What is the 5977 vacuum tube?

The 5977 is a triode vacuum tube designed for preamp applications. Military subminiature..

What are the key specifications of the 5977?

Amplification factor μ ≈ 16, transconductance gm ≈ 4.5 mA/V, plate resistance rp ≈ 3.6 kΩ, max plate voltage 180 V, max plate dissipation 3.3 W, heater 6.3 V / 0.15 A.

Is the 5977 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 5977 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 5977 sound like?

Military subminiature.. 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.

5977 Triode Vacuum Tube

Medium-gain triode for driver and line stage applications

TriodeHeater 6.3 V · 0.15 ASubminiature 9-lead (flying leads, no socket)Raytheon 1958

Plate dissipation: 3.3W
Max plate voltage: 180V
Amplification factor: 16
Transconductance: 4.5mA/V
Plate resistance: 3.556kΩ

5977

Characteristics

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

HeaterIndirectly heated

Specifications of 5977 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.15 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 5977 — Limiting values
Plate voltageVa max	180 V
Plate dissipationPa max	3.3 W

Mechanical

Specifications of 5977 — Mechanical
Base	Subminiature 9-lead (flying leads, no socket)
Rarity	Rare
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 5977 — Small signal
Transconductance	4.5 mA/V
Plate resistance	3.6 kΩ
Amplification factor	16

Capacitances

Specifications of 5977 — Capacitances
Grid–cathode	2 pF
Grid–plate	1.3 pF
Plate–cathode	0.8 pF

Charactereditorial reading, not a measurement

Specifications of 5977 — Character
Gain	16%
Power	8%
Drive	96%
Linearity	92%

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

Typical operation

Canonical operating pointModel

B+: 150 V
Load: 7 kΩ
Va: 90 V
Ia: 3.87 mA
Vg: -4 V
Pd: 0.35 W
Gain: 20.2 dB

At Q: Norman Koren
μ: 15.9
gm: 2.85 mA/V
rp: 5.6 kΩ

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Using this tube

Applications

Voltage amplifier
Line stage

Generic triode preamp stage

Hi-Fi stereoHeadphone amp

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Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : Radiomuseum 5977 / tubebooks RaytheonActive model : Norman Koren

Manufacturer datasheets

5 manufacturer datasheets cross-checked for 59775 verified

5977 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Radiomuseum 5977 / tubebooks Raytheon
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Norman Koren

Context

The 5977 is a indirectly-heated triode from Raytheon, introduced around 1958. It provides a gain factor (μ) of 16 with 3556Ω plate resistance. Commonly used in preamp applications. Military subminiature.

History

Introduced: 1958
Manufacturer: Raytheon
Era: Golden Age

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