What is a 6021 substitute or equivalent?

Direct equivalents to the 6021 include 6111, 6112 (sister submini duals). 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 6021?

Amplification factor μ ≈ 35, transconductance gm ≈ 5.4 mA/V, plate resistance rp ≈ 6.5 kΩ, max plate voltage 165 V, max plate dissipation 0.7 W, heater 6.3 V / 0.3 A.

Is the 6021 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6021 as Rare 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 6021 sound like?

Raytheon CK6021 subminiature dual triode (cousin of 6111). Flying-lead 8-pin construction, no socket. Designed for missile / aerospace gear, popular today for ultra-compact preamp builds.. 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

←6021

← 6005 6072 →Compare → 6111

6021 Triode Vacuum Tube

Q: What is the 6021 vacuum tube?

The 6021 is a triode vacuum tube designed for preamp / driver applications. Raytheon CK6021 subminiature dual triode (cousin of 6111). Flying-lead 8-pin construction, no socket. Designed for missile / aerospace gear, popular today for ultra-compact preamp builds..

Dual triode6.3V / 0.3A8-pin Submini (flying leads)SPICE

SourceRaytheon CK6021 datasheetReviewed2026-05-29StatusDataModelCalcModelNorman KorenPDF

Medium-gain triode for driver and line stage applications

Datasheet ↗SPICE

6021 — Raytheon·CBS — triode vacuum tube — (1955)

6.5kΩ

5.4mA/V

2.4pF

1.5pF

0.28pF

GAIN35%

POWER2%

DRIVE94%

LINEARITY83%

SPECIFICATIONS

Heater6.3 V · 0.3 A

Max Plate Voltage165 V

Pa max0.7 W

Gain Factor35

gm5.4 mA/V

rp6.5 kΩ

Inter-electrode capacitances

Cgk2.4 pF

Cgp1.5 pF

Cpk0.28 pF

Pinout8-pin Submini (flying leads)

Era1955

RarityRare

HEATER6.3V / 0.3A

MAX PLATE165V / 0.7W

BASEsubmini-8

SECTIONS2 (dual)

Source datasheets

9 manufacturer datasheets cross-checked for 6021

9 verified

TYPICAL OPERATING POINT

Va90V

Ia3.37mA

Vg-1.5V

Pd0.3W

RL13kΩ

Av25.5dB

EXECUTIVE SUMMARY

The 6021 is a dual indirectly-heated triode from Raytheon·CBS, introduced around 1955. It provides a gain factor (μ) of 35 with 6500Ω plate resistance. Commonly used in preamp / driver applications. Raytheon CK6021 subminiature dual triode (cousin of 6111). Flying-lead 8-pin construction, no socket. Designed for missile / aerospace gear, popular today for ultra-compact preamp builds.

APPLICATIONS

Voltage amplifierPhase splitter

Generic triode preamp / driver stage

• Hi-Fi stereo

VS 6111

μ +75%Rp +63%Pd -36%Full comparison →

HISTORY

Introduced1955ManufacturerRaytheon·CBS

Golden Age

6021 Datasheet

Local mirror · PDF

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METRIX TESTER

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