A Sonab R4000-2 FM tuner/amplifier dating from the early 1970s. Designed in Sweden and manufactured in England, these unusual receivers are well known for their minimalist Scandinavian styling and excellent sound quality.
This example is in good working order and has been serviced where appropriate. All controls have been cleaned with DeoxIT and the tuner and amplifier operate correctly.
Please note that the dial illumination bulbs and the power indicator lamp are not currently working. These should be straightforward for the next owner to replace if desired and do not affect the operation of the unit.
The original circuit diagram remains taped inside the top cover.
The amplifier uses DIN speaker sockets, so suitable DIN speaker plugs will be required (these are inexpensive and readily available). An external FM aerial will also be required unless you live in an area with a particularly strong signal.
A short demonstration video is included showing the FM tuning mechanism, which is slightly unusual compared with most receivers of the period.
Safety improvements
Like many hi-fi products of the early 1970s, this amplifier originally used a two-core mains lead with a floating metal chassis which can disguise safety issues. As a business seller I was not prepared to sell it in that condition.
A modern three-core mains cable has therefore been fitted and the chassis has been correctly bonded to protective earth. This significantly improves electrical safety while preserving normal operation. It was then PAT tested to ensure electrical safety. Thanks to the fully insulated DIN input system used by Sonab, this modification has not introduced any audible mains hum.
Please study the photographs carefully as they form part of the description. Everything shown in the photographs is included unless stated otherwise.
This amplifier will appeal to collectors of vintage Scandinavian hi-fi, Sonab equipment, classic FM receivers and 1970s audio equipment. It is equally suitable for someone looking for an unusual everyday amplifier with distinctive styling and excellent sound quality.
