Synthesizer & Vocoder
Reviews : Keyboard
The Radias is described by Korg as a synth
and vocoder, but that's somewhat modest — it manages to cram analogue
modelling, S&S, FM and formant synthesis into its stylish frame,
plus a host of sound-shaping and triggering facilities. Plus that vocoder...
Photos: Mark Ewing
The Radias module sitting centred in its optional
RD-KB keyboard frame. If you wish, you can slide the Radias around from
left to right to your taste, and if you situate it at either the left or
right extremes of the keyboard frame, a blanking panel is supplied to
fill the gap at the opposite side of the frame, as you can see from the
picture overleaf.
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One of the most talked-about debuts at NAMM 2006 was
the Radias from Korg. Oddly named and visually striking, the Radias is
powered by 'Multi Modelling Technology' — a mixture of analogue
modelling, PCM waveforms, a simplified FM implementation and formant
(vocal-type) waves. We first saw MMT on the EMX1 Electribe, but Korg
have taken things further for the Radias, plundering the mighty OASYS
workstation to ensure the modelled analogue oscillators are low on
aliasing, high in fat. Throw in a versatile filter section, a vocoder,
powerful distortion and waveshaping, plus a virtual patch system and
decent effects, and you have a stonking sound engine. If it's rhythmic
fun and interaction you seek, there are drum kits, an arpeggiator and
dual step sequencers. All this is housed in a body that bears a passing
resemblence to the MS2000R synth — although in a splendid silver finish.
The Radias is available in two forms: as a
stand-alone rack unit (the Radias R) or accompanied by a dedicated
keyboard and rack frame, the RD-KB (shown connected to the Radias in the
picture above). When racked, it occupies 4U of space, but as its
connectors are not recessed, you need to allow at least another rack
space above it for cable connections, which is a bit of a waste. This is
made more irritating because the Radias has a lovely slimline design,
perfect for slipping into a small mixer flightcase.
The front panel is initially bewildering and you'd
be forgiven for thinking 'Electribe' or 'Groovebox' as you gaze at pink
lights, and knobs backlit with an orange glow. I personally found the
knobs on the small side and packed rather too closely together for my
fingers, which was a shame. Generally, though, once you get used to it,
the user interface isn't too bad, and various shortcuts are employed
that you soon come to appreciate. For example, the 16 trigger buttons
along the bottom edge of the module serve multiple purposes, switching
on trigger steps in the arpeggiator or sequencer, selecting pages in the
menu system, or playing notes if the keyboard is not present.
The 128 x 64 LCD is reasonably informative and
navigation is logical, although some aspects could still be improved.
For example, a small LED flashes when you turn a knob through its
current stored value. This is fine for a simple piece of gear like an
Electribe, but feels much too basic for a high-end instrument with a
decent display. Why not show the old and new values on screen, as Access
or Novation do? In fact, you don't even see the values on-screen at all
unless you specifically go into Edit mode. This can be confusing —
especially if you have configured the knobs to 'Catch' mode (to avoid
any audible parameter leaps when tweaking a patch), because you are
given no visual clue whether to turn the knob to the left or right in
order to pass through the patch's stored value. When in Edit mode,
turning a physical control takes you straight to the relevant Edit menu.
Dedicated buttons are available to switch between
Program or Drum Mode, or activate the vocoder. Despite the Radias's
abundant multi-functionality, it only took me a few days before I was
flying around confidently. I have to say my early progress was hampered,
rather than helped, by the manual, which has no index and is strewn
with frequent cross-references to other pages, making it a drag to read
through.
Other than its lack of recessed sockets, the rear
panel contains the expected stuff. So, alongside the three MIDI ports is
a USB connector that acts as a MIDI interface for your PC or Mac. The
special connector for use with the optional RD-KB is here too, as is the
on/off switch and connector for the external power adaptor. This
adaptor, incidentally, is one of those with its own on/off switch,
perfectly positioned to be caught by accident and cause all kinds of
confusion in a live situation. It gets the thumbs down from me.
Audio connectivity is courtesy of a master stereo
pair plus two individual outputs — there's no digital I/O at all.
External processing is one of the Radias's strong points, so two audio
inputs are provided, plus a condenser mic input and a switch to select
between condenser, line and dynamic mic types. As the optional keyboard
has no controls of its own, there are two assignable pedal inputs on the
module.
