With his partner Noreen O'Riordan, director of the lighting department at Entec Sound & Light, John was father to two young sons - Kieran, aged 9, and Thomas, aged 6.
Among his many clients as a freelance engineer were George Michael, David Gilmour, Paul McCartney, Michael Jackson, Macy Gray, Annie Lennox, Christina Aguilera, The Pretenders, Phil Collins, Ozzy Osbourne, Luther Vandross, Sting, Sinead O'Connor, Eric Clapton and George Harrison.
In his early career, working mainly with Entec and Tasco, he laid the foundations of his skills working with bands including The Stranglers, Thomas Dolby, Squeeze, Wham, Grace Jones, Public Image Ltd and XTC.
Barbara Pendeleton, speaking on behalf of all at Entec Sound & Light, said they were "shocked and saddened" at John's death.
John's funeral takes place today (Wednesday 11 July): the family has asked for donations to be made to the Shooting Star Children's Hospice (www.shootingstar.org.uk).
A website has been set up by John's friends for tributes and memories (see address below).
(Lee Baldock)