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Ensoniq ESQ1 Polysynth

The Mirage people announce a synth that uses analogue and digital technology, throws in a multitrack sequencer, and costs just over £1000. Paul Wiffen checks it out.

Having given musicians the first truly affordable sampling keyboard, Ensoniq have taken a step sideways to embrace the synthesiser. The result is the ESQ1, an instrument flexible enough to become the nerve-centre of a complex electronic music system.

Curious company, Ensoniq. Curious, and clever with it. Eighteen months ago, when everybody was looking to the established manufacturers to come out with a sampling keyboard within range of the average musician, they came out of nowhere with the Mirage. And now that all the other major names have finally got their samplers out, the people from Pennsylvania are already moving into other areas.

Specifically, their latest machines cater for both the traditional keyboard player (with the weighted keyboard and sampled accuracy of the Ensoniq Piano) and the thoroughly modern synthesist via the instrument under scrutiny here.

The ESQ1 is an eight-voice digital synthesiser which also encompasses a versatile multitrack sequencer able to sequence not only internal voices, but also a considerable number of external devices via MIDI. In fact, so complete is its MIDI implementation, you could even use the ESQ1 as a master keyboard, making it the centre of a complete MIDI system.

The first thing in any player's mind when buying a synthesiser will always be the sound of the instrument, so let's take a look at the ESQ1's voicing to start with.

Each of the eight voices has no less than three oscillators - more than any other synth under £2000.

Waveforms for the ESQ1 are drawn from a wider range than previously possible on a conventional synthesiser. In addition to the conventional waveforms bequeathed to us by the analogue synth (ramp, triangle, square, pulse), there are waveforms created by digital calculation to contain certain specific harmonic series. And more excitingly, there are waveforms which have samples of real sounds as their source. Not a new idea, this, but on the ESQ1, the waveforms are derived from multi-samples taken at the point where the sample is brightest, so you have the maximum harmonic content that appears in the sample. This section is then looped so that it sustains indefinitely, as waveforms normally do on conventional synths.

Now, one of the problems musicians and programmers experience with samplers lies in sustaining a sample indefinitely - unless you manage to get a good loop on it. With the ESQ1, these problems disappear, as Ensoniq have already looped the machine's multisample waveforms for you.

All you need do is adjust the filter and amplifiers to imitate the changes in loudness and brightness that characterise the original instrument. Even here, Ensoniq have done some of the work for you. The ESQ1 has not only a waveform entitled 'Piano', but also a factory patch of the same name which uses that waveform filtered and enveloped in such a way as to recreate the timbre of a piano. Using a footpedal, you can sustain this sound exactly as you would with a conventional piano. So, we have the realism of a sampled piano sound with the immediacy of a synth preset (no waiting for disks to load here). What's more, the multi-sampled piano waveform is still available to be used singly, doubled, or in conjunction with up to two other waveforms in the other patches on the machine.

Intriguing though this sampling-meets-synthesis concept is, it shouldn't detract from those ESQ1 waveforms which are entirely synthetic, rather than taken from acoustic sources. Because as it turns out, many of the more exciting patches are made entirely from the synthetic waveforms.

Ensoniq divide their waveforms into five categories. First come 'Classic Synth Waveforms', which include sawtooth, sine, square, pulse, and three noise waveforms. Second are the Sampled Waveforms such as bass, piano, reed, organ, two voices and kick. The third section is created by Additive Synthesis, and the manual actually tells you which harmonics are present in each of the three waveforms in this group. Formant Waveforms come next: these are multi-sampled with a resonant peak which stays around the same frequency (given in the manual) wherever you play on the keyboard. Last come the Sound Limited Waveforms, which are versions of some of the other waveforms with limited bandwidth.

Personal Wiffen favourites are 'Pulse' among the analogue (though you can't modulate the pulse width), 'Bass' among the samples, which has a sharp, realistic top end while retaining plenty of power lower down, and all the Formants (I couldn't decide which one of these five was best for vocal sounds - they all sound pretty good). The band-limited patches are great for beefing up the lower end of sounds, while those created using additive synthesis are certainly unusual, and especially interesting played through a slowly closing filter.

