Karl (born in 1952) already soldered apart the first trombone in 1968 in the Große Allee at Master Gronitz. In 1971, he passed the journeyman’s examination and thus became the national winner in the practical performance competition for young craftsmen.

In 1974 he was taken on at Gronitz and successfully passed the master craftsman’s examination in 1977.

Since 2017 Karl can also be found with his own workshop “Trumpet Service” in Theodorhof in Hamburg.