Karim's background is atypical, since his adolescence he leads a double life as a musician and an electronic engineer. A drummer by training, he is also interested in the bass and the guitar while at the same time learning electronics on his own. Passionate about music and everything that is innovative in terms of sound, at the age of 17 he built his first effect pedal in a metal cake box that preciously contains a disto and a vibrato. It is by offering his services as a repairer of audio equipment that he enters the Studio Parisien in 1985 to give a new life to the amps of the groups Telephone, The Bandits, The Porte-Mentaux, Dave Stewart, Olive... to quote only them...

In 2003, he joined the mythical Ferber Studio as a technician and worked on Neve consoles. In 2004, he starts cutting up console slices to put them in racks. In 2009, while repairing a vintage effect pedal, he has the click: why not create my own pedals? The first Labo ★ K is born!