But one of the best things about the ESQ1 is the scope it gives you for experimenting with different combinations of waveforms from different origins. After a few minutes' twiddling, you can discover that, for example, an analogue waveform can make the piano waveform sound more authentic, or that a sampled bass waveform can be the basis for a great synth sound. Fascinating stuff, and addictive, too.

Once you've decided on your combination of analogue, digital and sampled waveforms for each of the Ensoniq's three oscillators, you can decide how you want to process them.

Before getting into the filters and envelopes, there are several modulation facilities available. These include a feature I always thought had faded away with the last of the great analogue synths - Sync. For those of you too young to remember the Prophet 5 or Moog Prodigy, Sync is a means of forcing a synth oscillator to restart its cycle (ie. the oscillation that produces the pitch and harmonic content) each time the controlling oscillator begins a new cycle.

This can produce some excellent beefy, distorted sounds, especially if the oscillator being controlled is shifted in pitch by an envelope or glide function as well.

On the ESQ1, the ability to use this facility with multi-sampled waveforms (which have never been 'Syncable' before) kept me occupied for some considerable while, and gave rise to some fine, distinctive sounds.

Another interesting modulation option is Amplitude Modulation. This doesn't use the same process as Yamaha's FM, but the sideband frequencies produced by Ensoniq's process are similar, and the sounds that result have much in common with the electric piano/bell-type sounds that the DX range is so good at generating. And as you're starting with more complex waveforms than you would on a DX, you build up more complex sounds very quickly.

Once you've finished messing around with the harmonic content of the oscillators, you can set a different loudness envelope for each one, if that's what you want. The ESQ1 actually gives you control of the relative mix in real-time, so you can start with, say, just the first oscillator with sharp attack, bring the second in more slowly, and then just as both are dying away, bring up the third oscillator to replace them. The envelopes available to you are more versatile than standard ADSRs, too, so there's plenty of flexibility in the way you combine the different sounds emanating from the oscillators. Imagine, for example, a brassy attack (from a ramp wave) becoming a sharp digital sustain fading into a piano decay... And all this timbre change possible before you even start to use the filter and its associated envelope.

The filter itself (there's one for each voice) is the classic four-pole device which has remained little changed from the days of the earliest analogue synths. Besides the standard Cutoff frequency and Q controls, there are Keyboard Tracking and Envelope Amount parameters.

The filter can be controlled by the same versatile type of envelope mentioned above - the sort of envelope which really deserves something of a closer look. Briefly, the ESQ1's envelopes use the Time and Level parameters which are becoming more and more common these days, as they allow complex envelope shapes (in addition to the more standard ADSR shapes) to be created. Each phase of the envelope is programmed by setting a Level, and then a Time which the envelope takes to reach that level.

In ADSR terms, Level 1 would be the peak and Level 3 the sustain level. As the envelope has to return to zero to finish, Level 4 must always be zero. The four Time parameters can roughly be described as Attack (Time 1), Initial Delay (Time 2), Second Delay (Time 3), and Release (Time 4). However, it's possible for these parameters to be set in such a way that they go beyond these descriptions. If, for instance, you set Level 3 above Level 2, Time 3 becomes more like a Second Attack than a Second Delay.

Add to this the fact that all values can be negative as well as positive (useful for controlling the filter, for example), and you begin to see the potential of this system, though it isn't quite as flexible as the eight-stage format employed by Casio in their CZ range.

All envelopes can also be affected by the velocity with which you hit the Ensoniq's keys, which can control not only peak level (and all other levels in proportion) but also the attack time (ie. how much Time 1 varies from the programmable amount). In addition to this, a Keyboard Delay Scaling feature allows you to shorten the overall time the envelope lasts as you go further up the keyboard. This imitates the nature of plucked or hammered acoustic keyboard sounds, which tend to be of shorter duration the higher up the keyboard you go.