The Radias offers up to 24-note polyphony, which is
acceptable but, these days, not over-generous. Various factors such as
the oscillator waveform, unison, drive and the vocoder eat further into
this allocation, although Korg are vague on the exact costs of each.
There are 256 Programs in total, each consisting of up to four
'timbres'. And as there is no Multi or Combi mode, each of these timbres
is what we'd typically call a Program or Patch. A timbre can be given
its own key (but not velocity) range and MIDI channel and can be
triggered by the arpeggiator or sequencer before being sent on its way
via a two-channel EQ and two dedicated effects. Each timbre is finally
directed to the main stereo outputs through the master effects
processor. Interestingly, a timbre can be positioned anywhere between
the main output and the individual outputs — that is, instead of
assigning it wholesale to individual outputs, you can assign in
proportions, so that, say, 70 percent of a signal passes through the
main outputs, and the other 30 percent passes through the individual
outs, all without altering the left-right panning position (which can
still be set separately). Seen previously on synths like Access's Virus,
this can be used for quadraphonic panning and would be of great value
in a surround system. It's just a shame that you can't modulate the
position between the outputs with a mod sequencer or the virtual patch
system.
Programs are organised into 16 banks of 16 (A to P),
selectable either via the buttons, data-entry knob or by category (with
16 to choose from). A quick play through the factory sounds may make
you feel you're a terrible programmer (it did me); I was especially
impressed with the anthemic trance creations that you can easily imagine
doing the business at parties or festivals.
Here the Radias has been slid to the left end of
the frame, and the blanking panel placed on the right so that a laptop
can be used alongside the module.
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Although there are some classy factory sounds, Korg
clearly intend you to program your own as quickly and intuitively as
possible. To this end, 128 templates are supplied with names such as
'Sub Bass', 'Trance Pad' and 'Windstorm' to point the way. As you gain
expertise, you can replace these templates with your own — a neat idea
that genuinely speeds up patch creation.
Some aspects of the OS do slow you down slightly.
For example, you can't set MIDI channels, outputs, key-ranges and other
timbre parameters unless they are currently active. Worse, I
occasionally misread the mode I was in (the Edit button is just one
glowing pink button amongst many) and tried to hit a button to access a
menu page, only to change patches instead and lose work in progress. So
it might be nice if the Radias had an edit buffer to prevent this kind
of accident, especially in a live context. Whilst I'm asking for things,
it occurred to me how much nicer it would be if, when storing a patch, I
could see the name of the patch in the destination slot rather than
merely its number.
If you begin your programming adventure with a
single timbre, you soon discover a highly sophisticated synth engine
beneath the flashing, occasionally dazzling facade. Although the Radias
conforms to the standard oscillator/filter/amplifier model, each of
these stages boasts some very sophisticated enhancements. Let's take a
quick tour starting with Oscillator 1 — the more complex of the two
present. Its panel features two Osc Mod controls that perform different
duties according to the waveform selected. Above these are wave selector
buttons offering the modelled 'traditional' waveform types (saw,
square, triangle and sine). But there's also the Formant wave, which
mimics tones created by a human mouth. Choose this waveform and the
first Osc Mod control sets mouth shape (and hence the vowel sound
produced) whilst the second sets mouth size. The remaining choices are
noise, synth or drum PCM waveforms, or the audio input.
Inclusion of sampled waveforms is a real bonus,
previously seen in such synths as the Novation KS series. The Radias has
64 of these samples, including electric pianos, organs, strings,
choirs, guitars and some very useable electric and acoustic basses. If
you get the chance, check out Radias programs G12: 'A.Guitar', H08:
'Organ Bass', J13: 'Big Bee' (cool organ and drum accompaniment) and
L03: 'Acid Jazz' (featuring impressive acoustic bass and electric piano)
to see how useful they can be.
As well as the Synth PCM section, there are 128 drum
samples onboard. The emphasis is on kicks and snares, but you'll also
find a tabla, djembe, and various Wavestation-like voice segments. You
can use these sounds in your patch creation but the Radias also provides
a separate Drum mode for building complete kits, which we'll come to
later. For now I'd like to consider some of the remaining Osc Mod
options. Waveform modulation is fairly straightforward and accounts for
warping and pulse-width modulation of the analogue waves. Cross
modulation is ideal for harsher, often atonal stuff, whereas Unison
simulates the rich, detuned sound of five oscillators but without
affecting polyphony (unlike the dedicated Unison button, which stacks
Radias voices). Finally, VPM is Korg's version of FM synthesis, and
recalls the sounds of Yamaha's 1980s DX synths.
