What is the KT150 vacuum tube?

The KT150 is a tetrode vacuum tube designed for power (pp) applications. Maximum power beam tetrode..

What is a KT150 substitute or equivalent?

Direct equivalents to the KT150 include KT88/KT120. 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 KT150?

Transconductance gm ≈ 12.6 mA/V, plate resistance rp ≈ 3.0 kΩ, max plate voltage 850 V, max plate dissipation 70 W, heater 6.3 V / 2 A.

Is the KT150 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the KT150 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 KT150 sound like?

Maximum power beam tetrode.. 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.

KT150 Tetrode Vacuum Tube

Also known as KT88 · KT120

Beam power tetrode rated at 70W for high-power output stages

TetrodeHeater 6.3 V · 2 AOctalTung-Sol 2013

Plate dissipation: 70W
Max plate voltage: 850V
Max screen voltage: 225V
Transconductance: 12.6mA/V

KT150

Characteristics

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

HeaterIndirectly heated

Specifications of KT150 — Heater
Heater voltageVh	6.3 V
Heater currentIh	2 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of KT150 — Limiting values
Plate voltageVa max	850 V
Screen voltageVg2 max	225 V
Plate dissipationPa max	70 W

Mechanical

Specifications of KT150 — Mechanical
Base	Octal
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of KT150 — Small signal
Transconductance	12.6 mA/V
Plate resistance	3 kΩ

Capacitances

Specifications of KT150 — Capacitances
Input	20.5 pF
Grid–plate	1.75 pF
Output	10 pF

Charactereditorial reading, not a measurement

Specifications of KT150 — Character
Gain	0%
Power	100%
Drive	97%
Linearity	75%

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

Using this tube

Applications

High-power output

Audio Research Reference 150SEPrimaLuna EVO 400

PA/public address

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : audit-us_b (CLEAN — matches canonical datasheet)Active model : Koren pentode

Manufacturer datasheets

1 manufacturer datasheets cross-checked for KT1501 verified

KT150 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: audit-us_b (CLEAN — matches canonical datasheet)
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The KT150 is a indirectly-heated beam tetrode from Tung-Sol, introduced around 2013. Commonly used in power (pp) applications. Maximum power beam tetrode.

History

Introduced: 2013
Manufacturer: Tung-Sol
Era: Modern

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