We have had surprisingly few repairs to older Oberheim equipment.
One of these was an Oberheim OB1. There is an urban legend that the Alec Guinness character in Star Wars got his name from this machine.
This was a programmable monosynth with many of the features of the SEM but with a keyboard and 8 programmable memories. Lots of knobs and switches, not all of which were memorised, and implemented without a microprocessor so the logic was all discrete and easily replaceable.
All the control knobs with black caps were programmable, also the slide switches in the Oscillator and Filter sections.The pitch bend mechanism is a sprung lever as is visible in the picture. The Filter is switchable between 12dB and 24dB modes and is made with similar IC’s to the SEM which was Oberheim’s first product.