There are actually four envelopes per voice on the ESQ1. The first three are each assigned to their respective oscillators, the fourth to the overall output level. The filter can be controlled by any of the four envelopes, but sadly, it has no separate envelope of its own.

Including the four envelopes, there are 15 possible modulation sources on the ESQ1. These include three LFOs, various velocity and keyboard tracking curves, plus wheels, pedal or any MIDI controller (including pressure). These 15 sources are always available to modify the pitch and level of the oscillators, the filter cutoff or the stereo pan position.

The modulation sources include the most versatile LFOs I've ever seen, with two levels of effect and delay (rise time), plus the ability for the LFO to be further modulated by another source - even itself, if you're feeling experimental. And in case all this flexibility leaves you feeling a little confused, the manual shows you how to create standard modulations like wheel control of vibrato.

Staying with the manual, it's worth pointing out that unlike the documentation that came with initial Mirages, the manual for the ESQ1 covers all aspects of the machine in great detail, with some fine explanatory sections just in case anything isn't immediately obvious. In this respect, the latest Ensoniq manual is more like the Advanced Sampling Guide for the Mirage, but for the impatient, it also contains two brief sections titled 'Getting Started' and 'Getting at the Sounds'.

To be fair, though, the manual is something you may not need to look at for a while after you've bought an ESQ1. Because unlike so many modern synths, the new Ensoniq has a programming layout that's so easy to get to grips with, it almost invites you to delve deeper.

Whole groups of parameters - referred to as pages - are called up into a large 80-character LED display, and can then quickly be accessed by pressing the closest button.

The values then shown can be changed using either a slider or up/down buttons - depending on whether you want drastic change or fine control. So each page allows easy access between the related parameters, and saves you darting about between individual parameters 'blind', the way so many digital access systems force you to. It's not as useful (or usable) as good ol' knobs and switches, but it's a step in the right direction.

The Ensoniq's display is one reason for the machine's ease of use, mostly because of the sheer amount of information it can convey at any one time. One display, for example, caters for an entire page-worth of standard MIDI features such as Channel Assignment, Mode, Controller, and Program Change Enable, plus additional features such as Overflow Mode and Multi-Mode.

Both of the latter are excellent facilities, but neither is quite the innovation Ensoniq claim. Overflow Mode (where any extra notes played on the ESQ1's keyboard or sequencer which the internal voicing can't cope with are 'requested' via MIDI so you can hook up a second ESQ1 and have a 16-voice system) has been available on the Prophet 2000 for nine months now, while Multi-Mode is similar to the way the Casio CZ5000 sequencer assigns various MIDI channels to its internal sounds and external slave synths.

Still, it's good to see companies like Ensoniq continuously looking for ways to increase the flexibility of MIDI, rather than just implementing the basics and leaving it at that.

"Specification: There are 15 modulation sources, including four envelopes, three LFOs, and various velocity and keyboard tracking curves."

Another page worth its weight in gold is Split/Layer. This allows you to save within the program the fact that two patches are used, and these can then be either doubled to create a layered effect, or arranged so you have two different patches on each side of the assigned split point.

In total, the ESQ1 holds 40 different programs internally, arranged in four separate banks of 10 each. That isn't too many by today's standards, but take heart in the fact that ten named programs can be scanned in the display at any one time, and that each can be chosen in the same way parameters are selected when programming. Another 80 programs can be accessed (in two sets of 40) on the E2PROM Cartridge, and these can also be displayed in banks of 10 before selection. So for live performance work, you've got instant access to 120 programs - so long as a cartridge is in the slot.

Less instantly impressive than the synthesiser section - though no less useful in the long run - is the ESQ1's built-in sequencer. It's a comprehensive beast as integral recorders go, and you can use it in two different ways.

The first option allows you to sequence just internal voices multi-timbrally. In other words, each track can have a different sound on it, so entire pieces of music, of up to eight parts, can be recorded. The second option allows you to sequence eight external synthesisers to the extent of their polyphonic capability, by assigning each of them to a different MIDI channel.

