What is the 6S45P vacuum tube?

The 6S45P (6S45P / 6С45П) is a triode vacuum tube designed for preamp / driver applications. Ultra-high Gm. Gold grid. Stunning speed..

What is a 6S45P substitute or equivalent?

Direct equivalents to the 6S45P include WE437A, 6C45Pi. 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 6S45P?

Amplification factor μ ≈ 52, transconductance gm ≈ 45 mA/V, plate resistance rp ≈ 1.1 kΩ, max plate voltage 150 V, max plate dissipation 7.8 W, heater 6.3 V / 0.44 A.

Is the 6S45P still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6S45P 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 6S45P sound like?

Ultra-high Gm. Gold grid. Stunning speed.. 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

←6S45P

← 6S3P-EV 6S4A →Compare → WE437A

6S45P 6S45P / 6С45П Triode Vacuum Tube

Triode6.3V / 0.44A9-pin Noval

SourceSoviet-Tubes 6С45П-Е datasheetReviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Medium-gain triode for driver and line stage applications

Datasheet ↗

6S45P / 6С45П — Reflector — triode vacuum tube — (1965)

1.1kΩ

45.0mA/V

11.0pF

4.0pF

1.90pF

GAIN52%

POWER20%

DRIVE99%

LINEARITY74%

SPECIFICATIONS

Heater6.3 V · 0.44 A

Max Plate Voltage150 V

Pa max7.8 W

Gain Factor52

gm45 mA/V

rp1.1 kΩ

Inter-electrode capacitances

Cgk11 pF

Cgp4 pF

Cpk1.9 pF

Pinout9-pin Noval

Era1965

RarityModerate

HEATER6.3V / 0.44A

MAX PLATE150V / 7.8W

BASEnoval

Source datasheets

1 manufacturer datasheets cross-checked for 6S45P / 6С45П

1 verified

EXECUTIVE SUMMARY

The 6S45P is a indirectly-heated triode from Reflector, introduced around 1965. It provides a gain factor (μ) of 52 with 1150Ω plate resistance. Commonly used in preamp / driver applications. Ultra-high Gm. Gold grid. Stunning speed.

APPLICATIONS

Push-pull outputVoltage amplifierHeadphone outputHigh-gain preamp

Generic triode preamp / driver stage

• Hi-Fi stereo• Headphone amp• Studio/recording

VS WE437A

μ +30%Rp +32%Pd +11%Full comparison →

HISTORY

Introduced1965ManufacturerReflector

Late Production

6S45P Datasheet

Frank's Electron Tube Pages · PDF

↗

METRIX TESTER

Test this tube on a Metrix

SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.

SIMILAR TRIODES

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