What is the 816 vacuum tube?

The 816 is a rectifier vacuum tube designed for rectifier applications. Mercury vapor half-wave. Blue glow magic..

What is a 816 substitute or equivalent?

Direct equivalents to the 816 include VT-216. These share the same pinout and operating envelope, so they can usually be swapped without circuit changes — though batch-to-batch variations between manufacturers (NOS vs current production) may shift the sonic character noticeably.

Is the 816 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 816 as Sought-after availability. NOS (new-old-stock) examples from RCA, Mullard, Tung-Sol, GE, Sylvania and Telefunken trade among collectors; modern production where it exists comes mostly from JJ Electronic, Electro-Harmonix, Tung-Sol (New Sensor), Genalex, and a handful of small-batch makers.

What does the 816 sound like?

Mercury vapor half-wave. Blue glow magic.. Sonic character also depends heavily on the circuit operating point, the surrounding tubes in the stage, and the output transformer when present — use the interactive loadline calculator on this page to explore the trade-offs.

By Jean-Michel Falligan Devergne · Reviewed May 29, 2026

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816 Rectifier Vacuum Tube

Rectifier2.5V / 2AUX-4

Sourcecap audit 2026-05-09Reviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Full-wave rectifier for vacuum tube power supply designs

Datasheet ↗

816 — RCA·Sylvania — rectifier vacuum tube — (1936)

GAIN0%

POWER0%

DRIVE50%

LINEARITY75%

SPECIFICATIONS

Heater2.5 V · 2 A

Max Plate Voltage1500 V

Pa max—

Gain Factor—

gm—

rp—

PinoutUX-4

Era1936

RaritySought-after

HEATER2.5V / 2A

MAX PLATE1500V

BASEux4

Source datasheets

1 manufacturer datasheets cross-checked for 816

1 verified

EXECUTIVE SUMMARY

The 816 is a directly-heated rectifier from RCA·Sylvania, introduced around 1936. Commonly used in rectifier applications. Mercury vapor half-wave. Blue glow magic.

APPLICATIONS

Power supply rectification

Generic rectifier rectifier stage

HISTORY

Introduced1936ManufacturerRCA·Sylvania

Pre-War

816 Datasheet

Local mirror · PDF

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METRIX TESTER

Test this tube on a Metrix

SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.

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