Oberheim OB-X Keyboard 6 Voice with JL Cooper OBX Modifications Rare Synthesizer $1800 in Los Angeles, California For Sale

This is a very very rare synthesizer in excellent working condition.
It is a 6 voice Oberheim OB-X. It is a museum piece because it has the famous JL Cooper designed and manufactured modifications on all 6 voice boards. Super rare and useful modification.
It was serviced and repaired by JL, a former Oberheim employee who was their number one technician. I received it back from JL about 1.5 years ago. It has been used only three days since then.
You can read a lot more about this synth at
SoundonSound or Vintage Synth Explorer
All of the keys work. NO MIDI. This is a cv/gate machine and there are great programs to control these synths now, without installing midi.
The JL Cooper modification features a daughterboard attached to each voice card card. The daughterboard incorporates a CEM xxxx filter chip for a 4 pole low pass mode. The daughterboard is used in parallel with the normal stock 2 pole OBX filter and switching between the two is done using the half noise switch. The filter has selectable 12dB or 24dB (2- or 4-pole) rolloff, giving a nice choice of tone colours (apparently JL Cooper did this as a third party modification for OBX owners who wanted a 4-pole Moog type sound). In addition, there is a filter modulation to pedal on off switch.