The Ensoniq ESQ-1 is a 61-key, velocity sensitive, eight-note polyphonic and multitimbral synthesizer released by Ensoniq in 1985. It was marketed as a "digital wave synthesizer" but is actually an early music workstation. Although its voice generation is typically subtrative in much the same fashion as most analog synthesizer that preceded it, its oscillators are neither voltage nor digitally controlled, but true digital oscillators, provided by a custom Ensoniq wavetable chip. The signal path includes analog resonant low-pass filters and an analog amplifier.

The synth also features a fully functional, 8-track MIDI sequencer that can run either its internal sounds, external MIDI equipment, or both, with a capacity of 2,400 notes (expandable via cartridges). It provides quantization, step-editing, primitive forms of copy/paste editing, and can be synchronized with external MIDI or tape-in clock.

The Ensoniq ESQ-1 has a particularly easy user interface, especially for a feature-filled digital synthesizer of the time and a multitimbral workstation/sequencer, by way of a large 40-character x 2-line display, ten softkeys (5 above and 5 below display), and system of all dedicated direct-access buttons per ten-parameter/patch page, meaning there is no "menu diving" within hierarchical series of sub-pages whatsoever.

The Ensoniq ESQ-1 can store 40 rewritable sound patches internally, and features a rewritable EEPROM or fixed ROM cartridge slot for access to 80 additional patches. Notably, the sound chip at the core of the synth, the 5503 Digital Oscillator Chip (DOC), is a brainchild of Robert Yannes, father of the popular Commodore SID chip. The chip was previously used in Ensoniq's Mirage sampler, later in ESQ-1's enhanced successor SQ-80, as well as the Apple IIGS personal computer.

The Ensoniq ESQ 1 is actually two powerful devices. An eight voice, poly-timbral Digital Synthesizer, and a flexible eight-track MIDI Sequencer built into one package. Whether you plan to use the ESQ 1 by itself, or as the master controller in your MIDI set-up, you'll find that it is a tool of enormous power and versatility for performing, recording and composing music. The Synthesizer With three Digital Wave Oscillators per voice, thirty-two sampled and synthetic Waveforms to choose from, and 15 routable Modulation sources, the ESQ 1 is capable of producing a wide variety of rich, complex sounds. The five-octave, velocity sensitive keyboard can be split for different sounds on each half, layered for two sounds playing together, or even programmed for a Split/Layer mode in which two totally different pairs of sounds play on each keyboard half. Forty Programs, or 'patches', are stored in the Internal Memory, with another eighty available on an external, plug-in Cartridge, giving you 120 sounds to select from instantly. In addition, the eighty-character fluorescent Display shows the names of ten programs at a time, making it easy to quickly scroll through all the sounds, to find the one you want. These programs can be played as is, or they can be modified to suit your taste and then renamed and stored, either in the Internal or the Cartridge Memory. Editing of ail programs, sequences, and 'global' functions (such as Tuning, Bend Range, etc.) is handled from the informative, 'Page-driven' Display which shows at a glance all the parameters associated with a selected function. be Audio outputs are provided for true stereo, as well as a mono output. Programs can be panned continuously between the left and right channels. The ESQ 1 also has an Amplitude Modulation (AM) mode which can produce bell and ring-modulator type effects, and a Sync mode for hard sync effects.

The Sequencer

The built-in Sequencer can record and play back 2400 notes (expandable to 10,000 with the optional Sequencer Expander Cartridge). It will store 30 different Sequences, which can be combined into 10 Songs. Sequences and Songs can be saved to tape or via MIDI to diskette using an ENSONIQ Mirage Digital Sampling Keyboard Mirage Digital Multi-Sampler or it is a full eight track MIDI Sequencer, capable of playing eight separate polyphonic Tracks internally, each with its own sound; or sequencing eight separate MIDI devices at once; or both. Each Track has an adjustable Output level, a MIDI channel, a Program number, and a MIDI Status (LOCAL, MIDI or BOTH).  In addition to its own internal clock, the Sequencer can sync to the clock output of another MIDI device (such as a Drum Machine or another Sequencer), or record a sync track to audio tape, and sync to that, to get the most out of any multi-track set-up. The ESQ1 1's Edit functions allow you to easily modify Songs, Sequences, Tracks, or individual Events in a variety of ways. Quantization (or Auto-Correct) is available to make each performance letter-perfect. The Auto-Locate controls give you quick access to any point in a Sequence or Song, and you can "Punch in" (or out of) a Track, just like on a tape deck. However, each time you record over any part of a Track, the ESQ 1 gives you the chance to listen to the new Track, and the original, before you decide which one to keep. Try that on a tape deck.

Control

In short, the ESQ 1 employs computer technology to combine a state-of-the-art Digital Synthesizer with a powerful MIDI Sequencer in one manageable, easy to use instrument, to give you a whole new level of control over your music. Getting great sounds out of the ESQ 1 is simple -- just read the sections in the manual entitled Getting Started and Getting at the Sounds, plug it in and play. Learning to take full advantage of its tremendous power and versatility will take a bit longer, but you'll find that it's worth the trip.