INSTRUMENTS / GENERATORS
Kepler is a meticulous and so faithful recreation of the Roland JUNO-6™ Synthesizer. Very careful attention was paid to analyzing the oscillators, filters and interaction of the controls to make a sound that does justice to the original classic.
- Hold (latches on/off) - When activated holds the notes as if they were held down on the keyboard. Similar function to a sustain pedal. Useful for automation.
- Octave - Transpose the sound -1, 0 or +1 octave.
- Arp 1st Step Quantize - Arpeggiator playback will always be quantized to steps, i.e. Starts on next step.
- Velocity to Volume - Velocity affects the loudness of notes.
- Sub Osc Phase Aligned - Pulse Sub Oscillator's phase. Choose from 90° to 0° (The Juno 6 and Juno 60 ™ used 90° while the Juno 106™ used 0°).
- Chorus noise - Applies chorus to the noise generator.
- Chorus noise gate - As above and gates the noise with note on/off.
- HQ mode (High Quality) - Oversampling to improve aliasing.
- Volume (Knob) - Master output level.
- Arpeggiator On/Off - Activates or deactivates the Arpeggiator.
- Mode - Pitch cycle direction. Down, Up & Down, Up).
- Range - Octave range.
- Rate - Sets the playback speed of the Arpeggiator. Use the red LED switch above the slider to synchronize to song tempo.
LFO (Low Frequency Oscillator)
- Rate - LFO Speed. Use the red LED switch above the slider to synchronize to song tempo.
- Delay Time - Time it takes for the LFO to fade in. The fade is linear.
- Auto / Manual (Trigger Mode) - When Auto is selected the LFO is retriggered on the first key press. When Man is selected the LFO is retriggered using the button below the Auto/Man selector. This is only audible when the Delay Time parameter is non-zero.
DCO (Digitally Controlled Oscillator)
The Oscillator can create three different waveforms including a Pulse, Saw and Square wave. The Pulse waveform deserves some extra attention. It's like a Square wave, however the negative phase of the cycle can be flipped to the positive polarity and progressively along the length of the negative cycle. This keeps the pitch constant but the harmonic content or tone changes.
- LFO - How much the LFO modulates pitch.
- PWM (Pulse Width Modulation) - This slider will change the pulse width of the oscillator when the DCO Pulse is activated. There are 3 options on how to change the Pulse Width (see next parameter). With a setting of 50% the PWM will sound like a standard square wave. This is a 'duty-cycle' of 50%, meaning that it is high for half of the period and low for half of the period. A pulse wave with a duty cycle of 25% would be high for 25% of the period and low for 75% of the period. A low duty cycle will produce a brighter, more percussive sound, while a high duty cycle will produce a smoother, more mellow sound.
- DCO PWM Source - When LFO is selected, the LFO will modulate the Pulse Width of the Oscillator by the amount set by the PWM Slider. There are three modulation source options:
- LFO - The LFO modulates the Pulse Width.
- Man - The PWM Slider will manually control the Pulse Width.
- Env - The Envelope (ADSR) will modulate the Pulse Width.
- Waveform Augmentations - There are three buttons that add additional waveforms to the Oscillator:
- DCO Pulse active - The oscillator plays a Pulse in addition to the other selected waveforms.
- DCO Saw active - The oscillator plays a Sawtooth in addition to the other selected waveforms.
- DCO Sub active - The oscillator plays a -1 octave Square Wave in addition to the other selected waveforms.
- DCO Sub Volume - Level of the Square Sub Oscillator.
- Noise Volume - Level of the Noise oscillator (white noise).
HPF (High Pass Filter)
- Freq - Cutoff frequency of High-Pass filter. High-Pass filters remove frequencies below the cutoff.
VCF (Voltage-Controlled Filter)
- Freq - Cutoff frequency of low-pass filter.
- Res - Resonance of low-pass filter
- VCF polarity - Polarity of envelope. Determines if there is a positive or negative modulation of the cutoff frequency.
- Env - Amount the envelope modulates the low-pass filter's cutoff frequency.
- LFO - Amount the LFO modulates the low-pass filter's cutoff frequency.
- Kybd - Amount the keyboard note position (low to high) modulates the low-pass filter's cutoff frequency.
Daniel Schaack (code & design), Dario Sanfilippo (VCF modeling & DSP), Miroslav Krajcovic (interface).