As a third alternative, though, you can use both methods of working in conjunction with each other, using both internal and external synth voices. For example, you could make tracks 1 and 2 play just internal programs, track 3 an external synth, 4 and 5 doubled on both the ESQ1 and other keyboards, and so on. You're limited to eight voices on the ESQ1 itself, but because of the clever dynamic allocation implemented on the machine, those eight voices are always available to play any sound - so provided they're not being used at that instant anywhere else, you can have up to eight notes on each internal track.

Because of its portability, it's conceivable many musicians will use the ESQ1 as a songwriting tool, and then augment it with other synths in the recording studio to put their original performance on tape, while retaining complete freedom over the sounds they're using. Luckily, the sequencer's assignment potential is wide enough to make this possible.

The sequencer can store up to ten songs, each identified by a name, and these can be made up from 30 sequences. Now, you may find, once you start to put your entire live set into the machine, that the Ensoniq's internal memory of 2400 notes doesn't get you past the third song. Don't worry. A cheap cartridge is easily inserted (and held in place by screws) to expand this capacity to over 10,000 notes.

Operating the ESQ1's sequencer is simple enough. All you do is enter the track you want while the required sound is currently selected. This automatically assigns that sound to the track, and you're then free to record your part.

If you select a cartridge sound, its name is displayed in the track space until you remove the cartridge, whereupon the display informs you that you need to re-insert the cartridge before that track will play. Alternatively, you can just go to the MIDI/Mix page and assign that track to both Record and Playback on a particular MIDI channel, simply by entering the appropriate number.

Once a track is recorded, you can edit it in several ways. First there are standard MIDI sequencer functions like Transposition and Quantisation (otherwise known as Auto-correct). The Quantisation bit is particularly cunning, allowing you to select a resolution between quarter-notes and 32nd-note triplets, listen to the corrected part, and then decide if you want to keep the new version or the original. This way of quantising 'after the event' rather than during recording is definitely worthwhile, as it allows you to keep the human element in a performance without having to put up with human fallibility (which I specialise in).

Step-time recording - so often neglected by US manufacturers - is also available on the ESQ1's sequencer. This method allows you to be analytical in your composition, and also to program things you find tricky (or just plain impossible) to play. Step size can be from quarter-notes to 32nd-note triplets, as with the quantisation, and the readout shows the bar number, the beat number and the clock number you're currently on, so you don't get lost.

If you prefer a more tape machine-like way of recording difficult sections and correcting mistakes, the sequencer also features Punch In and Punch Out facilities, enabling you to 'drop-in' small sections in your own good time.

There are some more advanced editing functions available, too. For example, you can use Remove Controllers to get rid of any unwanted MIDI controller data. This is particularly useful in conjunction with something like a DX7, which sends out pressure data whether you're using it or not. This would normally use up even the 32K of expanded sequencer memory ridiculously quickly, so it's as well to have a feature whereby you can remove it if it isn't being used.

Other useful edit functions include Merging Tracks (what we'd call 'bouncing together' in the recording studio) and Copying Tracks, which allow you to move recorded parts around and arrange them in the best format. To build sequences into longer sections (thereby freeing sequence locations), you can use Append, which tacks one sequence onto the end of another. Alternatively, you can extend or truncate a sequence to make room for extra bars, or lose some that are less than perfect. And the MIDI/Mix page allows you to adjust the relative levels of your tracks.

When you have your sequences together, you can start to build them up into songs. Each step of a song can be accessed in the Song Edit page, and each one can be Transposed, Repeated, or Deleted. You can insert extra sequences at any time, and you can move backwards and forwards within the song to facilitate this.

You can also go straight to any point in a song using the Song Locate page, and see what tempo and time signature have been used. The 'Goto' parameter jumps automatically to the step you want.

Synchronisation to the outside world is possible via a variety of options. There's tape sync for the recording studio, and MIDI for drum machines and other relative MIDI devices or even SMPTE-to-MIDI syncing.

