The EF37A was a low noise version of the EF36. It was intended for use in low level audio amplifying stages (A. F. amplifier).
This valve is branded 'Miniwatt' so presumably it was marketed under the Philips 'Miniwatt' brand. It has a date code (EP2/B8L) which indicates that it was made in Mullard's Blackburn works in December 1958
Manufactured by: Mullard, Blackburn, England.
Sharp cut-off; 6,3 Volt indirectly heated cathode

Physical Description

Tubular glass bulb with top cap and octal base with seven pins present. Bulb is coated with red metallic screening paint

More Information