The B&W pre-amplifiers

In the late 1980s B&W loudspeakers was selling a "Cube" power amplifier manufactured for them by Rotel in Japan.This power amplifier used MOSFET output devices and was a mono-bloc with a maximum output of around 150 watts into 8 ohms.

Round about 1990 I was doing a lot of design work for B&W and the then owner Robert Trunz asked me to design a matching pre-amplifier control unit. Two versions were to be made; a completely passive unit with level controls and source switching for audiophiles and an active unit with remote control operation for everybody else. It is the passive unit which is shown here.

There were no less than 10 stereo inputs with separate selector switches for both source and tape outputs with a very high quality "Black" ALPs volume control and a balance control switching resistors in 1 dB steps.

The active version was pretty much identical except for an amplifier buffer stage; motorised switch and volume controls and remote control operation.

The designs were completed and shown to B&W distributors at a conference but they never went into production. Why? Well the company did not have its own electronics factory and the obvious factory, Rotel in Japan, was too busy to handle any more sub-contract work. We talked to Linn in Scotland about undertaking the manufacture but in the end this wasn't viable.


• Copyright 2009, 2010
Stan Curtis the hi-fi guru - B&W pre-amplifier-