How To
Program Synth Strings August 8,
2000 ~ Have you ever wanted to know how to make "String"
type sounds - also known as "Pads" - with your synthesizer?
Check out this "How To" article from AN1x User Phil - from
Australia no less! "You can
start with any Waveform, but a "Saw" is a good one to begin
with... Essentially a
Pad sound will have a slow attack and generally a longer
release, i.e., when you press down the key, the volume of
the note rises slowly and sustains until you release the
key, then the note slowly fades away. To get the
volume to act in this way, select the "VCA*" Knob Parameter
Group. *Note: "VCA"
stands for (V)oltage (C)ontrolled (A)mplifier. In the true
analogue world, a voltage is applied to the amplifier - as
the voltage is increased, this in turn raises the
amplification (or, Volume). To have the
volume rise slowly when you press the key, you'll need to
turn up the "Attack' (within the (A)mplifier (E)nvelope
(G)enerator). The "Decay" adjusts the time taken to come
back down to the volume set by the "Sustain". The "Sustain"
should be raised to the point that you wish the volume to
remain at whilst the key is still held down. Finally raise
the "Release" value to set the time taken for the sound to
fade away. There you
have it.... Instant Pad sound! To give the
sound a bit of character. That is, to have its tonal
characteristics change over the time the note sounds, you'll
need to have the filter 'move' with the sound. Select "VCF*"
Knob Parameter Group. *Note: "VCF"
stands for (V)oltage (C)ontrolled (F)ilter and works under
the same principal as the "VCA". With the
understanding of the Amp Envelope (ADSR), you can apply
changes that affect the filter in the same way. NOTE: When
making changes to the ADSR settings of the Filter Envelope,
you may need to adjust the 'depth' that the filter works to
by using the "FEG Depth" Knob, and
also the "VCF Cutoff" so that the changes are occurring
within an audible range. Add some "Resonance" and you're
sure to hear the results. Finally to
get some motion in the sound over time, you can modulate the
"VCF Cutoff" via an "LFO*". *Note: (L)ow
(F)requency (O)scillators don't make an audible sound.
Instead, the rising and falling voltage is applied to the
Filter to cause it to rise up and down at the same
rate. Press
"PEG/LFO" in the Knob Parameter Group, select an "LFO1 Wave"
type. Adjust it's speed (LFO1 Spd). Note: a low value = low
speed (Ideal for slow, evolving pad sounds). Finally go
back to the "MIX/VCF" Knob Parameter Group and adjust the
"FmodDepth". This knob determines what sort of range the
Filter will move through as the LFO cycles up and down. A
value of "0" equals no movement. By playing
with the "attack" of the AEG, you can move from a 'bowed'
sound to a 'plucked' sound. Also, if you have a low
'sustain' in the FEG, the lower the 'decay' of the FEG
(particularly with a bit of 'resonance' added) you can
create a more pronounced 'plucking' sound. You may have to
adjust the 'Cutoff' and 'FEG Depth' to hear the
modifications. For another
variation of the tone, why not use a "Pulse" wave and then
modulate it with an LFO. After selecting the "Wave" to
"Pulse" and adjust the tonal character using the "PW" to
adjust the width, apply some depth to the modulation using
the "PWM Depth" knob, and then use the "PWM Src" knob to
select one of the two LFO's. Adjust the speed of the
corresponding LFO and you're in business! The are
literally an infinite amount of variations and
configurations possible. Have
Fun!" Phil Booth
<accession@optusnet.com.au>
By Phil Booth from JDLX-Musique.com
Originally posted Summer 2000.