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Tube cross-reference

27 alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the 27 voltage - triode (single). Compare core specifications and verify every restriction before using a replacement.

Exact variations of 27

These designations belong to the same electrical variation group. Their names may differ because of international standards, manufacturing tolerances, or materials, but they are recorded as electrically equivalent—not merely substitutes.

  • VT29

    NEW (being researched)

    Base
    Not recorded
    Socket
    Not recorded
    Base pins
    Not recorded
    Sections
    1
    Heater voltage
    Not recorded
    Heater current
    Not recorded

Replacement tubes for 27

The following tubes are recorded as possible replacements for 27. This direction does not establish that 27 can replace them.

56

Voltage - Triode (single)

Receiving Tubes

The database records 56 as a possible replacement for27.

No special restrictions are recorded for this substitution.

SpecificationOriginal tubeReplacement
Tube typeVoltage - Triode (single)Voltage - Triode (single)
ConstructionTriodeTriode
Base5A5A
SocketUX5UX5
Base pins55
Sections11
Heater voltage2.5 V2.5 V
Heater current1.75 A1 A

Where 27 can be used as the replacement

In these recorded relationships, 27 is the replacement tube. The listed original tubes are not automatically suitable as replacements for 27.

56

Voltage - Triode (single)

Receiving Tubes

The database records 27 as a possible replacement for56.

No special restrictions are recorded for this substitution.

Specification27 replacementOriginal tube
Tube typeVoltage - Triode (single)Voltage - Triode (single)
ConstructionTriodeTriode
Base5A5A
SocketUX5UX5
Base pins55
Sections11
Heater voltage2.5 V2.5 V
Heater current1.75 A1 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 27 specifications →