Korg DW-8000

DW-8000
Manufacturer Korg
Dates 1985 - 1987
Technical specifications
Polyphony 8
Timbrality 1
Oscillator DWGS × 2 voice
Synthesis type Analog/digital hybrid using subtractive synthesis
Filter 24 dB VCF (analog)
Storage memory 64
Effects Digital delay
Input/output
Keyboard 61-key mono-pressure sensitive
Left-hand control Joystick
External control MIDI

The Korg DW-8000 synthesizer was an eight note polyphonic hybrid digital-analog synthesizer 61-note keyboard instrument released in 1985. Eight note polyphony means up to eight notes could be played at a time. By the time of its launch Korg had already begun a common trend in 1980s synthesizer design: using numerical codes to access or change parameters (synth "voice", tone, etc) as with the Korg Poly-800. This was a move away from the heavily laden, complex control panels of earlier designs.

A more unusual feature of the instrument for the time was the use of single-cycle digital waveforms as the basic building block of sound synthesis, and the inclusion of a digital delay effect. This latter feature was one significant factor in the relative success of the DW-8000 compared to the DW-6000 released the same year. It was released along with the cheaper model, the Korg DW-6000 synthesizer.

Physical characteristics

Physically, the instrument used a 61-note synthesizer action keyboard. "Synthesizer action" means that it did not have weighted or semi-weighted keys, a common feature on stage pianos marketed at pianists. The DW-8000 keys were velocity sensitive. As such, a light press triggered a quieter sound and a hard press triggered a louder sound. As well, its keys could sense channel-pressure aftertouch as well. Aftertouch is the placing of pressure on keys after the initial striking or pressing of the keys. On a digital keyboard with aftertouch sensitivity, when the performer continues to press the keys, the aftertouch sensors send a message to the synth module; depending on the programming of the synth patch and/or the settings selected by the performer, aftertouch can trigger a digital effect (e.g., vibrato) or a change in the timbre (tone colour). The keyboard sents aftertouch messages via MIDI if required.

A four-way joystick was provided to control low-frequency oscillation (LFO) modulation as well as pitch bending. Pulling the joystick bender towards you also allowed control over voltage-controlled filter (VCF) as well. Around the back panel are jacks for headphones, stereo line out (to plug into a keyboard amplifier, PA system, mixing board, etc.), pedal inputs for damper, portamento and "program up" are provided. Also available are two sockets for tape recorder interface to facilitate offline patch backup and storage of sounds and other data. Electrical power was supplied via a two-pin IEC C9-type connection cable rather than the rather more ubiquitous C13 type, which can potentially be a source of frustration if lost.

Patch storage and backup

The instrument had 64 memories which could be backed up to cassette tape in similar fashion to that used for home computers of the time. This system could be prone to error or mishap as the availability of the “verify” feature for the tape backup system can attest to. The instrument did however possess the capability in MIDI to allow sys-ex transfer provided you had another DW-8000 or a computer with suitable software that can send the MIDI dump request message to it. A modern and more reliable alternative to the cassette tape interface is the portable CD player with wave files saved on disc. An optional accessory was the MEX-8000, a hardware device which could provide extra storage to the user.

DWGS synthesis

As basic material, sixteen digital wave cycle waveforms were available to the user through a system Korg called DWGS for Digital Waveform Generator System. The DWGS system can be thought of as an early sample playback system where only extremely short, single cycle waveforms are stored on four 256 Kilobit ROM chips, played back through the two digital oscillators and processed by relatively familiar subtractive synthesis facilities. The waveforms themselves were the usual staple sine, sawtooth, and pulse waveforms, but more unusually featured waveforms such as emulations (imitations) of acoustic piano and saxophone. To aid the user in appropriate selection, each of the sixteen wave samples are printed on the right hand end of the operating panel along with the parameter reference below. Any two of the digitised waveforms could be used by the two digital oscillators provided. A noise source could be added separately to add further timbre or tone colour.

Oscillator modes

The synthesizer could be used in two polyphonic modes (polyphonic means that more than one note can be played at the same time) and two monophonic modes (monophonic means only one note can be played at a time). The latter monophonic modes are worthy of examination on account of sounds they can generate. Each of the two monophonic modes arranged the oscillators into a single note stack of slightly detuned oscillators. Use of these two monophonic modes changes the character of any given patch quite considerably, generally imbuing it with what could best be described as a powerful or "fat" sound.

Analogue VCA and VCF stages

Whilst the source sounds were digital, the subsequent major sound shaping stages consisted of an analogue variable-gain amplifier (VGA) enveloper using six stages and similar arrangement also for the analogue filter. The filter is unmistakably analogue and can be pushed into self-oscillation using the filter-resonance parameter. Further modulation of the sound could be applied using the single LFO which could either modulate oscillators to produce vibrato effect or the filter, or even both at the same time should such be desired. A significant creative limitation of the DW-8000 architecture was that the user could not control the LFO depth with respect to each oscillator, as they were both modulated in common.

Digital delay effects

The final key part of the architecture was the digital delay section, which provided an effect unit that could be applied to the sound. As the rest of the synthesizer architecture up to this point in the sound chain was analogue, the signal had to be converted back to a digital signal so that it could have the effect applied. This fact is evident in the increased noise when using the delay effect. Despite this, it was a flexible digital delay that gave times ranging from 2 to 512 milliseconds in length. Delay effects are similar to reverb. Added to this was a modulation depth parameter so the user could create chorus and flanging effects as well as delay.

Arpeggiator section

In 1985 synthesizers with built-in sequencing facilities were quite rare; however, the DW-8000 did have a 64-note arpeggiator section. An arpeggiator automatically plays the notes of chords in arpeggios (an arpeggio is playing the notes of a chord one after the other, instead of all at the same time) just from the user pressing a single note. The 64-note memory could be especially useful when the arpeggiator was set to its “assignable” mode. This allowed the arpeggiator to loop round any number of notes up to 64 that the user added to the arpeggio. The arpeggiator can be set to latch so that the sequence continues to play after the user releases the keys, or un-latched; then the sequence will immediately stop when keys are released. A facility to make the arpeggio span one or two octaves, or even the full keyboard can be selected. A tempo slider sits immediately to the left of the arpeggiator controls to control the speed of the arpeggiator sequence.

Historical assessment

The DW-8000 in itself cannot be seen as a huge milestone or breakthrough product. But the hybrid architecture of digital waves partnered with subtractive synthesis was to become an important approach used in Korg keyboards during the second half of the 1980s. Other manufacturers were developing instruments using similar ingredients of samples and effects, though still using traditional subtractive synthesis with better technology. The Korg DW-8000 was not multitimbral and would therefore not fare well in the market that only two years later would produce both the Roland D-50 and MT-32, which used samples of real attack transients to create increased realism in their imitations of real acoustic instrument sounds. The MT32 also brought multitimbral capabilities, with relatively high quality effects. Korg took longer to find the winning combination, but by the end of the decade had achieved considerable success with their M1 workstation keyboard that included a few old DWGS waves.

Notable users

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