The last facility is particularly useful, as the ESQ1 both sends and receives song position pointers via MIDI. Using the Autolocate controls, you can start playback of all MIDI devices with song pointers implemented from any point in the song. Even more importantly, the ESQ1 (in conjunction with a SMPTE-to-MIDI converter like the Roland SBX80 or Fostex 4050) can be made to autolocate alongside a tape machine to start playback automatically at the same point as the tape. The great advantage of this is that parts recorded on the ESQ1's sequencer needn't be recorded onto multitrack, but played back from the sequencer into the final mix. This frees tracks on tape for other instruments, vocals, and so on which can't be sequenced.

The sequencer can also perform a different role. Taking advantage of the fact that the ESQ1 will store patch numbers and transmit them via MIDI even if a sequence has not been recorded, you can hit a sequence number and have up to eight different MIDI patch changes sent to different synths and other MIDI devices like signal processors, setting them up for the next song even if you don't intend to sequence them. Or you can record these program changes as the end of a song in readiness for the next piece. Or why not have the ESQ1 change programs for you on the keyboards you're playing, or while the others are being sequenced?

This facility, together with the flexible MIDI implementation we looked at earlier, means the ESQ1 can readily function as the central controller of an entire MIDI system, especially if you're on the sort of budget where a master MIDI keyboard looks expensive for something that makes no noise itself.

If you own a DX7, you might do your playing and sequence recording from that, to take advantage of the key pressure which the ESQ1 can record and playback-even though it can't generate pressure itself.


Ensoniq ESQ1 Digital Synthesiser/Sequencer

61 note C-to-C, velocity-sensitive

Sound Source
3 oscillators per voice using analogue, digital and sampled waveforms

8-voice polyphonic, Single or Split/Layer modes; monophonic option

40 RAM memories for user-programmed sounds, shipped containing factory presets. 2400 notes (8K) of sequencer storage

External Storage
E2PROM Cartridge holds 80 programs in two master banks, VCP Voice Cartridge holds 80 factory-programmed sounds, SQX10 Sequencer Expander cartridge expands memory to over 10,000 notes (32K)

80-character fluorescent with 10 'zones'

Left (Mono) and Right stereo Audio Outs, CV/Pedal In for SW1 optional foot switch, Tape Storage In and Out, MIDI In and Out

Price £1,080 including VAT

More from Ensoniq UK, (Contact Details)

If you own a Mirage, you can save and load ESQ1 programs and sequences to Mirage disks via MIDI. This is faster and easier than the tape storage procedure that the ESQ1 also provides, but a bigger advantage with Mirage saving is that you can keep all your ESQ1 programs, sequences and MIDI controller information on one disk.

All in all, it's difficult for me to fault the ESQ1. Yes, I wish they'd put either a MIDI Thru socket on the back, or at least the switch between Out and Thru that the Mirage has, just in case you don't want to use the ESQ1 as your main instrument. And yes, an entirely separate envelope for the filter would have been nice.

But these criticisms seem trivial stacked alongside the ESQ1's good points.

As a synthesiser, it's able to recreate a wide range of 'standard' synth sounds, and create new ones by the innovative way it combines analogue, digital and sampled waveforms. Its voice processing is nothing if not comprehensive, and its programming system is one of the modern synth industry's most friendly.

As a sequencer, it's encouragingly quick and easy to use, and most important, it doesn't do anything which could destroy unrepeatable sequences.

And as the centre of a modern electronic music system - live or in the studio - it has a MIDI implementation so flexible that, whether you're playing your other MIDI instruments directly or sequencing them, it's difficult to imagine a setup that the ESQ1 couldn't cope with.

If this was the latest instrument from an established synthesiser company, it would be worthy of high praise. But as the first synth from a company that hasn't been in existence for more than a couple of years, the ESQ1 is a revelation, and a hugely heartening one at that. Really, an outstanding bargain.

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Electronics & Music Maker - Copyright: Music Maker Publications (UK), Future Publishing.


Electronics & Music Maker - Aug 1986

Scanned by: Stewart Lawler

Gear in this article:

Synthesizer > Ensoniq > ESQ1

Gear Tags:

Analog/Digital Hybrid Synth

Review by Paul Wiffen

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