Audio Damage Tattoo - Manual (Page 23)

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Decay
The Decay knob controls how long it takes for the hi hat sound to fade out to silence. Turn the knob clockwise
to make the sound longer, anti-clockwise to make it shorter. As you would probably expect, the decay time of
the open hi hat voice is longer than that of the closed hi hat voice.
BPF Frequency and HPF Frequency
The hi hat voices employ a pair of filters to control their timbre. The hi hat sound is created by a complex tone
generator (modeled directly after circuits found in the TR-606) and a noise generator. The filters, one band-
pass filter and one high-pass filter, remove lower frequencies from this combined sound to create a thin,
metallic-sounding signal. The
BPF Freq and HPF Freq knobs control the operating frequencies of the two
filters. Use the BPF Freq knob to change the overall tone of the hi hat; use the HPF Freq knob to remove
lower frequencies making the sound brighter and thinner.
Noise Mix
The Noise Mix knob controls the relative loudness of the tone generator and noise generator in the hi hat
synthesizer. Turn the knob all the way to the left and you’ll hear just the tone generator, turn it all the way to
the right and you’ll hear just the noise generator. If the knob is at its center position the tone and noise
generators are mixed equally.
Cymbal
Synthesizing cymbal sounds is something of an uphill battle. Real cymbals produce extremely complex timbres
that vary dramatically depending on where you hit them, how hard you hit them, what you hit them with, etc.
Apparently displeased with their own efforts, Roland gave up trying to synthesize cymbals and used samples
in the TR-909, with debatable results. Strange as it may seem, we at Audio Damage are most fond of the
cymbal sound in the lowly Boss DR-110 drum machine, so it and the TR-808’s cymbal were the main
inspirations for Tattoo’s cymbal voice. True to the no-samples-allowed design philosophy, it synthesizes a wide
range of metallic timbres.
Tattoo’s cymbal has two sound-producing components: a set of oscillators that produce a dense, harmonically
rich tone, and a noise source. A controllable amount of white noise is added to create unpitched sound. Two
band-pass filters with different center frequencies produce two sound components from this signal. The lower
filter produces the bell-like “ding” sound component of the cymbal heard first when it is struck. The higher
filter produces the shimmering, high-frequency, sustaining portion of the cymbal sound.