Korg Wavestation A/D
Digital Synth Module
The Wavestation A/D takes the digital and vector synthesis systems of its popular parent and adds analogue inputs. Simon Trask reports on the continued evolution of one of today's most flexible synths.
If the M1 brought Korg mainstream popularity, the Wavestation brought them credibility, combining the old style flexibility with current technology - now it has even more to offer.
Back in 1990, there emerged a synth which turned its back on the familiar terrain of sample-based synthesis and headed straight for waveform heaven instead. That instrument - Korg's Wavestation - offered musicians an opportunity to (re)discover creative synthesis using abstract sound material in place of recognisable instrumental samples. However, unlike the analogue synthesisers of old, with their small number of waveforms, the Wavestation provided 365 digitally-stored waves covering a wide range of timbres, suitable for use both as sounds in their own right and as starting points for synthesis. It was characteristic of an instrument which embraced new possibilities at the same time as it harked back to old values.
In addition to a familiar subtractive synthesis-type programming environment - oscillator, filter, amplifier, amplitude envelope, ENV1, LFO1 and LFO2 - the Wavestation had two programming aces up its sleeve: vector synthesis and wave sequencing. The former, which was derived from Sequential's old Prophet VS synth (many of the Wavestation R&D team being former Sequential employees), allowed the four oscillators which constituted a Wavestation Patch to have their amplitude levels dynamically mixed, relative to one another, from either a programmable Mix envelope or the synth's front-panel Vector Position joystick.
Wave sequences were, quite simply, user-programmable sequences of the Wavestation's waves which could be assigned to its oscillators and either looped or else played as one-shot sequences while synced to an internal clock or externally-derived MIDI clock. For those musicians looking for something different to come from a synth, wave sequencing provided the real creative heart of the beast, allowing, as it did, a new sonic vocabulary to be created out of existing sounds.
Two years on from the Wavestation's Frankfurt Music Fair debut, there have been some significant additions to the synth's capabilities (turning it into the Wavestation EX), plus the introduction of a rack-mount version, the Wavestation A/D. The latter not only matches the features of the Wavestation EX, but also adds a feature not available on its keyboard counterpart, namely two rear-panel audio inputs (hence the A/D, for Analogue/Digital).
Since its arrival last Autumn, the A/D has consistently outsold its keyboard counterpart - which must say something about the desire of musicians to add modules to their setups, particularly as buying the A/D represents no significant saving in cost over the Wavestation EX.
My intention in this review is to look at the main areas of development on the Wavestation (EX and A/D) since I originally reviewed the synth (see MT, September '90). Therefore if you want background on the Wavestation and a fuller appraisal, I suggest you look back over that review.
In some ways the most significant addition to the original Wavestation is the addition of sampled instrumental sounds alongside the waveforms. Yes, Korg have added the acoustic and electric pianos, saxophones, flutes, slapped basses and drum and percussion sounds which people evidently want. Perhaps what it comes down to is that, if you're paying out a lot of money for an instrument - and the Wavestation isn't cheap - then you want as much scope from the sounds as you can get. Not that the extra sounds really substitute adequately in their scope for a full-blown sample-based synth.
The extra drum and percussion sounds are a welcome inclusion in particular, because the Wavestation excels at rhythmic patterns, courtesy of its wave sequences - as an early PCM card for the Wavestation, Drum & Percussion, very ably demonstrated. Indeed, many of the Wave Sequences in RAM3 show off the A/D's (and EX's) enhanced drum and percussion vocabulary. The inevitable grand piano puts in an appearance too, of course. It's much better than the piano which came on another of the early PCM cards; however, I wouldn't call it an elegant classical grand, it's got a more lively edge to it which makes it well suited to more contemporary contexts.
"The Korg Wavestation A/D is one of the most versatile, most powerful and most intriguing synths on the market at the moment."
Although the Wavestation may include more recognisable sounds now, once you get them into a wave sequence you can treat them as much more abstract material, thanks to the obscuring possibilities of sequence step crossfades.
The greater range of source sounds to choose from is reflected in the extra Bank (RAM3) of Performances, Patches and Wave Sequences, and extra Wave Sequence steps. And talking of steps, Korg have taken the unusual step on the A/D of leaving the RAM2 Wave Sequence Bank blank - the idea is to encourage you to get into creating your own Wave Sequences by giving you an otherwise unused area to play around in. Seems like a good move.
