GE NOS 5R4GYA Full-Wave Rectifier Tube — General Electric, Uninstalled

CONDITION & WHAT'S INCLUDED

This is a genuine New-Old-Stock (NOS) GE 5R4GYA rectifier tube sourced from Antique Electronic Supply — a trusted NOS tube retailer. I bought it NOS and it was never installed; it simply didn't fit my amp, so it's moving on to someone who can use it.

The tube has not been used in any circuit. No test data is available — I have not run it on a tube tester — but it is unissued NOS stock. Original packaging is not noted as included; please message with any questions before purchasing.

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ABOUT THE 5R4GYA

The GE 5R4GYA is a New-Old-Stock, directly heated, full-wave vacuum rectifier tube manufactured by General Electric to military-grade specifications. It is the ruggedized variant of the 5R4GY family, originally designed for high-reliability applications in U.S. Armed Forces equipment and demanding commercial hardware.

Constructed with thick black plates, a side-D getter, and a durable brown Micanol/phenolic insulating base, the 5R4GYA is built to outlast standard commercial rectifiers. It uses an 8-pin International Octal (K8A) base and a tubular T12 straight-sided glass envelope — a classic, robust form factor sought after by audiophiles and vintage amp restorers alike.

Key electrical specifications include a 5.0V filament at 2.0A, maximum AC plate voltage of 750V RMS per plate, maximum DC output current of 250mA (with a voltage drop of approximately 67V at that current), a peak inverse voltage rating of 2,800V, and a maximum input filter capacitor of 4µF. The EIA manufacturer code 188 confirms genuine General Electric, USA origin.

The 5R4GYA is a premium drop-in upgrade or restoration choice for vintage guitar amplifiers, hi-fi power supplies, and military surplus equipment calling for a 5R4-family octal rectifier. GE NOS examples are increasingly scarce and prized for their consistency and build quality.