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"The OB-Xa is a polyphonic Synthesizer with up to eight voices. Each voice inside the OB-Xa is a complete synthesizer, with two Voltage Controlled Oscillators (VCOs), two Voltage Controlled Filters (VCFs),a Voltage Controlled Amplifier (VCA), and two Envelope Generators.
The voices are arranged in two groups of four voices each, refered to as the Upper Voices and Lower Voices, respectively. Each group of voices gets control signals from its own associated control cirtcitry, which also contains the Low Frequency Oscillator for each group. There is a control circuit for the Upper Voices, and a second for the Lower Voices. Both control circuits are controlled by the OC-Xa's onboard computer.
It is a computer that looks at the keyboard and the front panel controls, and then communicates the appropriate information to the control circuits and to the voices themselves.
This particular unit has a MIDI kit installed. (see pictures)
This particular unit is missing one CM 3340. (see pictures)
The voices need tuning.
The keyboard assembly needs cleaning. (Some keys cut in and out)
Specifications
Synthesizer Components: 4, 6, or 8 voices; 3 Low Frequency Oscillators, Sample/Hold Circuit, Polyphonic Portamento, Pink Noise Source
Components In Each Voice:
2 Voltage Controlled Oscillators
2 Voltage Controlled Filters (2-Pole or 4-Pole low pass type, selectable)
2 Envelope Generators
1 Voltage Controlled Amplifier
Number of Programs: 120 Patch Programs, 8 Split Programs, 8 Double Programs
Keyboard: 5 Octaves (C to C)
Keyboard Modes: FULL, SPLIT (splits OB-Xa into two independant synthesizers), and DOUBLE (plays both independant synthesizers simultaneously); programmable split point and transpositions anywhere on the keyboard (in SPLIT or DOUBLE)
Output:
Stereo and Mono signal outputs (Output Level: 1 Volt peak to peak, 75K Ohms Impedance)
Cassette Interface inputs and outputs
Computer Interface (Parallel Interface)
Foot Controls:
Footswitches: Sustain, Hold, Program Advance
Foot Pedals: Filter, Vibrato
Power: 90-130 or 180-240 Volts AC, 50-60 Hz, 50 Watts
Dimensions: 40" (101.6 cm) wide, 20" (50.8 cm) deep, 6" (15.24 cm) high
Weight Without Case: 45 lbs. (20.41 kg)
Weight With Case: 109 lbs. (49.6 kg)"
