← Reference

EZ81

also 6CA4 · 6CA4 (US equivalent)

Philips/Mullard indirectly-heated full-wave rectifier in a noval bottle — the rectifier of the Vox AC15 and of the AC30 line beside it. Rated 150 mA DC, it suits the modest current a pair of EL84s draws and, being indirectly heated, it warms up with the rest of the amplifier rather than slamming the rail up ahead of them.

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 9

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

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

Viewed from below (socket / wiring side) · noval 9-pin (B9A) · basing 9M

⚡ 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
Philips / Mullard EZ81 frank.pocnet.net ↗
RCA 6CA4 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=10 V → Ia=60 mA per anode (read from the published Ia–Va anode characteristic)
Source
Philips EZ81 data sheet, January 1970 (Double Anode Rectifying Tube), anode characteristic fig. 7Z00030-5.26.ha
Note
Child's-law diode (I = PERV·V^1.5); one anode unit, instantiate twice. The anchor is READ FROM A GRAPH, not from a table — unusually for this corpus, and stated plainly because METHODOLOGY.md treats graph reads as weaker evidence than tabulated points. The sheet publishes no per-anode voltage drop at all, only whole-rectifier system rows (transformer volts in against DC volts out, for stated filter and protecting resistances), so there is no tabulated alternative. The point above is taken from the solid, measured part of the curve, below the dashed extrapolated portion.
File
models/ez81.inc ↗