Small Signal Pentodes

Click on the image to see a larger version

Label: Brimar
Type : 6BW7
This is an equivalent to the EF80 general purpose RF pentode. A bit noisy for audio applications although it has been used.

Label: Mullard
Type : EF83
Valve Code : 4G
Factory Code : D
Marked "Imported" this was manufactured at the Valvo Factory in Hamburg, Germany. The EF83 is a vari-μ (remote cut-off) pentode design for audio use in, for example, AGC circuits in tape recorders.

Label: Mullard
Type : EF86
Valve Code : 8Y5
Factory Code : L
Marked "Foreign" this was made in the Mazda factory in Brussels, Belgium. The EF86 is a purpose designed low-noise pentode for audio applications.

Label: Telefunken
Type : EF86
Valve Code : 213
This has the famous Telefunken diamond on the base. Notice how different the construction is to the Mullard examples.

Label: Mullard
Type : EF86
Factory Code : B
This one is British, made at the Blackburn factory.

Label: Mullard
Type : EF183
Valve Code : I4
Factory Code : B
Another Blackburn made, British valve. A vari-μ, frame grid, RF pentode. Not suitable for audio.

Home