EZ81

Rectifier — Noval

Known Equivalents & Substitutes

6CA4CV5072U709UU12

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Max AC Voltage per Anode (RMS)350V

Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)500V

Rectifier

Peak Inverse VoltagePeak Inverse Voltage1,300V

Voltage Drop (typical)Voltage Drop (typical, per plate)20V

Max C-input Filter CapacitorMax C-input Filter Capacitor50µF

DC Output Current (max)DC Output Current (max)150mA

Peak Anode Current (surge)Peak Anode Current (surge)

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current1A

Notes

A minimum series resistance per anode of approximately 230 ohm is mandatory with capacitor-input filters to limit surge current when charging the input capacitor.
Some manufacturers label pins 2, 6, 8, and 9 as internal connections (IC) rather than no connection (NC). Check the specific manufacturer's datasheet before grounding or connecting these pins.
The EZ80 (6V4) is pin-compatible but rated at only 90 mA with a 0.6 A heater — not a drop-in replacement for the EZ81 in circuits drawing over 90 mA.
Voltage drop of approximately 20 V is sourced from community measurements and forum discussions, not from the manufacturer datasheet.

Pin Layout — Noval

1Anode 1

2No Connection

3Cathode

References