Eight digital effects have been added to the original set, bringing the Wavestation's total to 55. The new ones seem to have primarily been added because of the synth's individual outs, although the EX has the new effects too. These are Mod Pitch Shift-Delay (allowing the pitch of the audio inputs to be shifted), Stereo Comp-Lim/Gate (for smoothing out the level of the incoming signal, or in some cases adding more punch to it), Small Vocoders 1-4, Stereo Vocoder-Delay 1 and Stereo Vocoder-Delay 2. The Vocoders really open up a new sonic area on the Wavestation, but although they can be very effective on combinations of internal Wavestation sounds (using a rhythmic Wave Sequence to modulate a sustained pad sound, for example), the A/D's analogue inputs give it the edge over the EX - especially if want to get classic vocoded vocal sounds and so on. Vocoders work by superimposing the timbre of one signal (the modulator) onto that of another (the carrier); the Wavestation's vocoder effects draw on its FX busses (A-D) as modulators and carriers, giving you a great deal of flexibility in deciding what sound, or combination of sounds, you want to use for one or the other.
The audio inputs typify the "looking backward in order to go forward" philosophy underlying the Wavestation's design. Yes, the A/D has audio inputs "like the old synths used to". But all the developments which have taken place in digital synthesis and MIDI in the intervening years mean that new possibilities exist for the manipulation of audio data once it's in the Wavestation's digital domain.
The A/D's rear panel provides Input 1 and Input 2 jacks, together with level knobs and -40/-10/+4db gain switches for each jack, allowing the A/D to cope with a wide range of input signals. Incoming analogue signals are taken into the digital domain via 64 x oversampling ADCs. The Global page Analog Input Assign provides the parameters for initial control of the incoming audio signals. As well as being able to enable or disable the incoming signals globally, you can specify a MIDI channel, volume amount, filter cutoff point (12dB/octave low-pass filtering), Exciter amount and FX Buss routing for each of the two signals.
To pass the audio data directly to the Wavestation's effects, you enable one or more of the FX Busses A, B, C and D. In this way the Wavestation can be used purely as an effects processor for external sounds.
"The Wavestation's audio inputs typify the 'looking backward in order to go forward' philosophy underlying the Wavestation's design."
The MIDI Channel and Volume parameters between them allow independent automated mixing of the two input signals. When you edit the Volume amount (which controls the gain setting of the signal), MIDI controller #7 data is transmitted on the channel specified by the MIDI channel parameter; if you record this data into a MIDI sequencer and subsequently play it back to the Wavestation on the specified MIDI channel, it controls the Volume level remotely.
If you don't want the incoming signal(s) to be routed directly to the Wavestation's effects, you simply set all the FX Bus routings on the Analog Input Assign page to Off. As each signal can be routed independently, you could have one going straight to the effects while the other follows one (or perhaps both) of the two other possible routings. By assigning Wave 516 (Input 1) or Wave 517 (Input 2) to one of the four oscillators within a Patch, that oscillator will play whatever comes in on the relevant input, for as long as a note is being triggered via MIDI from your keyboard - in other words, the audio signal is gated by MIDI note ons and offs.
The other option is to select one of the two Waves as a step in a Wave Sequence. In this case the audio signal is only "let through" when its Wave's turn comes in the Wave Sequence - and then its appearance is governed by step duration and crossfade settings. In both cases (Wave and Wave Sequence) the input signals are passed through the Wavestation's synthesis parameters - although any relating to pitch are ignored - and on to the digital effects in the usual way.
If you want your incoming audio and your Wave or Wave Sequence to be synced together, the best way to achieve it is probably to sample the audio and then assign the sample to the relevant MIDI note - so you trigger the sample each time you trigger the Wave or Wave Sequence. The Wavestation is also able to sync its Wave Sequences to incoming MIDI clocks, so there are other possibilities there for anyone working in a sequencer-based way.
The Wavestation A/D is one of the most versatile, most powerful and most intriguing synths on the market at the moment. For the adventurous musician it offers unique creative possibilities, and, to my mind, any effort expended on getting to grips with it is sure to be amply rewarded in terms of sonic results. The A/D is, without reservation, an instrument well worth taking some of your time out to investigate.
Price Wavestation A/D, £1600; Wavestation EX, £1495; EXK-W expansion kit for the Wavestation, £400 including installation, latest software version and transport of instrument from local Korg dealer to Korg service dept. All prices include VAT.
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Review by Simon Trask
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