Each filter has independent cutoff and resonance controls. When combined, these filters create a bandpass mode - a hallmark of classic MS-20 synth family that surpasses the limitations of switchable filter designs. Both filters self-oscillate when resonance exceeds the oscillation point, allowing the SHSL to function as a dual CV-controllable sine wave oscillator. The series arrangement provides maximum flexibility: use one filter alone, both in parallel frequency ranges, or create a swept bandpass by converging cutoff frequencies. This topology delivers everything from gentle resonant sweeps to aggressive filter screaming.
SHSL has a dedicated preamp section which is inspired by Moogerfooger pedals providing beautiful coloring to the sound. The pre section can operate in array of modes from light saturation to pushing the amp into overdrive/distortion territory. Located before the filters, the preamp shapes your input signal before filtering, adding harmonic complexity and driving the filters harder for increased resonance and character. This arrangement mimics classic synthesizer signal flow where VCAs drive VCFs. The preamp transforms the SHSL from a transparent filter into a complete tone-shaping tool, adding weight to bass, grit to guitars, and warmth to digital synths.
Separate CV and expression inputs for each filter provide complete dynamic control for live performances and effortless integration with modular systems. So High So Low can also be used as a standalone CV controllable synth / oscillator. CV inputs accept ±8V control voltage from sequencers, LFOs, envelope generators, or any modular source. Expression inputs allow standard expression pedals to control filter cutoff in real-time, functioning like a voltage-controlled wah pedal. This dual-control architecture enables complex modulation routing: sequence one filter while manually controlling the other, or use LFOs to create rhythmic filter pumping. The SHSL bridges guitar pedals and eurorack worlds without compromise.