Already you can see there's tremendous scope for
tonal variety — and that's just from Oscillator 1! It's forgivable that
the second oscillator is simpler — it offers just modelled analogue
waveforms, plus tuning controls (which, incidentally, Oscillator 1
lacks) and a trimmed-down modulation section. However, even here useful
tools are found, in the form of ring modulation and oscillator sync.
These can be combined to form 'RingSync', which is biting and slightly
nasty!
The twin-filter arrangement is very versatile, not
least because Filter 1 offers a continuously variable multi mode capable
of sweeping through 24dB-per-octave low-pass and 12dB-per-octave
low-pass, high-pass, and band-pass types (or Thru mode, which is
equivalent to turning the filter off). Filter routing may be configured
as Single (ie. only Filter 1 is active), Serial (the output of Filter 1
passes into Filter 2), Parallel (both filters process both oscillators)
and Individual (Oscillator 1 is routed to Filter 1, Oscillator 2 to
Filter 2). It doesn't quite match the flexibility of, say, the Alesis
Ion (and there's no balance control between filters, as on Access's
Virus) but it's as versatile as you'll need for most applications.
Filter 2 lacks the smooth fade between filter types, and offers just
12dB-per-octave low-, high- and band-pass filters, but adds a comb
filter. This is rather nifty and responsible for all manner of metallic
chorus or rich flanging effects (check out patch F10: 'CombZilla' if you
can).
The Radias module detached from its optional keyboard.
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Having concentrated on the oscillators and filters,
I'll quickly note that there are two LFOs and three envelopes. The first
two envelopes have dedicated knobs for control of filter and amplifier,
whilst Envelope 3's role is freely assignable. I must draw your
attention to the configurable decay/release curve of the envelopes.
Decay is one of the most significant components of a bass line or a fast
sequence and a synthesizer with only a linear decay will never
reproduce those satisfying blips that many of us crave. With five
separate curves available, this will never be an issue with the Radias.
Staying on the subject of bass for a moment, check out the patches N07:
'Tek Seq Bass' and D08: 'Pulse Bass' if you don't believe a modelled
analogue can hold its own in the lower regions!
The end of the synthesis chain is the amplifier
section and this one is a little different, courtesy of the Drive/Waveshaper selector. Choosing the first of these overdrives the
output in a way that sounds refreshingly warm and natural, while various
options lurk in the Waveshaper, including a decimator (lo-fi mayhem!),
electric pickup simulator, various sub-oscillators, and more.
Waveshaping gives you lots of variations on waveform distortion — many
of which you might actually use. Signals can be passed through the Drive
or Waveshaper either before or after they pass through Filter 1; if you
choose 'before', you can then tame some of the harsher distortion with a
low-pass filter.
As well as the aforementioned option to split the
output of a sound proportionally between the two pairs of outputs, you
also have the option to send the output of the timbre to an internal
buss. This can then become either a carrier or modulator in the vocoder,
or be used to drive the envelope follower. This envelope follower is
'common' amongst all the timbres, so it can be employed for various
triggering and modulation duties. Interestingly, it can also trigger
notes or chords of up to eight notes from a variety of input sources.
You could use it to trigger a Radias kick from an external audio source,
to take just one example.
The remainder of the synth engine isn't without its
charms, either. There are five different portamento curves, giving ample
variation in response and playability. And if you wish to depart from
well-tempered scales, there are 10 alternatives available, including a
user scale. Naturally, the Radias may be played polyphonically or
monophonically, with the usual mono options of low-, high- and last-note
priority as well as single (legato) or multi triggering. The 'virtual
patching' system seen on the MS2000 is present too: up to six separate
modulation sources can be assigned to various destinations. And if
Korg's implementation of this may seem simplistic when compared to that
of Alesis, Access or Waldorf, at least it is quick and easy to use. It
has just 15 possible sources (five of which are incoming MIDI CCs) and a
mere 15 destinations. I'd have hoped that all the front-panel knobs
could be modulated, but this is not so. You can't modulate the effects
parameters, for example, but you can modulate parameters such as Filter 1
type and Oscillator 1's first control knob, although not the second.
