# Digital Synth PRA32-U Parameter Guide v3.3.2

- 2026-03-14 ISGK Instruments
- <https://github.com/risgk/digital-synth-pra32-u>

## Control Change Parameters

- Notes
    - $1 : Disabled in Paraphonic Mode
    - $2 : Disabled if Osc 1 Wave is not Sin or Pls
- Osc 1 Wave [Saw|Sin|-|Tri|-|Pls]
    - 0, 6-12: Saw Wave
    - 1, 25 (13-38): Sine Wave (Shape adjustable)
    - 2, 50 (39-63): Triangle Wave
    - 3, 75 (64-88): Triangle Wave
    - 4, 100 (89-114): Pulse Wave (Shape adjustable)
    - 5, 127 (115-127): Pulse Wave (Shape adjustable)
- Osc 1 Shape $2
    - Sine Wave (Phase Modulation): Modulation Depth
    - Pulse Wave (= 1st Saw + Phase Shifted 2nd Saw)
        - 0: Pulse Width 50%, or 2nd Saw Phase 50% (min)
        - 64: Pulse Width 25%, or 2nd Saw Phase 75%
        - 96: Pulse Width 12.5%, or 2nd Saw Phase 87.5%
        - 127: Pulse Width 0.4%, or 2nd Saw Phase 99.6% (max)
- Osc 1 Morph $2
    - Sine Wave (Phase Modulation): Frequency Ratio of Modulator
        - 0 (0-1): Ratio 0.5 (min)
        - 4 (2-5): Ratio 1.0
        - 8 (6-9): Ratio 1.5
        - 12 (10-13): Ratio 2.0
        - 20 (18-21): Ratio 3.0
        - 28 (26-29): Ratio 3.5
        - 108 (106-109): Ratio 14.0
        - 124 (122-125): Ratio 16.0
        - 127 (126-127): Ratio 16.5 (max)
    - Pulse Wave
        - 0: Pulse 100% = Saw 100% + Reverse Saw 100% (min)
        - 32: Pulse 50% + Saw 50% = Saw 100% + Reverse Saw 50%
        - 64: Saw 100%
        - 96: Saw 100% + Saw 50%
        - 127: Saw 100% + Saw 100% (max)
- Mixer Noise/Sub Osc [N|S]
    - -64 (0): Noise 100%
    - -63 (1), -62 (2): Noise 96.9%
    - -3 (61), -2 (62): Noise 3.1%
    - -1 (63): Noise 0%
    - +0 (64): Sub 0%
    - +1 (65), +2 (66): Sub Osc 3.1%
    - +61 (125), +62 (126): Sub Osc 96.9%
    - +63 (127): Sub Osc 100%
- Osc 2 Wave [Saw|Sin|-|Tri|Nos|Sqr]
    - 0, 6-12: Saw Wave
    - 1, 25 (13-38): Sine Wave
    - 2, 50 (39-63): Triangle Wave
    - 3, 75 (64-88): Triangle Wave
    - 4, 100 (89-114): White Noise
    - 5, 127 (115-127): Square Wave
- Osc 2 Coarse [-|+]
    - -60 (4): -60 semitone (min)
    - +60 (124): +60 semitone (max)
- Osc 2 Pitch [-|+]
    - -55 (9): -12 semitone (min)
    - -41 (23): -5 semitone
    - -33 (31): -1 semitone
    - -32 (32): -50 cent
    - +0 (64): +0 cent
    - +32 (96): +50 cent
    - +33 (97): +1 semitone
    - +45 (109): +7 semitone
    - +55 (119): +12 semitone (max)
- Mixer Osc Mix [1|2]
- Filter Cutoff
    - 0: f = 13.0 Hz (min)
    - 61: f = 440 Hz
    - 64: f = 523.3 Hz
    - 121: f = 14080 kHz
    - 127: f = 19912.1 Hz (max)
- Filter Resonance
    -  8 (0-11): Q = 0.7 (min)
    - 16 (12-19): Q = 0.8
    - 24 (20-27): Q = 1.0
    - 32 (28-35): Q = 1.2
    - 40 (36-43): Q = 1.4
    - 48 (44-51): Q = 1.7
    - 56 (52-59): Q = 2.0
    - 64 (60-67): Q = 2.4
    - 72 (68-75): Q = 2.8
    - 80 (76-83): Q = 3.4
    - 88 (84-91): Q = 4.0
    - 96 (92-99): Q = 4.8
    - 104 (100-107): Q = 5.6
    - 112 (108-115): Q = 6.7
    - 120 (116-127): Q = 8.0 (max)
- Filter EG Amt [-|+], LFO Filter Amt [-|+]
    - -60 (4): -60 (min)
    - +60 (124): +60 (max)
- Filter Key Track [0.0|0.5|1.0] $1
    - 0 (0-31): 0.0
    - 64 (32-95): 0.5
    - 127 (96-127): 1.0
- EG Attack, Amp Attack
    - 0: 0.7 ms
    - 64: 63.2 ms
    - 127: 5.9 s
- EG Decay, Amp Decay
    - 0: 2 ms
    - 64: 200 ms
    - 126: 17.3 s
    - 127: No Decay
- EG Release, Amp Release
    - 0: 2 ms
    - 64: 200 ms
    - 127: 18.6 s
- EG Osc Amt [-|+], LFO Osc Amt [-|+]
    - Pitch
        - -61 (3): -30 semitone (min)
        - -55 (9): -24 semitone
        - -43 (21): -12 semitone
