What is the VT-168A vacuum tube?

The VT-168A is a tetrode vacuum tube designed for power applications. Military designation for 6Y6G / beam power output family..

What is a VT-168A substitute or equivalent?

Direct equivalents to the VT-168A include 6Y6G. 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 VT-168A?

Amplification factor μ ≈ 8, transconductance gm ≈ 6 mA/V, max plate voltage 750 V, max plate dissipation 30 W, heater 6.3 V / 0.45 A.

Is the VT-168A still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the VT-168A as Moderate 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 VT-168A sound like?

Military designation for 6Y6G / beam power output family.. 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.

VT-168A Tetrode Vacuum Tube

Also known as 6Y6G

Beam power tetrode rated at 30W for high-power output stages

TetrodeHeater 6.3 V · 0.45 AMedium 7-Pin Micanol (1625)RCA 1942

Plate dissipation: 30W
Max plate voltage: 750V
Transconductance: 6mA/V

VT-168A

Characteristics

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

HeaterIndirectly heated

Specifications of VT-168A — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.45 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of VT-168A — Limiting values
Plate voltageVa max	750 V
Plate dissipationPa max	30 W

Mechanical

Specifications of VT-168A — Mechanical
Base	Medium 7-Pin Micanol (1625)
Rarity	Moderate
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of VT-168A — Small signal
Transconductance	6 mA/V
Amplification factor	8

Capacitances

Specifications of VT-168A — Capacitances
Input	11 pF
Grid–plate	0.2 pF
Output	7 pF

Charactereditorial reading, not a measurement

Specifications of VT-168A — Character
Gain	8%
Power	75%
Drive	50%
Linearity	95%

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

Using this tube

Applications

High-power output

Generic tetrode power stage

PA/public address

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : vintelec 6Y6G (= VT-168A) · wording corrected: 6Y6G family, not 6V6Active model : Koren pentode

Manufacturer datasheets

2 manufacturer datasheets cross-checked for VT-168A2 verified

VT-168A DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: vintelec 6Y6G (= VT-168A) · wording corrected: 6Y6G family, not 6V6
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The VT-168A is a indirectly-heated beam tetrode from RCA, introduced around 1942. Commonly used in power applications. Military designation for 6Y6G / beam power output family.

History

Introduced: 1942
Manufacturer: RCA
Era: Pre-War

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