What is the 6DK6 vacuum tube?

The 6DK6 is a pentode vacuum tube designed for preamp / if amp applications. Small sharp-cutoff TV pentode..

What is a 6DK6 substitute or equivalent?

Direct equivalents to the 6DK6 include 6CB6, 6DE6. 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 6DK6?

Transconductance gm ≈ 9.8 mA/V, plate resistance rp ≈ 350.0 kΩ, max plate voltage 330 V, max plate dissipation 2.3 W, heater 6.3 V / 0.3 A.

Is the 6DK6 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6DK6 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 6DK6 sound like?

Small sharp-cutoff TV 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.

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

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6DK6 Pentode Vacuum Tube

Pentode6.3V / 0.3A7-pin Miniature

Sourceaudit-us_a (CLEAN — matches canonical datasheet)Reviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Small-signal pentode for low-noise voltage amplification

Datasheet ↗

6DK6 — RCA·GE — pentode vacuum tube — (1955)

350.0kΩ

9.8mA/V

6.3pF

0.0pF

1.90pF

GAIN0%

POWER6%

DRIVE0%

LINEARITY75%

SPECIFICATIONS

Heater6.3 V · 0.3 A

Max Plate Voltage330 V

Pa max2.3 W

Gain Factor—

gm9.8 mA/V

rp350.0 kΩ

Inter-electrode capacitances

Cgk6.3 pF

Cgp0.02 pF

Cpk1.9 pF

Pinout7-pin Miniature

Era1955

RarityCommon

HEATER6.3V / 0.3A

MAX PLATE330V / 2.3W

BASEminiature-7

Source datasheets

3 manufacturer datasheets cross-checked for 6DK6

3 verified

EXECUTIVE SUMMARY

The 6DK6 is a indirectly-heated pentode from RCA·GE, introduced around 1955. Commonly used in preamp / if amp applications. Small sharp-cutoff TV pentode.

APPLICATIONS

Voltage amplifier

Generic pentode preamp / if amp stage

HISTORY

Introduced1955ManufacturerRCA·GE

Golden Age

6DK6 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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