David Cockerell designed one of the earliest synthesizers produced in the United Kingdom. The Synthi was introduced in the late 1960s by EMS Ltd. The unit, which came in a case with a KS keyboard, used patch cords to root reverb and ring modes. David also included two oscillators both with shape and level controllers as well as a frequency control. The design marked the beginning of many contributions to the industry over the years including his work on guitar effects pedals for Mike Matthews in the 1980s.