Bastl Kastle v1.5 Due 7/5/2024

Experiment with lo-fi anywhere with this pocketable modular

The Kastle is a compact modular synthesizer that can be powered with batteries or via USB. It emits distinct modulations and inherently intricate sounds. It can be used in a self-contained manner or integrated into a larger setup. v1.5 consists of a complex oscillator and an LFO with a stepped waveform generator.


  • Complex oscillator
  • 3 synthesis modes on the main output: phase modulation, noise mode, track & hold modulation
  • 3 more modes on the secondary OSC output: phase distortion, tonal noise mode, formant synthesis
  • PITCH control with offset and CV input with attenuator
  • TIMBRE control with offset and CV input with attenuator
  • WAVESHAPE control with offset and CV input
  • Voltage controllable LFO with triangle and square outputs and reset input
  • Stepped voltage generator with random, 8 step and 16 step loop mode
  • 2 I/O CV ports that can be routed to any patch point
  • The main output can drive headphones
  • 3x AA battery operation or USB power selectable by a switch
  • Open source
  • Possibility of exchanging different LFO and OSC chips
  • Durable black & silver PCB enclosure

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