# Ensoniq ESQ-1, ESQ-M, SQ-80 These synthesizers form a "family". The ESQ-1 was the original keyboard version, the ESQ-M is the rack version and the SQ-80 is essentially an enhanced ESQ-1. Sound generation: The ESQ-1 family is a hybrid of digital and analog. The "oscillators" are digital, as is much of the rest of the synth. The filters and final DCA stage are analog, courtesy of the Curtis chips common in many synths of this vintage (1986). The unit has eight "voices". Each voice consists of three oscillators (each with its own amplifier), a single filter, a common amplifier, and a modulator pool of three LFOs and four envelope generators. With the exception of the envelope generator hardwired to the final amplifier stage, the modulator pool can be routed to any destination, the source of most of the unit's versatility. The oscillators use single cycle (with some exceptions in the SQ-80, stay tuned) digitized waveforms. Those that are obtained from samples are multisampled across the keyboard. The ESQ-1 and ESQ-M have a pallette of 32 waveforms. The SQ-80 has these same 32, plus an additional 43. A few of these 43 are multi-cycle samples. Waveforms include the bread and butter squares, saws, pulse, etc. from analog subtractive synthesis, plus sampled sounds including pianos, basses, woodwinds, as well as waveforms derived from complex synthesis techniques like the Karplus-Strong plucked string algorithm, etc. Patches may be used polyphonically or monophonically; portamento is supported (called "glide"). Any patch may be split and/or layered with anmy other patch. The ESQ-1 architecture does not distinguish between a "normal" mode and a "split" mode like many synths of its vintage. It merely maintains pointers to other patches in memory. 40 patches are stored in local memory, a cartridge port allows two banks of 40 each to be accessed. Some third party carts support multiple banks, the max I have seen is 320 in one cartridge, but only 80 at a time can be used. Cartridges use EEPROM chips not RAM, so no battery is needed to hold the data. Each patch is actually mono, but can be panned between the two outputs. Panning is at the *patch* level, so that patches can be made to move across the stereo soundstage under control of an LFO, enevelope, velocity, mod wheel, what have you. The unit is multitimbral, using dynamic voice allocation to assign the eight voices as needed. The sequencer track pages are used to control the multitimbral part assignments. Keyboard: The ESQ-1 and SQ-80 both have a 61 key keyboard. Both are velocity sensitive. The SQ-80 keyboard also has aftertouch and can generate either polyphonic/key pressure or mono/channel pressure. All three units respond to both types of aftertouch via MIDI. Bend and mod wheel plus control voltage (expression) and sustain pedals are supported. One external MIDI controller can be used as a modulator as well. Sequencer: The ESQ-1 and SQ-80 have an onboard eight track sequencer that is very easy to use and was at its time state of the art for an onboard unit. The original ESQ-1 stored 2400 events, later expansions were offered to allow 10,000 or 20,000 event storage. The SQ-80 stores 20,000 events and no expansion is possible. Sequences are stored in two levels, "sequences" which chain into "songs" (similar to how most drum machines chain patterns into songs). The ESQ-1 has 10 songs/30 sequences maximum, the SQ-80 allows twice as many (20/60). Sequence data is interchangeable at the individual sequence level and bulk dumps from ESQ-1 to SQ-80. Dumps from the SQ-80 to the ESQ-1 cannot be done. All units have a cassette tape interface for data storage, which doubles as an FSK synch connection for the sequencer. The SQ-80 also has a 3.5" DSDD floppy drive for faster data access. The drive can be used to store system exclusive data up to 64K bytes in length. In addition, there are hardware and software hooks to be able to save data off to the disk drive of an Ensoniq Mirage. Sequences may be edited via overdub or by step editing. Controllers may be stripped but there is no single event editing of anything but note data. Program changes, tempo changes, time signature changes and volume changes may be programmed into the sequence but can only occur on sequence boundaries (essentially on any bar line). A very useful feature is that all sequence changes may be auditioned before any existing data actually is modified. Sound: The sound of the ESQs is halfway between an analog synth and early digital machines (like the DX7). Although some sampled waveforms are included, the sounds created with them are not overly realistic compared to more modern sample-based machines. Many people describe its sound as "grainy", although it seems to be free of the high frequency aliasing artifcats of the early FM and L/A machines. The modulation pool and resonant filters make this unit well adapted to classic synthesizer textures. The SQ-80's additional waveforms include attack samples and acyclic loops which allow it to produce some sounds similar to the Roland D-50. It also includes some drum samples, but the "kit" is limited to kick, snare, closed hi-hat and toms. These samples are, however, quite useable and can be processed through the amplifers and filter to create numerous "synth drum" timbres. The SQ-80 can reproduce any ESQ-1 or ESQ-M patch. SQ-80 patches using the additional waveforms not found on the ESQ-1 will not sound correct on the ESQ-1 or ESQ-M. MIDI: The MIDI implementation is quite good. All front panel functions can be controlled by system exclusive. The units send and recieve on any MIDI channel, in fact these channels need not be the same. A special mode for use with guitar controllers is included. The ESQ-1 has MIDI IN and OUT only, the ESQ-M and SQ-80 also have THRU. Summary: Three years before Korg proclaimed the M1 a "workstation", the ESQ-1 was one. It is still a good choice for someone looking for a self-contained synth/sequencer package. The SQ-80 is worth the extra $$ for the disk drive, aftertouch keyboard and extra waveforms if these are of interest. The ESQ-M module is not as common (it sold poorly when in production) since many users were not as enamored with the ESQ-1 sounds as with the built-in sequencer. The sequencer itself still holds up well against some other on-board units in competing machines (I'm thinking specifically of the Korg M1 and Roland D20 here). The sound is somewhat generic, in that it doesn't have an obvious "signature" the way the DX7 and D50 did. However, it has an architecture well suited to being able to create a wider range of sounds than other synths of its vintage. In that sense, it's of more interest to folks willing to learn to program it as opposed to just calling up some hot presets. There is still a reasonable amount of third party support for the ESQ-1, you can still buy patch sets, get memory cartridges, etc. although that support is bound to dwindle in the coming years. There is a good amount of public domain support for the machine, including plenty of patches and patch librarian software for a number of computers. Brian Rost rost@rgb.dec.com