The Terrain Deluxe is an optical harmonic tremolo. It modulates the Bass and Treble frequencies separately: it uses an electronic crossover to split the signal, then it uses two independent optical tremolo circuits to modulate the two signals 180 Degrees out of phase with each other. The two signals are then mixed back together resulting in a tremolo that swirls and sparkles in three dimensional space. There is a switch to go between normal and harmonic modes, and a tone control that acts as a mixer between the high and low frequency signal paths.
There are speed and depth controls, a waveform selector, gain control, a tap tempo foot-switch (with speed multiplier), and expression pedal inputs for speed AND depth. Finally the optical circuitry ensures that there is electronic separation between the Low Frequency Oscillator and the signal path for an exceptional high fidelity sound.

• Harmonic Tremolo that uses and electronic crossover to modulate Bass and Treble frequencies separately for a big swirly sound.
• Optical modulation circuitry for high fidelity.
• Speed Control, with expression pedal input (Tip: CW, Ring: wiper, Sleeve: CCW).*
• Depth Control, with expression pedal input (Tip: CW, Ring: wiper, Sleeve: CCW).*
• Gain control.
• Tone control (mixes between high and low frequency paths. Centre is flat).
• Speed multiplier switch (quarter note, eighth note, eighth note triplet).
• Normal / Harmonic switch.
• Waveform switch (square, sine, triangle).
• Tap Tempo foot-switch.
• Full bypass using relays.
• 9V DC input. 80 mA.

Artwork by Sabine Elliott

* you can use synthesizer style control voltage signals on the expression pedal inputs, but you must to limit them to 0-5 VDC or risk damaging your tremolo.