bastl-instruments/kastle
Kastle (v1.5)
Kastle v1.5 is a mini modular synthesizer with a complex oscillator, voltage-controllable LFO, and stepped waveform generator. It features 6 synthesis modes, PITCH/TIMBRE/WAVESHAPE controls with CV inputs, a headphone output, and 2 I/O CV ports. Runs on 3x AA batteries or USB power.191
Capabilities 3
- Complex Oscillatorcomplex-oscillator
- 6 synthesis modes across main and secondary outputs: phase modulation, track & hold modulation, noise mode (main); phase distortion, formant synthesis, tonal noise mode (secondary). Mode selected by MODE jack voltage.191
- LFOlfo
- Voltage-controllable LFO with triangle and square/pulse outputs and a reset input. Rate modulated via RATE MOD jack and attenuator knob.191
- Stepped Voltage Generatorstepped-voltage-generator
- Rungler-inspired 8-bit shift register produces 8 different voltages. Pattern mode (random, 8-step, 16-step) set by BIT IN jack. Advances twice per LFO period.191
Jacks 17 — 10 in / 7 out
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (10) | |||
| BIT IN | cv | — | Controls stepped generator pattern mode. Low = 8-step loop; unconnected = 16-step loop; high = random pattern.191 |
| I/O L | mixed | 0V to 5V | Left channel of stereo I/O port; routes modulation/audio/clock to/from external gear. Input signals are rectified; responds only to 0–5V.191 |
| I/O R | mixed | 0V to 5V | Right channel of stereo I/O port; routes modulation/audio/clock to/from external gear. Input signals are rectified; responds only to 0–5V.191 |
| LFO RST | trigger | — | Resets LFO phase to highest point of triangle; useful for complex modulation or external clock sync.191 |
| MODE | cv | — | Selects synthesis mode. Unconnected = phase modulation / phase distortion; high (+) = track & hold / formant; low (−) = noise / tonal noise.191 |
| OSC OUT | audio | — | Main oscillator output; when another output is patched here, signals are passively mixed and sent to the OUT jack.191 |
| PITCH MOD | cv | — | CV input for pitch modulation; amount controlled by PITCH MOD knob.191 |
| RATE MOD | cv | — | CV input for LFO rate modulation; amount controlled by RATE MOD knob.191 |
| TIMBRE MOD | cv | — | CV input for timbre modulation; amount controlled by TIMBRE MOD knob.191 |
| WAVESHAPE | cv | — | CV input for waveshape modulation; also controls pulse width of OSC PULSE output.191 |
| Outputs (7) | |||
| + | cv | — | Fixed high voltage output; can set MODE high statically, offset modulation signals, or set BIT IN high.191 |
| - | cv | — | Ground/low output; can set MODE low statically, connect grounds between instruments, or set BIT IN low.191 |
| LFO PULSE | gate | — | Outputs LFO pulse wave in sync with triangle; high when triangle is rising, low when falling. Useful for synchronizing external equipment.191 |
| LFO TRIANGLE | cv | — | Outputs LFO triangle waveform; can be shaped by LFO RATE modulation or LFO RST triggering.191 |
| OUT | audio | — | Main output of the complex oscillator; can drive headphones directly.191 |
| SECONDARY OSC OUT | audio | — | Alternative waveform output from secondary oscillator; waveform shaped by WAVESHAPE parameter. Can modulate Kastle parameters, mix with OSC OUT, or be output via I/O jack.191 |
| STEPPED | cv | — | Outputs stepped random/looping voltages from a Rungler-inspired shift register. Generates 8 different voltages, twice per LFO period. Pattern depends on BIT IN state.191 |
Parameters 7
| Name | Type | Range | Behavior |
|---|---|---|---|
| LFO RATE | knob | — | Sets LFO speed. An LED near the knob displays the modulation rate.191 |
| OSC PITCH | knob | — | Controls the pitch of the main oscillator. The PITCH parameter controls the main oscillator.191 |
| OSC TIMBRE | knob | — | Sets the pitch of the modulating oscillator. In noise mode, controls the secondary oscillator that modulates amplitude of the final signal.191 |
| PITCH MOD | knob | — | Attenuator for the PITCH MOD CV input signal.191 |
| RATE MOD | knob | — | Attenuator for the RATE MOD CV input; useful for creating complex modulation curves.191 |
| TIMBRE MOD | knob | — | Attenuator for the TIMBRE MOD CV input signal.191 |
| WAVESHAPE | knob | — | Controls the 3rd synthesis parameter; meaning depends on synthesis mode. Also sets pulse width of OSC PULSE output. In phase modulation: sets modulation amount. In track & hold: sets comparator threshold/pulse width. In noise mode: controls loop length of playback. In formant synthesis: selects harmonic combinations.191 |
Firmware history 0 versions
No firmware history recorded.
References 2
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[192]
Bastl Kastle product pageproduct_page⚠ verified 2026-05-06 · manufacturer changed since last verified