How To Use Vocoder Microkorg

[Otilia Mojarro]

Get a decent dynamic mic like the suggested SM58 or one of the cheaper clones. If you are experiencing that your voice trancients dosnt "cut through" in the vocoder, you could also try a handheld condenser mic, though they are much more expensive.

Truth of the matter is that I have yet to hear a vocoder on a synth that cuts the mustard. There's just not enough presence and the consonants and sibilants do not cut through, leaving the end result sharp and a little muddy.

+1 on the SM-58. The condenser mic included is just to show you the vocoder is functional, and Korg doesn't want you to feel ripped off for buying a synth/vocoder and not getting a microphone. Just get a XRL to 1/4" cable and you should be set. If that fails, get a regular XRL to XRL cable and fed it into the microKOrg with a Whirlwind "Little Imp" (converter for high impedance XRL to line level 1/4") and that should be good.

What kind of voice stuff you gonna do thru the synth? Myself prefers the CAD24 for anything with cookie monster type voice. The AKG D880 or its version with switch for more normal voice. Somehow its treble voicing makes octave dropped voices not as good sounding imo. Shure SM58 is between those two for my occassional mic uses wise. I'd say put together a desired vocoder patch and take to store and try a few diff mics thru it and see which you like better.

If you decide you really want a condenser mic, might check crutchfield.com, yes is stereo store, But they at least used to carry a good condencer mic or two by technics for about $100. As part of accessorries for minidisc recorders etc.

Though inexpensive, was bout $58 when got mine, the Cad24 works better then lots of more expenisive ones I've tried. But does do demon voice narrations & cookie monster lyrics when I do voice things. So may not be appropriate for you. Lol.

A quick glance around the back reveals a 3.5mm headphone output, a pair of 3.5mm left/right line outputs, two sets of audio inputs, a trio of MIDI connectors (In, Out and Thru), a power switch and the connector for that justifiably hated external power supply! However, there are no sockets for pedals or footswitches.

The Micro's keyboard is a 37-key C-C type, incorporating velocity response, but lacking aftertouch sensitivity, and it's composed of mini-keys, which is a little strange to my way of thinking. Serious players will be dismayed by it, and yet it's not quite aimed at non-players either, as they would surely have been quite happy with even fewer notes?

I was concerned on first looking at the Microkorg that I was in for hard time programming the machine, given its relative paucity of controls (see the 'User Interface' box later on). To a great extent, I'm afraid my fears were realised. If you are heavily into sound programming, I'd strongly suggest you find a suitable computer editor, or get used to 'ship-in-a-bottle'-style twiddling. Also, thanks to the absence of any other form of screen, Korg have had to resort to cryptic LED messages to display some of the parameter values, and it will take time to become familiar with these.

At best, the Microkorg is four-voice polyphonic, and the voices are allocated depending on the voice assignment set for each of the two Timbres. If both Timbres are layered together in Poly mode, the synth will become two-note polyphonic. Mono mode is provided to emulate a true monophonic synth, whilst Unison mode layers all four Voices together with a variable degree of Unison Detune to create a richer, fatter sound.

Oscillator pitch is variable over a range of four octaves, with fine-tuning to one-cent steps. The range of effect of the bend lever from -12 to +12 semitones is adjustable, as is the vibrato depth imparted by the mod wheel. Portamento is available, and portamento time is adjustable, but unfortunately there is no option to specify a fixed portamento rate, making longer portamento times sluggish over short key spans, and rendering old Minimoog portamento lead sounds a tad difficult to emulate convincingly.

The 64 DWGS (Digital Waveform Generator System) waves hark back to the days of the DW8000. These waveforms are the result of additive harmonic synthesis, and usually sound glassy, hard-edged and 'digital'. They allow the creation of all kinds of metallic, bell and electric piano sounds which are normally outside the scope of a purely analogue synth.

Osc2 is an rather simpler affair, capable of generating only saw, square and triangle waveforms. Independent tuning is available to generate detuning or musical intervals in semitone steps. Once both oscillators reach the mixer they are joined by a noise generator, independent of Osc1. Finally, each of the three signals may be individually attenuated before passing to the filter.

