Bob Heil, godfather of the modern rock sound system and inventor of the voice-bending ‘Talk Box’ – obituary

Bob Heil, who has died aged 83, was an audio engineer with two claims to fame. He was the godfather of the modern sound system used by touring rock bands, beginning with the Grateful Dead; and he invented the Talk Box, a voice-bending gizmo made famous by Peter Frampton in the 1970s.