records E83CC as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNoval
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V6.3 V
Heater current0.15 A0.3 A
ECC83

Voltage - Dual Triode (similar)

Foreign To American

The database records ECC83 as a possible replacement for6681.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedB9A
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 A

Where 6681 can be used as the replacement

In these recorded relationships, 6681 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 6681.

E83CC

Voltage - Dual Triode (similar)

American To Foreign

The database records 6681 as a possible replacement forE83CC.

No special restrictions are recorded for this substitution.

Specification6681 replacementOriginal tube
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recordedNoval
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V6.3 V
Heater current0.15 A0.3 A
12AX7

Voltage - Dual Triode (similar)

Receiving To Industrial Tubes

The database records 6681 as a possible replacement for12AX7.

No special restrictions are recorded for this substitution.

Specification6681 replacementOriginal tube
Tube typeVoltage - Dual Triode (similar)Voltage - Dual Triode (similar)
ConstructionTriode-TriodeTriode-Triode
BaseNot recorded9A
SocketB9AB9A
Base pins99
Sections22
Heater voltage12.6 V12.6 V
Heater current0.15 A0.15 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 6681 specifications →