Telefunken premium version of EF86 — same electricals, even tighter specs and lower microphonics
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)300V
Anode Dissipation (max)Anode Dissipation (max)1W
Screen Voltage (max)Screen Voltage (max)200V
Typical Operating
Anode Voltage (typical)Anode Voltage (typical)250V
Notes
The CV4086 is the British military specification version of the EF86 with tighter parameter tolerances, improved microphonic performance, and ruggedised construction.
The EF86 is one of the most popular audio preamplifier pentodes, widely used in guitar amplifiers (Vox AC30) and hi-fi equipment.
Typical operation at Va=250V, Vg2=140V, Vg=-2V: Ia=3mA, Ig2=0.6mA, gm=1800 umhos, Rp=2500kΩ, mu=4500. Extremely high mu and plate resistance characteristic of a low-noise audio pentode.