Expert Sleepers Lorelei
Analog VCO with quadrature sines and simultaneous waveshaping
8 HP Eurorack module
Lorelei is a 100% analog VCO using discrete transistor OTAs, offering three simultaneous waveform outputs: square/pulse, sine/pseudo-triangle, and cosine/pseudo-saw. All three outputs are shaped at once by a single waveshape control, which progressively morphs the square toward a triangle and the quadrature sine pair toward triangle/saw-like waveforms. A unique cross-modulation input acts as a voltage-controlled inhibitor rather than a hard sync, giving a wide palette of timbres depending on the waveform and amplitude of the syncing signal.
Features
- Three simultaneous waveform outputs: square/pulse, sine/pseudo-triangle, cosine/pseudo-saw
- Single waveshape control morphs all three outputs simultaneously
- Quadrature (90° phase-shifted) sine outputs enable stereo/rotation patching without extra modules
- Cross-modulation input gradually inhibits oscillation above ~3.3V — smoother than hard sync
- X-Mod timbre depends on shape AND amplitude of syncing signal for wide palette of effects
- Linear FM input for through-zero FM and audio-rate modulation
- Exponential FM input with dedicated front-panel attenuator
- Shape CV input with dedicated front-panel attenuator for envelope/LFO waveshape modulation
- At waveshape midpoint, perceived pitch of sine/cosine outputs doubles due to waveform folding
- 8-position octave selector switch (white) for coarse register selection
- Tune knob (blue) adjusts pitch approximately ±1 octave for fine-tuning
- 100% analog circuit using discrete transistor OTAs throughout
Controls & Jacks (13)
- V/Oct
- Lin FM
- Exp FM
- X-Mod
- Shape CV
- Square Out
- Sine Out
- Cosine Out
- Octave
- Tune
- Exp FM Attenuator
- Shape
- Shape CV Attenuator
How-To Guides
- Basic Analog Voice
- Quadrature Sine Drone
- Classic Oscillator Hard Sync
- Waveshape Timbre Modulation
- Exponential FM Bell Tones
- X-Mod Pulse Width Exploration
Explore the interactive Lorelei panel on BleepDex — tap any control to learn what it does.