The filter is again surprisingly advanced, with options for a full-blooded 24dB-per-octave low-pass filter, in addition to 12dB-per-octave low-, high- and band-pass variants. In addition to its basic cutoff and resonance controls, the filter has its own dedicated ADSR envelope generator and key-tracking, both with variable positive or negative depth controls, and it will happily go into self-oscillation when the resonance control is turned up sufficiently high. Both the filter and amp envelope generators are of the ADSR type, with the option to force the envelope to reset to zero amplitude each time a new note is played, or to pick up from the release level of the previously played note.

In the amplifier section, there's a simple level control to determine the overall patch level, although this acts as a balance between Timbre 1 and 2 when a layered patch is created. A pan pot determines left/right balance and variable key-tracking will increase or decrease volume level across the keyboard. The amp section also offers a useful distortion processor, a simple on/off control which relies on the levels set in the mixer to determine just how much distortion is applied.

The Microkorg's two LFOs are near-identical, with the exception that LFO2 offers an triangle wave rather than LFO1's sine wave, and also contains an unusual 'positive-only' square wave in place of LFO1's more usual positive/negative square wave. A positive-only wave can be useful, for example, where you might want a pitch warble to flip between the played pitch and a higher interval, whereas the more usual positive and negative wave would warble the pitch at above and below the played pitch. There's no positive-only equivalent for the sine or triangle wave, though, which could have been useful in simulating guitar vibrato. Key sync of the LFO is possible, as is tempo sync, so modulation can be synchronised to either the internal arpeggiator tempo, or an external MIDI Clock source at a variety of cycle values, from four beats per one cycle to one beat per two cycles.

As mentioned earlier, four so-called virtual patch routings are available, and it is here where much of the Microkorg's strength lies. Each Patch allows the selection of a modulation source and its application to a modulation destination, with a variable positive/negative intensity. Modulation sources include both LFOs, both envelope generators, velocity, keyboard tracking, and the mod and pitch wheels. Destinations include pitch, Osc2 tuning, noise level, filter cutoff, amplitude, pan and LFO2 frequency. As you might well imagine, this gives you scope for a whole world of modulatory mayhem, and some of the factory presets show what can be achieved with a little thought and application.

The Microkorg is supplied with its own mic for vocoding purposes, and although it's a little physically flimsy, it makes a fine job of it.Photo: Mark EwingThe cutoff points of the filters can be shifted up or down to raise or lower the overall frequency response of the vocoder effect (carefully set, this could allow you to simulate a male vocal from a female voice, or vice versa), and resonance may be added to colour the sound. The current vocoder frequency response can be 'frozen' at any time by pressing the Formant Hold button. For editing purposes, the filters are arranged as eight pairs, or 'channels' and, at the output of the carrier signal, each channel has an individual level and pan control. The Envelope follower sensitivity is adjustable, as are gate threshold and gate attack time. Controls are provided to determine how the modulator signal's high-frequency content will be treated, either passing through unhindered, or being heard only when a note is being keyed. The volume of the passed high frequencies can be altered for subtlety or overly sibilant effects, and experimenting with this can aid intelligibility if the modulator is a voice.

The vocoder modulation options are not as varied as they are for a synth patch, but this is to be expected. The carrier filters may be modulated by the amp envelope, either of the LFOs, velocity, keyboard tracking, the pitch-bend wheel, or mod wheel. The provision of individual volume and pan controls for each of the eight output channels is generous, and allows the creation of lush stereo spreads.

The supplied microphone slots into a socket on the rear of the case and has a flying lead that plugs into Audio In 1 via the 'condenser' mic mini-jack socket. A second 'dynamic' standard jack socket is also available to which line sources may also be connected, and there's a mic/line selector switch, which is a nice touch. Audio input 2, on the other hand, accepts line-level signals only. Both audio inputs have a small trim control knob by the socket (labelled 'Volume'!) in order to match as wide a range of sources as possible. Unfortunately, I found it all too easy to overload the inputs, yet keeping the level back didn't give me a hot enough signal into the vocoder. A compressor would help, but that's not really a sensible option if you're only using the supplied mic.

The Microkorg has are two onboard effects types: modulation and delay. Modulation effects are confined to three basic types: a flanger/chorus, ensemble effect and phaser, and the only controls provided are speed and depth. The Delay effects also come in three flavours: stereo delay, cross delay (where feedback is interchanged between left and right) and left/right delay (ie. stereo ping-pong). Despite their simplicity, the effects are of good quality. I particularly liked the phaser: it seemed capable of bringing out a certain 'graininess' in the synth's sound that reminded me of an old MXR stompbox.

c80f0f1006