← Reference

5881

also 6L6WGB

The ruggedized member of the 6L6 beam-power line — Tung-Sol's premium-quality 6L6, and the output tube the tweed 5F6-A Bassman is drawn around. It shares the family's 7AC octal basing and its Class A1 characteristics with the 6L6GC, but not its ratings: 23 W on a 400 V ceiling against the 6L6GC's 30 W on 500 V. A circuit is bound to the model whose name its drawing prints, so the amps lettered 6L6GC use reference/tubes/6l6gc.yaml and only the ones lettered 5881 are here; where a drawing letters the older 6L6G, this model stands in for it (5E5-A, 5E6-A, 5F4 — documented on those entries).

Basing (pinout)

Bottom view — the socket as you see it from the wiring side. Hover, tap, or focus a pin to name it. Read from the datasheet basing diagram (how to read these →).

1 2 3 4 5 6 7 8

Hover, tap, or focus a pin to name it.

  • High voltage (B+)
  • Control grid
  • Cathode
  • Heater / filament
  • No connection

Viewed from below (socket / wiring side) · octal · basing 7AC

⚡ Oxblood pins sit at B+ — hundreds of volts in service, lethal, and still charged after power-off.

Datasheets

Primary manufacturer data, via public tube-data archives. The model below is fitted to the tabulated "average characteristics" in these sheets; the datasheet files themselves are linked, never rehosted.

PublisherTypeSource
RCA 6L6GC frank.pocnet.net ↗
General Electric 6L6GC frank.pocnet.net ↗
Tung-Sol 6L6GC frank.pocnet.net ↗
RCA 5881 frank.pocnet.net ↗
Tung-Sol 5881 frank.pocnet.net ↗

Circuit Codex model

A CC0 ngspice model in the Koren form, fitted here to the published anchor — no parameters copied from other model collections. Methodology →

Anchor
Va=250 V, Vg2=250 V, Vg1=-14 V → Ia=72 mA, Ig2=5 mA, gm=6000 µmho
Source
RCA Receiving Tube Manual RC-19, 1959, average characteristics (6L6GC)
Note
5881/6L6WGB is treated as 6L6GC-class at these ratings. µ is the grid-No.1-to-grid-No.2 amplification factor (8, RC-19).
File
models/5881.inc ↗

See these parameters drawn: the load line explorer plots the 5881's plate-curve family from this model and solves an operating point on it.

Maximum ratings

Design-center maximums for the 5881 as printed by Tung-Sol. The 5881's rugged construction trades the 6L6GC's higher ceiling for durability: it is rated below the 6L6GC on both plate dissipation and voltage (23 W / 400 V against 30 W / 500 V), which is why a 6L6GC drops into a 5881 socket with margin to spare while a 5881 run at 6L6GC voltages sits near its limit.

Plate dissipation
23 W
Plate voltage
400 V
Screen (grid No.2) voltage
400 V
Screen dissipation
3 W
Rating system
Design centre — carries an allowance for manufacturing spread
Source
Tung-Sol 5881 datasheet (design-center system) ↗