The Harry Klein Club is one of the two unofficial successors of the ultrasound, as the shareholders of the operating “Kleinharry GmbH” are recruited from the vicinity of this former club at Munich’s Ostbahnhof. The Rote Sonne, which opened in August 2005, is seen as the second successor due to the involvement of the former ultrasound booker DJ Upstart. The naming (Harry Klein is the assistant to the commissioner in the ZDF series Derrick) is also due to a legal dispute that the ultrasound led with the ZDF after the techno club was associated with drugs in a crime series on the station. After the second location of the ultrasound was closed at the end of the Kunstpark Ost on January 31, 2003, there had been suspicions within the scene about an ultrasound III, which had only been dispelled with the opening of Harry Klein on September 4, 2003 in the Optimol factory .
In 2010, Harry Klein, like several other clubs on the Optimol site, moved to a new location on Sonnenstrasse in downtown Munich, where a lively club life had already settled in previous years. It reopened there on June 24, 2010 at Sonnenstrasse 8