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331A alternatives, equivalents, and replacements

Review exact electrical variations and directional substitutions recorded for the 331A power - triode (over 1000v 100w). Compare core specifications and verify every restriction before using a replacement.

Exact variations of 331A

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.

  • 805

    Power - Triode (over 1000V 100W)

    Base
    Not recorded
    Socket
    UX4
    Base pins
    4
    Sections
    1
    Heater voltage
    10 V
    Heater current
    3.25 A
  • VT143

    NEW (being researched)

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

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 331A specifications →