Christophssen released 7" single on Planet Mu (as DJ Hekla), he also wrote liner notes for Hrvatski' debut album and made artwork and cover design for several Keith Fullerton Whitman albums on Kranky and (supposedly) some other RKK and Reckankreuzungsklankewerkzeuge releases.

Later Pieter Christophssen (Mr. P.C. C.P.) name was associated with Reckankreuzungsklankewerkzeuge imprint. Commenting rumors of his involvement with the label, Whitman first said that Mr. P.C. C.P. was a joint pseudonym for a group of record collectors, early electronic music enthusiasts, sound engineers, etc. but finally admitted that he is Pieter.