What is the EFL200 vacuum tube?

The EFL200 is a pentode vacuum tube designed for power applications.

What is a EFL200 substitute or equivalent?

Direct equivalents to the EFL200 include 6Y9. 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.

Is the EFL200 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the EFL200 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 EFL200 sound like?

Sonic character depends 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

EFL200 Pentode Vacuum Tube

Pentode + PentodeDecal2 sectionsAlso known as6Y9

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : rfparts EFL200/6Y9 frame-grid pentode

EFL200

In brief

Signal pentodePentode

μ: 38
gm: 22 mA/V
rp: 33 kΩ
Pa: 5 W

Power pentodePentode

μ: 38
gm: 22 mA/V
rp: 33 kΩ
Pa: 5 W

The EFL200-Pre is a indirectly-heated pentode from Philips, introduced around 1960. It provides a gain factor (μ) of 38 with 33.0kΩ plate resistance. Commonly used in preamp applications. Preamp section. The EFL200-Power is a indirectly-heated pentode from Philips, introduced around 1960. It provides a gain factor (μ) of 38 with 33.0kΩ plate resistance. Commonly used in power applications. Power section.

Limits

Specifications of EFL200-Pre — Signal pentode
Specification	Value	Source
Heater
Heater voltage	6.3 V	Datasheet
Heater current	0.83 A	Datasheet
LimitsDatasheet maximum ratings — not to be exceeded
Max Plate V	250 V	Datasheet
Pa max	5 W	Datasheet

Using this tube

Open the loadline calculator

APPLICATIONS

Phase splitter

Generic pentode power stage

Replace or compare

Sources

Manufacturer datasheets

Signal pentode

2 manufacturer datasheets cross-checked for EFL200 — Signal pentode2 verified

Power pentode

2 manufacturer datasheets cross-checked for EFL200 — Power pentode2 verified

EFL200 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: rfparts EFL200/6Y9 frame-grid pentode
Reviewed: 2026-05-29
Status: DataModelCalc
Model: SPICE model

Context

HISTORY

Introduced: 1960
Manufacturer: Philips
Era: Late Production

METRIX TESTER