Subconscious Communications
BRAP SY1
DUAL CHANNEL PERCUSSION SYNTHESIZER


Hybrid Homage to the Pearl Sy1


Model 73 - BrapSy1

General Architecture

BrapSy1 employs a VCO/VCF/VCA Signal Chain with LFO and Envelope modulators in Drum Synth tradition.  The BrapSy1 does implement this example with considerable contemporary variation.
 
Two Voices

Each of two BrapSy1 channels employís 2 digitally generated Sine wave oscillators.
Oscillator 1 is the VCO.  Oscillator 2 is the MOD VCO.  The Mod VCO has a LEVEL control for amplitude control and audio mixing.

* Oscillators conform to 1 Volt/8ve frequency control and have individual panel control and patching.  Inputs tolerate up to +/-10 Volts.

* The VCO and Mod oscillators sound across 6 channel MODES of operation. These modes vary oscillator connection and algorithm.



* BrapSy1 oscillators drive the analog Channel Filter; a 24dB/8ve voltage controlled Low Pass Filter.  The VCF along with the analog Channel VCA are provided Patching for VCF Frequency and VCA Attenuation Level.

* The Channel Volume Control (OUT) does not drive the VCA it is a classic Volume control.

Channel Triggering

Each BrapSy1 channel is Triggered by SY-1 compatible pads or typical Modular Synth GATE and/or TRIGGER signaling.  

The channelís illuminated SENSE panel control varies the trigger threshold and indicates trigger state.

A LINK panel switch routes Channel Oneís Trigger Input Source to Channel Two. Each Channel SENSE remains independent.

Integrated Modulators

Regardless of Mode, each channel has a Low Frequency Oscillator, Sample and Hold, and Switched Direction Voltage Sweep.   The LFO, S/H and Sweep drive the VCO and MOD oscillators.  The LFO can switch to drive the FILTER/VCA.

The VCF and VCA are controlled by the FILTER DECAY and RANGE panel controls as well as, their patch inputs.


Channel Modes

Mode A:  The VCO and MOD VCO sound simultaneous Sine waves.  Sine two has a LEVEL panel control to allow mixing.  

Mode B:  Alternating cycles of Sine waveforms whose independent time duration is Set by VCO TUNE and MOD TUNE.

Mode C:  Simple Through-zero FM.  MOD modulates the channel VCO to the degree set by MOD LEVEL.

    
Mode D:  The VCO Hard Synchronizes with the MOD VCO with independent panel control and patch for VCO Frequency and MOD LEVEL.  Mod Level distorts the waveform for harmonic content.

Mode E:   Classic Balanced Modulation.  Two Sine waveforms being multiplied.  MOD LEVEL again allows for distortion products.

Mode F:  Voltage Controlled Noise.  The VCO sets Spectrum Base rate of Noise Generation.  MOD VCO modulates Spectrum Rate.  MOD LEVEL sets Noise Loudness.  

Additional Features

Low Frequency Oscillator with Triangle and Square output waveforms able to internally modulate oscillators and filter.  External LFO output provided with WAVESEL selection of Tri/Square.

Sweep controls Oscillator Frequency.  The Sweep Panel Switch set the Direction of the Sweep and Range sets the extent of Sweep frequency modulation.

Each channel incorporates a ìStrike Toneî.   The Strike Tone drives the oscillator pitch to very high frequency for a few milli-seconds.  
 
Sy1 compatible pedals for MUTE and PITCH are compatible with the BrapSy1.


Technical

Power Requirement:          +12Vdc 190mA. -12Vdc 100mA.
Oscillator Sample Rate:         82kHz. 4k word Sine Table. 16 Bit DACís
Frequency Inputs:    1 Volt per Octave. +/-10Vdc tolerant.  Terminate at 16 Bit ADCís.
    Raw sample rate 82kHz.
VCF/VCA/Mode Inputs:    0-5 Volt to sweep range typical.  Tolerant +/-10V.

SHIPPING INCLUDED IN THE PRICE WHEN TERRITORY SELECTED