What is the E810F vacuum tube?

The E810F (E810F / 7788) is a pentode vacuum tube designed for preamp / driver applications. Frame-grid. Phenomenal transconductance..

What is a E810F substitute or equivalent?

Direct equivalents to the E810F include 7788. 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 E810F?

Amplification factor μ ≈ 57, transconductance gm ≈ 50 mA/V, plate resistance rp ≈ 42.0 kΩ, max plate voltage 250 V, max plate dissipation 5 W, heater 6.3 V / 0.34 A.

Is the E810F still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the E810F as Sought-after 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 E810F sound like?

Frame-grid. Phenomenal transconductance.. 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.

E810F 7788 Pentode Vacuum Tube

Also known as 7788

Small-signal pentode for low-noise voltage amplification

PentodeHeater 6.3 V · 0.34 A9-pin NovalPhilips·Valvo 1960

Plate dissipation: 5W
Max plate voltage: 250V
Max screen voltage: 200V
Max cathode current: 50mA
Transconductance: 50mA/V

E810F

Characteristics

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

HeaterIndirectly heated

Specifications of E810F — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.34 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of E810F — Limiting values
Plate voltageVa max	250 V
Screen voltageVg2 max	200 V
Plate dissipationPa max	5 W
Cathode currentIk max	50 mA

Mechanical

Specifications of E810F — Mechanical
Base	9-pin Noval
Rarity	Sought-after
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of E810F — Small signal
Transconductance	50 mA/V
Plate resistance	42 kΩ
Amplification factor	57

Capacitances

Specifications of E810F — Capacitances
Input	14.5 pF
Grid–plate	0.036 pF
Output	3.5 pF

Charactereditorial reading, not a measurement

Specifications of E810F — Character
Gain	57%
Power	13%
Drive	58%
Linearity	72%

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

Using this tube

Interactive loadline calculator not available for this tube yet — it needs calibrated Koren or Ayumi parameters.

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026

Manufacturer datasheets

3 manufacturer datasheets cross-checked for E810F / 77883 verified

E810F DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Philips·Valvo
Reviewed: 2026-05-29
Status: DataModelCalc
Model: under review

Context

The E810F is a indirectly-heated pentode from Philips·Valvo, introduced around 1960. It provides a gain factor (μ) of 57 with 42.0kΩ plate resistance. Commonly used in preamp / driver applications. Frame-grid. Phenomenal transconductance.

History

Introduced: 1960
Manufacturer: Philips·Valvo
Era: Late Production

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