"For those unfamiliar, this is a monophonic synthesizer and was among the first synthesizers to offer the ability to store presets. The unit can store 8 presets at one time using battery backed memory.
This particular unit has recently been calibrated and has had a new battery installed. Everything seems to be working great, although there may be the occasional crackle from a potentiometer.
The only issue that should me mentioned is that this OB-1 at one point was modified for use with some kind of sequencer. The modifications have been removed but there is a small hole in the front where a toggle switch had been mounted and a 1/4" hole in the back where a jack had been mounted. Both of these holes can easily be plugged. The front hole had been marked and the legending should be easily removable. There is also a balanced output installed to the back with a balancing transformer..."