Holocene Electronics - SEICHE

SEICHE is a dual analog complex filter that combines two OTA-based 2-pole state-variable filters with wavefolding and internal FM/AM modulation. Each channel offers switchable lowpass, bandpass and highpass filtering, with an Overtones slider that introduces additional harmonics and distortion. If you push the resonance high enough and the filters will begin to self-oscillate, turning them into sound sources in their own right.

Both channels have dedicated Ping inputs for producing ringing, percussive tones, while the integrated wavefolders can turn self-oscillating sine waves into much richer sounds. Channel 1 can also modulate Channel 2 through internally routed FM or AM, with a Depth slider controlling the amount. Channel 1 operates at a lower frequency scale for modulation, while Channel 2 offers V/Oct tracking across more than five octaves. From conventional filtering to metallic, folded tones and punchy percussion, SEICHE has plenty of character even without an external oscillator. This is a flexible little sound-shaping machine with a healthy appetite for distortion.

Features:

• Dual analog complex filter with integrated wavefolding
• Two OTA-based 2-pole state-variable filters (12 dB/oct)
• Switchable lowpass, bandpass and highpass modes per channel
• Individual resonance and frequency controls
• Self-oscillation at high resonance settings
• Dedicated Ping input per channel for percussive sounds
• Individual Overtones sliders for wavefolding and harmonic distortion
• Internal FM and AM modulation from Channel 1 to Channel 2, with Off position
• Modulation Depth slider
• Channel 1 operates on a lower frequency scale for modulation
• Channel 2 supports V/Oct tracking over more than five octaves
• Independent audio inputs and outputs
• Individual gain controls and CV inputs