6BR7

Sharp Cutoff Pentode — Noval

Brimar

Known Equivalents & Substitutes

6059CV5215

Similar Tubes (Not Drop-In Compatible)

6267

American designation for EF86 — similar function but different pinout

Similar low-noise pentode on Noval base with higher Gm (1.8 vs 1.25 mA/V) — different operating points, not pin-compatible

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)300V

Screen Voltage (max)Screen Voltage (max)125V

Anode Dissipation (max)Anode Dissipation (max)1.75W

Typical Operating

Anode Voltage (typical)Anode Voltage (typical)250V

Screen Voltage (typical)Screen Voltage (typical)100V

Grid 1 Bias VoltageGrid Voltage-3V

Anode CurrentAnode Current2.1mA

Screen CurrentScreen Current

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current0.15A

Notes

The 6BR7 is specifically designed for low-noise microphone and pickup preamplifier applications.
Typical operating conditions at Va=250V, Vg2=100V, Vg1=-3V: Ia=2.1mA, Ig2=0.6mA, Rp=2.5MΩ, Gm=1250 umhos.
Maximum ratings: plate voltage 300V, screen voltage 125V, plate dissipation 1.75W.
The low plate current and high Rp make this tube unsuitable as a general-purpose pentode — it is specifically optimised for low-noise voltage gain.

Pin Layout — Noval

1Internal Shield

2Anode

3Suppressor Grid (g3)

References