Synthesizer

Overview

A synthesizer is an electronic instrument that generates sound from scratch rather than amplifying a vibrating string or membrane. Voltage-controlled circuits create waveforms, shape their harmonic content with filters, and control their loudness over time, all steered by the keyboard and panel controls. The hybrid design described here pairs analog signal-path circuitry, prized for its character, with digital control and modulation, giving eight voices of subtractive synthesis playable from a 61-key keyboard.

Each note is built by a voice on the Voice Board Assembly, which follows the classic subtractive chain: analog VCO chips generate raw oscillator waveforms, VCF chips filter them to sculpt timbre, and VCA chips set the amplitude envelope. A DSP system-on-chip handles modulation and digital effects, and DACs render the result to analog audio. The keys themselves live in the Keyboard Assembly, where conductive rubber contacts under each key are read by a scan board that reports which notes are held and how hard, driving the voice engine.

How it works

The player shapes the sound through the Control Panel Assembly, a dense array of knobs, faders, buttons and a panel controller that map directly to synthesis parameters such as filter cutoff, resonance and envelope times. Mounted alongside are the Pitch Wheel and Modulation Wheel for expressive bends and vibrato. Patches and the current state are shown on the Display Assembly. Audio leaves through the Audio Output Board, which provides line outputs, a headphone amp and MIDI, USB and CV/gate jacks, so the synthesizer can be sequenced by a computer or wired to other analog gear. All of this is housed in the Chassis Assembly, a metal-and-wood enclosure with end cheeks that carries the boards, keybed and panel.