        - -33 (31): -2 semitone
        - -32 (32): -100 cent
        - +0 (64): +0 cent
        - +32 (96): +100 cent
        - +33 (97): +2 semitone
        - +43 (107): +12 semitone
        - +55 (119): +24 semitone
        - +61 (125): +30 semitone (max)
    - Shape
        - -63 (1): Shape -252 (min)
        - +63 (127): Shape +252 (max)
- EG Osc Dst [P|2P|1S], LFO Osc Dst [P|2P|1S]
    - 0, 3-31: Osc 1 & 2 Pitch
    - 1, 64 (32-95): Osc 2 Pitch
    - 2, 127 (96-127): Osc 1 Shape
- Voice Mode [Pol|Par|-|Mon|LP|Lgt]
    - 0, 6-12: Polyphonic (LFO Single Trigger)
    - 1, 25 (13-38): Paraphonic (LFO Single Trigger)
    - 2, 50 (39-63): Monophonic (EG & LFO Multi Trigger)
    - 3, 75 (64-88): Monophonic (EG & LFO Multi Trigger)
    - 4, 100 (89-114): Legato Portamento (Monophonic, EG & LFO Single Trigger, Auto Portamento)
    - 5, 127 (115-127): Legato (Monophonic, EG & LFO Single Trigger)
- Portamento
    - 0: Portamento Time 0 ms
    - 1: Portamento Time 1.1 ms
    - 64: Portamento Time 100 ms
    - 127: Portamento Time 9.3 s
- LFO Wave [Tri|Sin|-|Saw|SH|Sqr]
    - 0, 6-12: Triangle Wave (Key Trigger Off, -0.5 to +0.5)
    - 1, 25 (13-38): Sine Wave (Key Trigger Off, -0.5 to +0.5)
    - 2, 50 (39-63): Saw Wave (Key Trigger On, -0.5 to +0.5)
    - 3, 75 (64-88): Saw Wave (Key Trigger On, -0.5 to +0.5)
    - 4, 100 (89-114): Sample & Hold (Key Trigger On, -0.5 to +0.5)
    - 5, 127 (115-127): Square Wave (Key Trigger On, 0.0 to 1.0)
- LFO Rate
    - 0: 0.068 Hz (min)
    - 64: 2.7 Hz
    - 80: 6.9 Hz
    - 127: 103.8Hz (max)
- LFO Depth
    - The actual LFO depth is the "LFO Depth" value plus the "Modulation" value
- LFO Fade Time
    - 0: 0 ms (min)
    - 1: 9.6 ms
    - 64: 1.0 s
    - 127: 9.6 s (max)
- Filter Mode [LP|HP]
    - 0, 2-63: Low Pass
    - 1, 127 (64-127): High Pass
- EG Amp Mod [Off|On]
    - 0, 2-63: Off
    - 1, 127 (64-127): On, Amp ADSR = EG ADSR
- Release = Decay [Off|On]
    - 0, 2-63: Off
    - 1, 127 (64-127): On, EG Release = EG Decay and Amp Release = Amp Decay
        - **NOTE**: EG Velocity Sensitivity and Amp Velocity Sensitivity works independently
- Pitch Bend Range
    - 0: 0 semitone (min)
    - 60: 60 semitone (max)
- Breath Filter Amt [-|+]
    - -60 (4): -60 (min)
    - +60 (124): +60 (max)
- Breath Amp Mod [Off|Qad|Lin]
    - 0, 3-31: Off
    - 1, 64 (32-95): Quadratic Curve
    - 2, 127 (96-127): Liniear Curve
- Voice Assign Mode [1|2]
    - 0, 2-63: Mode 1, Free voice with next number has priority in Polyphonic/Paraphonic Mode, Release is effective
    - 1, 127 (64-127): Mode 2, Free voice with small number has priority in Polyphonic/Paraphonic Mode, Portamento is effective
- Chorus Rate
    - 0: LFO Frequency 0.012 Hz (min)
    - 64: LFO Frequency 0.48 Hz
    - 127: LFO Frequency 18.4 Hz (max)
- Chorus Depth
    - 0: Delay Time +/- 0 ms (min)
    - 32: Delay Time +/- 1.3 ms
    - 64: Delay Time +/- 2.7 ms
    - 126: Delay Time +/- 5.3 ms (max)
- Delay Feedback
    - 0: Feedback 0% (min)
    - 64: Feedback 25%
    - 127: Feedback 49.6% (max)
- Delay Time
    - 0: 1 ms (min)
    - 5: 6 ms
    - 6: 8 ms
    - 7: 10 ms
    - 12: 20 ms
    - 27: 50 ms
    - 42: 100 ms = eighth note time at 300 BPM
    - 57: 150 ms = eighth note time at 200 BPM
    - 62: 166.7 ms = eighth note time at 180 BPM
    - 64: 173.3 ms
    - 72: 200 ms = eighth note time at 150 BPM
    - 87: 250 ms = eighth note time at 120 BPM
    - 93: 270 ms
    - 102: 300 ms = eighth note time at 100 BPM
    - 112: 333.3 ms (max)
- Delay Mode [S|P]
    - 0, 2-63: Stereo Delay
    - 1, 127 (64-127): Ping Pong Delay