What is the 6GB5 vacuum tube?

The 6GB5 (6GB5 / EL500) is a tetrode vacuum tube designed for sweep / power (se/pp) applications. European sweep tube. Good audio pentode..

What is a 6GB5 substitute or equivalent?

Direct equivalents to the 6GB5 include EL500, PL500. 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.

What are the key specifications of the 6GB5?

Transconductance gm ≈ 8 mA/V, max plate voltage 275 V, max plate dissipation 17 W, heater 6.3 V / 1.38 A.

Is the 6GB5 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6GB5 as Common 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 6GB5 sound like?

European sweep tube. Good audio pentode.. 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.

6GB5 EL500 Tetrode Vacuum Tube

Also known as EL500 · PL500

Beam power tetrode rated at 17W for high-power output stages

TetrodeHeater 6.3 V · 1.38 A9-pin MagnovalMullard·RCA 1960

Plate dissipation: 17W
Max plate voltage: 275V
Transconductance: 8mA/V

6GB5

Characteristics

Datasheet values, once each. Every value cites its sheet.

HeaterIndirectly heated

Specifications of 6GB5 — Heater
Heater voltageVh	6.3 V
Heater currentIh	1.38 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6GB5 — Limiting values
Plate voltageVa max	275 V
Plate dissipationPa max	17 W

Mechanical

Specifications of 6GB5 — Mechanical
Base	9-pin Magnoval
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 6GB5 — Small signal
Transconductance	8 mA/V

Capacitances

Specifications of 6GB5 — Capacitances
Input	12 pF
Grid–plate	0.7 pF
Output	8 pF

Charactereditorial reading, not a measurement

Specifications of 6GB5 — Character
Gain	0%
Power	43%
Drive	50%
Linearity	75%

datasheet cited · model or editorial reading · catalogue value, no citation attached yet · nothing invented

Using this tube

No interactive loadline model for this tube yet — download a SPICE model below to simulate it in LTspice or ngspice.

Applications

High-power output

Generic tetrode sweep / power (se/pp) stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : audit-us_a (CLEAN — matches canonical datasheet)

Manufacturer datasheets

2 manufacturer datasheets cross-checked for 6GB5 / EL5002 verified

6GB5 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: audit-us_a (CLEAN — matches canonical datasheet)
Reviewed: 2026-05-29
Status: DataModelCalc
Model: under review

Context

The 6GB5 is a indirectly-heated beam tetrode from Mullard·RCA, introduced around 1960. Commonly used in sweep / power (se/pp) applications. European sweep tube. Good audio pentode.

History

Introduced: 1960
Manufacturer: Mullard·RCA
Era: Late Production

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