Waldorf Edition - Manual (Page 27)

Waldorf Edition
User Manual 27 Waldorf
Programming Drum Sounds
To understand how to create drum sounds, you should know a little about how the
classic drum machines worked. The following sections give some insights how parti-
cular sounds were built and information how to achieve similar results on the Wal-
dorf Attack.
Roland TR-808 Bass Drum
On the Roland TR-808, this sound was made by one filter with a high resonance set-
ting,
triggered by a short impulse. Two controls were provided to adjust the bass drum:
"Tone" was used to set the pitch by changing the filter's cutoff frequency, and "De-
cay" was used to set its resonance, which in turn controlled the decay rate.
On the Attack, you could use the filter´s self-oscillation by triggering it with a short
noise impulse made by the second oscillator, whose volume you can control by an
envelope.
But a better way is to use Oscillator 1 playing a sine wave, and by changing the
initial click impulse by means of the filter.
Roland TR-909 Bass Drum
The Roland TR-909 used an oscillator and a noisy click, controlled by three envelo-
pes, to create a bass drum sound. The oscillator played a sine wave whose pitch
was controlled by an envelope and the "Tune" control. The rate of the envelope’s
decay was not adjustable.
This oscillator signal was routed to an amplifier with an envelope whose "Decay" pa-
rameter adjusted the decay rate of the envelope. The second part of the bass drum
sound was made with a short impulse and a low pass filtered noise generator, both
summed and routed into another envelope that controlled their output volume. The
"Attack" parameter controlled the overall pulse/noise level, and the decay rate of the
envelope was not adjustable.
On the Attack, you can make this sound as follows: Oscillator 1 plays a sine wave,
and Envelope 2 is used to modulate its pitch. This means that the pitch of the oscilla-
tor becomes higher or lower depending on the setting of the Decay parameter of En-
velope 2, but this slight variation doesn't affect the drum sound once it has been set
up.
The noise of the impulse can be ignored, because it is low pass filtered anyway. But
how do we create an impulse with the Attack? The answer is simply to use a square
wave with a very low pitch setting for Oscillator 2, and to control its level with a
very short envelope. Now we have an impulse. This impulse is low pass filtered af-
terwards with a slightly resonating filter, preferrably set to around 5000Hz with a re-
sonance of around 18%.
With the Oscillator 1 Pitch and Pitch Env controls you can adjust the sound of the
bass drum, while Envelope 2 Decay controls its length.