Vocoder & Drums
Korg products have often incorporated vocoders
innovatively, and the Radias is no exception. This vocoder has 16 bands,
each with individual Level and Pan controls. A button selects whether
the Radias's row of 16 knobs will adjust the individual vocoder band
levels or their panning. But the best part is the Formant Motion
function. This is a means of recording phrases, or any chunk of incoming
formant information, and storing it for mic-free use later. Unlike
samples, formant motions always play back at the same pitch/tempo they
were recorded. Some of the factory sounds are used to cheesily extol the
power of the Radias and will be amongst the first to be replaced when
you get it home! Korg suggest ideal formant sources might include the
spoken word or jazzy scat singing, but I got equally dramatic results
from explosions, drum loops and short-wave radio noises. You can store
16 separate formant recordings (automatically named 'Motion01' to
'Motion16'), each of up to 7.5 seconds.
Having made the vocoder active, many of its
functions can be operated by the panel knobs, denoted by the
black-framed panel labels. Or you can navigate via the usual menu system
that will take you through the Modulator, Filter and Carrier pages. In
these pages, you select one or two (merged) Carrier inputs from any
timbre, External Input 1 or the internal buss. The Modulator takes its
input from either External Input 2 or, again, the internal buss. If you
require traditional vocoder effects, you connect a microphone to
External Input 2, specify the Carrier as an existing timbre and speak,
sing, gargle or grunt to your heart's content. There are some nice
Kraftwerky sounds already on board and, apparently, a headset microphone
is planned for inclusion with the Radias, although it wasn't supplied
in time for this review.
There are 32 drum kits on board, each consisting of
16 PCM samples assigned to a different note on the keyboard (or the 16
step buttons if you're working with the module alone). Typically you'd
source each drum from the 128 drum PCM waves of Oscillator 1, but the
Radias doesn't force you to do this. Drum voices can be made using any
part of the synthesis engine — and therefore you can concoct some
radical electronic kits, as previously heard on the marvellous ER1
Electribe. However, the Radias does it better — as hinted at in the
excellent selection of factory kits. The only niggle is that for some
reason, you can specify only a single timbre to hold a drum kit.
The Radias features two step sequencers, each up to
32 steps in length (they can also be combined to form a single 64-step
sequence). Unlike their CV/Gate ancestors, these sequencers are up to
eight-note polyphonic and are recorded in step time from MIDI input. A
button is provided for rests or ties, but otherwise you just bang in the
notes and let the Radias worry about their timing. During playback you
can change whether individual steps of the sequence are active or not
with the 16 front-panel buttons.
Each sequence has its own length, direction and time
base, so even with just two of them you can produce some
complex-sounding patterns. Unusually, you can clock the sequence using
incoming notes by setting the Runmode parameter to 'step' — one offshoot
of this might be to use the envelope follower and the internal buss
system to step through your pattern using audio triggers generated by
another timbre.
In addition to the two note sequencers, each timbre
features three modulation sequencers. In brief, a modulation sequencer
can control most of the continuously variable Radias parameters,
although not all. Mod sequences share a common length, direction and
resolution, a fact that reduces their appeal slightly. Each can output
smooth or stepped controller curves and offers an easy way to introduce
evolving changes to a plain note sequence, for example. Modulation
sequences can be recorded in real time, simply by selecting the sequence
to use, holding the Rec button and turning a knob, or you can set the
values with the 16 knobs directly. Taken as a package, the Radias
sequencers are fun and mildly diverting, although they lack the kind of
interactivity and addictive complexity found on synths such as Dave
Smith's Evolver, or stand-alone hardware step sequencers.
The arpeggiator contains many typical features
including five selectable directions, range, clock resolution and swing,
and it can be confined to specific regions of the keyboard. Combine it
with a couple of note sequences with sync'ed delay effects on each
timbre and you can happily noodle away for hours. A dedicated Latch
button ensures the noodling can continue even when you need to go and
get a beer, or something to eat, or attend a few classes. In common with
the step sequencer, you can set the active steps, overall pattern
length and the duration and velocity of individual steps in real time,
for even greater performance gratification. Annoyingly, though, when you
stop the arpeggiator it also stops any step sequencers that may be
active in other timbres.
The Radias has a fairly conventional back panel,
with the usual MIDI trio, USB connector, and quartet of outputs, plus a
stereo input pair with one switchable input level — but there are one or
two oddities. Firstly, there's that non-standard power supply socket on
the left, then there's the 'To Kybd' connector in the centre, which, as
the cryptic abbreviation suggests, is where the multi-pin cable goes
which connects the module to the optional keyboard. Finally, there's a
dedicated capacitor mic input.
