‘Crystal Palace’ capacitive fader designed by Dave Young. It was used in Brian Hodgson's music for 'The Machine Stops' in 1966.
In this device, an electric motor cannibalised from a variable-speed dictation machine turns a ‘capacitive’ vane. The vane is connected to the input of a FET amplifier via the gold nib of a Conway-Stewart fountain pen. There are a series of audio inputs and outputs wired within the unit which can be configured to produce different effects. Sixteen sounds could be smoothly combined using this device, opening up the possibility of rich sound montages.