A continuous pitch analog synthesizer
Inspired by the Ondes Martenot's au ruban controller, the ET-4 is controlled by moving a finger along a reference keyboard shaped to provide tactile feedback. Dual pressure sensitive intensity keys control the amplitude of the ET-4's two independent analog oscillators. Combined with a filter, white noise generator and internal spring reverb the ET-4 is an expressive and versatile performance synthesizer.
Each oscillator has six different waveforms, including the classic sine wave of the Electro-Theremin and the Ondes Martenot's unique octiviant and white noise settings. A low-pass filter with variable cutoff frequency is used to shape the sound and this can also be controlled with an external expression pedal or CV source. A classic spring reverb unit is built into the instrument with independent controls for wet and dry output levels. A wide range of sounds can be created with the ET-4; from haunting ethereal sounds and deep bass grooves to sci-fi soundscapes and classical voicings. Plugs directly into a guitar or keyboard amplifier and is compatible with most effects and stompboxes. Every ET-4 is individually hand crafted in Canada using high quality components and select North American Walnut.
ET-4 Demo video by Robert Kilman. See more of the ET-4 in our Therevox Sessions video series.
From the oscillators and filter to the traditional spring reverb, the ET-4 is 100% analog. Each oscillator produces six waveforms: sine, triangle, rectified sine based on the octiviant setting of the Ondes Martenot, square wave, 30% pulse and 10% pulse. White noise is also available on osc 2.
Interface with external synthesizer gear with the separate control voltage (CV) outputs for the ring and pressure sensitive keys. The ring output is 1 volt per octave and the intensity keys produce a CV from 0 to +10 volts. The ET-4 also accepts an expression pedal or CV source to control the filter cutoff frequency.
Built by Hand
Each instrument is built by hand in our workshop. The ET-4 is crafted from select North American black walnut that has been hand rubbed with a natural oil finish. Inside we use only high quality components and hardware.
Always in Tune
Change tuning using the dedicated tuner output without making a sound. Select between oscillators using the tuner output switch on the front panel and quickly transpose keys or detune an oscillator, silently.
The finger ring allows expressive pitch control. This adjustable ring glides on a steel reinforced wire that will not slip or break, while depressions under each note provide tactile feedback. Dual pressure sensitive intensity keys allow for independent control of each oscillator's amplitude.
We offer customized keyboard overlays for different scales and modes. How about a guitar fretboard instead of a keyboard or 42 notes per octave? We can do that.