Mode: passive or active
This pickup consists of a conical brass pin which is 4 cm long and as thick as a pencil. This pin is simply put into a conical hole drilled into the top end of the foot of the bridge. If you turn this brass pin in the bridge, you can adapt the sound to your instrument.
Besides the passive version, available for 15 years now, two improved active versions has recently been launched by Michael Schäfer, who took over the manufacturing from Willy Balsereit: the aktiv and the studio model. For these models, a miniature preamp (sized 4 x 6 mm) has been built into the brass cone. Existing older versions can be updated by the manufacturer.
The Bassbalsereit aktiv and studio models work with 7–48 V phantom power. While the aktiv can be used on balanced or unbalanced inputs, a balanced input (e.g. mixing console) is mandatory for the studio model. For the aktiv model, a DI box with phantom power supply is available, so it can easily be used with all kind of bassamps and mixing consoles.
available at www.kontrabass-atelier.de