BARR & STROUD VARIABLE FILTER TYPE EF-3 Effects Pedal This is a monster of

This is a monster of a pedal - big

a step-up transformer is required for use in North America

we advise that it's a wise move to fit a modern driver in these old amps: it depends on what you want to use it for

All main components are original to amp

the 'Phase' delay is at minimum and vice versa

BARR & STROUD VARIABLE FILTER TYPE EF-3 Effects Pedal This is a monster ofOffered for sale is this Barr & Stroud Variable Filter EF 3 in excellent cosmetic condition and good working order (see photos for details). This is an extremely high spec dual filter unit as used by the BBC and various labs around the world: it offers very precise filtering. It requires BNC connectors adaptors for audio use. These units are famed for their high build quality and are designed for use in forensic audio they have also gained a following