Operation Manual

2.2 Tutorial 2 Playing a Synth with a Keyboard 32
Playing
The ADSR can shape the amplitude in many different ways. This is one of the most important
components in the characterization of a sound. For example, a piano sound has a completely
different envelope than does a violin or a trumpet. They are, of course, very different in timbre too,
but for now let’s concentrate on the envelope. A piano has a very sharp attack, a long decay, no
sustain and no release. Try to set the ADSR to those settings. Because there is no sustain in this
example, the sound starts to decay shortly after you press keys.
Now let’s try to produce a violin-like envelope. This envelope is very different from that of the
preceding example, since on a string instrument a note is held as long as the string is bowed. Since
a violin’s sound doesn’t appear immediately, select a long Attack. Now choose a short Decay, a
high Sustain level (since the note is held as long as the bow plays the string), and a Release that is
not too long. Now the note will play until you release the key.
Step 4: Filter Modulation
Description
There are no new modules in this step, but we’ll explore other possibilities of modulation with
the modules we already have. First, we’ll have the Keyboard modulating the Vlowpass2, which
will cause the Vlowpass2 to change the cut-off frequency according to the notes played on the
Keyboard. This enables one to change the harmonic content of a sound with the pitch of the note
played, which is a behavior found in many acoustic instruments (piano for example). Second, the
ADSR will also modulate the Vlowpass2 so that the cut-off will move according to the envelope.
Again, this is a very natural acoustic and musical phenomenon.
Construction
• First select and delete the wire linking the LFO and the Vlowpass2 modules.
• Pull a wire between output 1 of the LFO and input 2 of the VCO module.
• Pull a wire from output 2 (pitch signal) of the Keyboard and connect it to input 3 of the
Vlowpass2 filter. Note that you can pull as many wires as you want out of an output, but you
can only connect one wire to an input.
• Pull a wire from output 1 of the ADSR and connect it to input 2 of the Vlowpass2.
• Save this instrument so that we can use it in Tutorial 3.
Playing
Try changing the parameters of the ADSR and hear the changes in the filter response. You can
control the amount of modulation of both the ADSR and the Keyboard with the two knobs, mod1