What is the 5AQ5 vacuum tube?

The 5AQ5 is a tetrode vacuum tube designed for power applications. 5V heater variant..

What is a 5AQ5 substitute or equivalent?

Direct equivalents to the 5AQ5 include 6AQ5. 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 5AQ5?

Amplification factor μ ≈ 10, transconductance gm ≈ 4.1 mA/V, plate resistance rp ≈ 52.0 kΩ, max plate voltage 275 V, max plate dissipation 12 W, heater 4.7 V / 0.6 A.

Is the 5AQ5 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 5AQ5 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 5AQ5 sound like?

5V heater variant.. 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.

5AQ5 Tetrode Vacuum Tube

Also known as 6AQ5

Beam power tetrode rated at 12W for high-power output stages

TetrodeHeater 4.7 V · 0.6 A7-pin MiniatureRCA 1952

Plate dissipation: 12W
Max plate voltage: 275V
Transconductance: 4.1mA/V

5AQ5

Characteristics

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

HeaterIndirectly heated

Specifications of 5AQ5 — Heater
Heater voltageVh	4.7 V
Heater currentIh	0.6 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 5AQ5 — Limiting values
Plate voltageVa max	275 V
Plate dissipationPa max	12 W

Mechanical

Specifications of 5AQ5 — Mechanical
Base	7-pin Miniature
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 5AQ5 — Small signal
Transconductance	4.1 mA/V
Plate resistance	52 kΩ
Amplification factor	10

Capacitances

Specifications of 5AQ5 — Capacitances
Input	8 pF
Grid–plate	0.4 pF
Output	8.5 pF

Charactereditorial reading, not a measurement

Specifications of 5AQ5 — Character
Gain	10%
Power	30%
Drive	48%
Linearity	95%

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

Typical operation

Conditions published by the manufacturers, one row per condition. Nothing is computed.

Typical operation
Setup	Va	Vg1 / Rk	Ia	gm	μ	rp	Source
Class A, single-endedtriode connection · fixed bias	250 V	-12.5 V	49.5 mA	4.8 mA/V	9.5	2 kΩ	OCR, to be checked Tung-Sol · 1959 · p. 2 · transcript

Using this tube

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : datasheet4u 5AQ5Active model : Koren pentode

Manufacturer datasheets

2 manufacturer datasheets cross-checked for 5AQ52 verified

5AQ5 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: datasheet4u 5AQ5
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The 5AQ5 is a indirectly-heated beam tetrode from RCA, introduced around 1952. It provides a gain factor (μ) of 10 with 52.0kΩ plate resistance. Commonly used in power applications. 5V heater variant.

History

Introduced: 1952
Manufacturer: RCA
Era: Golden Age

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