Файл: Clavia nord lead 2 v1.0 (eng manual).pdf

After the envelope has reached full level, it starts to fall back again. How long this should take, is set with the Decay parameter.

Level

Time

Attack Decay (time) (time)

Key Down

The level of the envelope does not necessarily have to fall all the way back to zero level at the end of the Decay. Instead, the ADSR-envelope has a Sustain setting used to determine the level the envelope should rest at, after the Decay. If you for example want to create a flute sound, you would have a fairly high Sustain setting on your Volume envelope, since a flute tone basically stays at a steady level for as long as you play it. On the other hand, for a piano sound, you would want a Sustain level of “0”, since a piano sound decays to silence if you hold the key long enough.

Level

Sustain (level)

Time

Attack Decay (time) (time)

Key Down

Please note that the Sustain parameter represents a level, but all other envelope parameters represent times.

As described above, the envelope stays at the Sustain level until the key is released. It then falls back to zero level. The time it should take for this to happen is set with the Release parameter, which works just as the Decay, only it is not applied until you lift your finger off the keys.

Level

▼If you set Sustain to full level, the Decay setting is of no importance since the volume of the sound is never lowered.

Level

Time

▼If you set Sustain to 0, the sound will become silent after the Decay phase is finished. With short Attacks moderate Decay times, this can be used to simulate the behaviour of a plucked string instrument (guitar, piano etc) where the sound always decays to silence after a while.

Level

Time

▼If you release a key before the envelope has reach its sustain, it will immediately “jump” to the Release. The effect of this can be studied in the illustration below.

Level

Time

▼Often envelope levels can be made to vary with how hard you play the keys. This is used to make a sound vary with your playing style, for example to make the sound brighter (filter envelope) or louder (amplifier envelope).

AD-Envelope

A simpler form of envelope has Attack and Decay parameters only, and is therefore called an AD-enve- lope. In effect, the AD-envelope behaves like an ADSR-envelope with Sustain set to 0 (see the picture at the top of this page??). This type of envelope, often with amount and inversion controls, is suitable when you want to affect the start of the sound only.

On the Nord Lead 2, the Modulation Envelope is of AD-type. Typically, it can be made to modulate the FM amplitude or the pitch of Oscillator 2, to create a different timbre during the attack part of the sounds.

LFOs

An LFO is an oscillator, just like the ones that produce the sound in a synthesizer, but with two main differences:

▼The LFO produces very low frequencies, most often below the hearing range (up to 20Hz).

▼The LFO is not used to produce sound, instead it is connected to other modules to provide modulation of parameters.

If you for example route an LFO to pitch, you get a vibrato. If you route it to the filter’s cutoff frequency you get a wah-wah type of effect. And if you route it to the amplifier of an instrument you get a tremolo.

The three basic parameters for an LFO are Waveform, Rate (frequency) and Amount:

▼The waveform determines the type of vibrato, for example “regular” (triangle or sine), ramp (sawtooth) or random.

▼The Rate determines the speed of the vibrato.

▼The Amount controls to what degree the LFO affects its destination.

12. MIDI Implementation

Controller Number List

The following is a list of the MIDI Controller numbers used for all knobs and buttons on the front panel. See page 72.

▼The reception and transmission of Controllers can be turned on/off. See page 61.

▼Buttons that control “on/off” functions have a Controller value of “0” corresponding to the “off” position and a value of “on” corresponding to the “on” position.

▼Buttons that step through various possibilities start with a Controller value of “0” for the “lowest” setting and then increment with a value of 1 for each step upwards.

If you want to send Controllers to Percussion Kits, proceed with caution! The Controller message you send will affect the percussion sound that was last selected for editing, by pressing a black key on the keyboard (see page 30).

In addition to the above, following controllers are used:

▼The Modulation wheel transmits and receives Controller 1.

▼If the Pedal input is used with an expression pedal, this is transmitted and received as Controller 11.

▼If the Pedal input is used for sustain, this is transmitted as Controller 64 (Damper Pedal)

▼Bank Select messages (Controller 0 and 32) are received.