via this auction
"1960s Vintage Hohner Bass III Bass Synthesizer
Just restored! All key contacts cleaned, circuit board resoldered and bad voltage regulator replaced. It plays in tune!
The Bass III (or 3) has three sounds: String Bass (smooth), Guitar (plucky) and Tuba (round). And two controls: Volume and "Percussion" (attack). The "Percussion" feature can be turned on or off by pulling on the knob. There is also a fine tune control which is operated by a set screw. There is one output.
This thing has awesome low end (think of the bass sounds on records by The Doors) however, it is not a Moog. There's no CV input or output, no midi, just pure sixties analog goodness."