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Each timbre has a two-channel EQ plus two insert
effects. Here Korg have really excelled, with 30 different types
available. Many of the effects parameters can be assigned for panel
control, with two knobs (per insert effect) for those you deem most
important. A button toggles which of the effects is currently tweakable.
Finally, there is a master effects section, also with an assignable
control knob.
The effects encompass a wide and varied range,
including a compressor, stereo filter, distortion, tube simulations,
reverbs and various delays (including tape echo). The list continues
with a flanger, chorus, phaser, pitch-shifter, ring mod, tremolo,
vibrato, rotary speaker, and odder types such as 'talking mod' and
'grain shifter'. The latter is a particular favourite of mine from the
ESX1 Electribe (although it sounds cleaner here); I often use it to warp
sounds so they resemble the artifacts of low-quality time-stretching.
The overall quality of the effects is well up to
scratch — the reverb easily trounces the metallic squawk of my
Electribe, for example. As with other areas of the Radias, effects
templates are available to speed up programming or to simply allow you
to save your favourite settings for quick retrieval in any patch. There
are some restrictions on usage, though, based on the DSP required for
specific effects. So 'Rotary Speaker', for example, is a 'double-sized'
effect, and if it's used as Insert Effect 1, no effect can be used as Effect 2. Similarly, some parameters are available when the effect is
used as an insert, but are unavailable when it's used as a master
effect. And if you use two insert effects that incorporate a delay time
parameter, the maximum overall delay time is reduced to one second.
Perhaps the biggest single drawback is that the master effect is global —
there are no individual send levels for each timbre.
The Radias is supplied with Mac/PC editing software,
plus a USB driver for connection to a computer if you don't have a MIDI
interface. Actually, I couldn't get the USB driver supplied with the
review Radias to work on my PC, but I did connect via the five-pin MIDI
sockets without any problems.
The software renders some tasks much, much easier
than on the synth itself. For example, you can remap every knob to the
MIDI continuous controller number of your choice — a superb feature that
all synths should have in my opinion — and the ability to view and edit
all assignments on a single screen is nothing short of brilliant. All
the edit screens are clear and straightforward, and perhaps the
strongest point of the software is that you can grasp the true depth of
the Radias clearly, without excessive flashiness. The visual effect of
the formant waves is both cool and informative, and you can even perform
some basic editing of these, such as normalising and trimming. You can
also compile your own library of formant motion recordings on disk to
import whenever you like. I'd have loved to see a means of importing
samples and converting them to formant motion directly, but perhaps I'm
just being greedy...
The Radias is a jack of all trades and can be
treated equally as a souped-up Electribe or a well-specified modelling
synth. Either way, it sounds fantastic, cramming in a whole host of
interactive and innovative features, with only the occasional
over-simplification. The filters are superb, and being able to
continuously sweep between different filter types is a creative yet
uncomplicated way to generate new sounds and textures. The modelled
analogue oscillators are awesome, and the inclusion of other oscillator
types, samples and drum kits opens up a vast number of options from
remarkably few panel controls. For live performance, the included step
sequencers, mod sequencers and arpeggiator are also handy.
The good stuff keeps coming. For example, the
vocoder is a class act. I've heard others with more features, more
bands, and more bells and whistles that still don't sound half as
musical as this one. And you might initially write off the storing of
user formant data as a gimmick, but it most definitely isn't — not only
can you use 16 of your own phrases to drive the vocoder, but there's no
reason to restrict yourself to vocal recordings at all. I wonder if,
perhaps, Korg are already at work on a bigger Radias (codenamed
'Diamater', 'Circumferance' or some other warped spelling, perhaps) with
fully-fledged sampling? This seems like the logical next step to me.
Whether many will feel the keyboard adds anything
worthwhile to the system, I don't know. But at least it's relatively
affordable and its unusual connectivity leaves the MIDI input free to
accept external MIDI clock signals. So often with modules, you need a
MIDI merge to combine clock and keyboard; Korg at least avoid this
pitfall.
To round things up, I was most impressed with the
Radias's synthesis, drums, effects and vocoder. I'm still not too sure
whether it is intended to compete with a fully-fledged modelling
synthesizer such as the Access Virus TI, but sonically it competes
pretty well. Ultimately, how a synth is categorised matters less than
what it can do for you. I think if the Radias's price tag were
just a little lower, it would make an even more tempting addition to any
system: it has ways to slot into almost any niche. This versatility
could see it make a lot of friends — as it has with me!
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