“Synthesizer is working and tested however has the following issues.
Only the lower half of keys is responsive. From middle C up makes no sound.
All keys respond over MIDI, so an external MIDI keyboard or sequencer will not have a problem sounding those notes.
The pitch / mod wheels rubbing against each other slightly.
The original QuadraSynth is very rare and hard to find since it had less than 2 years of production before the QuadraSynth Plus replaced it.” Click here to visit listing on eBay