Roland MC-909 - Manual (Page 54)

54
Patch Edit
How a Patch Is Organized
The type of sound most commonly played on the MC-909 is called a
Patch. Each Patch can contain up to four Tones.
fig.2-01.e
You can turn the Tones in a Patch on or off. Only Tones that are
turned on are heard when you play the Patch. (p. 56)
You can also set the structure of a Patch to specify how Tones 1 and 2
and Tones 3 and 4 are combined. (p. 66)
How a Tone Is Organized
Tones are the smallest programmable unit of sound on the MC-909,
and are the basic building blocks that make up a Patch. You can’t
play a Tone by itself-it can only be played as part of a Patch or
Rhythm Set. A Tone consists of the following five components.
fig.2-02.e
WG (Wave Generator)
This selects the PCM waveform material that provides the basis of
the Tone. Two waveforms can be assigned to each Tone.
The MC-909 has 693 different waveforms. (See Waveform List p.
150.)
All Patches built into the MC-909 consist of combinations of Tones
based on these waveforms.
TVF (Time Variant Filter)
This specifies how the frequency components of the Tone change.
TVA (Time Variant Amplifier)
This determines how the volume and panning of the Tone change.
Envelope
An envelope applies changes to the Tone over time. There are
separate envelopes for pitch, TVF (filter) and TVA (volume). For
example, you would use the TVA Envelope to modify the way in
which the Tone attacks and decays.
LFO (Low Frequency Oscillator)
Use the LFO to create cyclical changes-or cyclical “modulation”-in a
Tone. Each Tone has two LFOs. An LFO can be applied to the Tone’s
pitch settings, TVF (filter), and TVA (volume). When an LFO is
applied to pitch, a vibrato effect is produced. When an LFO is
applied to the TVF cutoff frequency, a wah-wah effect is produced.
When an LFO is applied to the TVA volume, a tremolo effect is
produced.
Tips for Creating a Patch
• Choose a Patch that’s similar to the sound you wish to create.
When you want to create a new sound, it’s a good idea to begin
with a Patch that’s close to the sound that you have in mind.
Starting with a Patch that bears no resemblance to the one you
want to create is likely to result in much more programming
work for you.
• Decide which Tones will sound
When creating a Patch, it’s important to decide which Tones
you want to use. It’s also important to turn off unused Tones to
avoid wasting voices, unnecessarily reducing the number of
simultaneous notes you can play.
• Check the way in which the Tones are combined
Structure Type 1&2 and 3&4 are important parameters that
determine how the four Tones are combined. Before you select
new Tones, make sure you understand how the currently
selected Tones are affecting each other.
Example 1:A Patch consisting of only one Tone
(Tones 2—4 are turned off).
Example 2: A Patch consisting of four Tones.
Tone
1
Tone
2
Tone
1
Tone
4
Tone
3
Tone
4
Tone
2
Tone
3
WG
Pitch
Envelope
TVF
TVF
Envelope
TVA
Envelope
TVA
LFO 1 LFO 2
Tone
audio signal control signal
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