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Operating Instructions
The following will be a description of the pots and switches in the 3031. Refer to the diagram
at the end of this document for a drawing of the front panel.
Reading the front panel for the 3031 from left to right:
TUNE: Alters the frequency of the VCO and thus tunes the whole instrument.
SLIDE: Controls the amount of portamento on the pitch when the note changes and slide is
enabled. The little red LED will light if the slide is active.
VCO WAVE: The VCO produces two basic output waveforms. The square wave, a hollow
sound; and a sawtooth wave, a more brassy sound. The WAVE switch actually controls two
things. When SAW is selected, the sawtooth output of the VCO goes into the audio input of
the filter. However, it also routes the square wave to the filter modulation pot. When SQR is
selected, the square wave is sent into the filter’s audio input, and the sawtooth goes to the
modulation pot.
SUB OSC: Adjusts the volume of the discrete sub-octave generator. This will add a triangle
or a sawtooth wave output one octave below the VCO’s pitch to the filter input, for really
deep bass.
SUB OSC WAVE: Selects whether the triangle or the sawtooth output of the sub oscillator
is sent to the filter’s audio input. The triangle will give you deep bass without the harshness
associated with normal square wave waveforms. The sawtooth is far more bolder and
harmonically rich, but I think it still sounds better than the TB3030’s square wave.
FREQUENCY: Alters the voltage controlled filter’s cut-off frequency. The more clockwise
the pot the brighter the sound.
RESONANCE: This alters the amount of feedback applied to the filter. What this does is to
create a peak in the filter’s response. Thus certain frequencies are heavily emphasised. It also
controls the amount that the accent signal modulates the filter’s cut-off. This last bit is rather
unusual, but it gives the 3031 its characteristic ‘th-wap’ sound when accents are triggered.
FILTER CONTROL: This is a three position switch that selects which external control
signal will affect the filter’s cut off frequency. Set to VEL, the velocity will control the cut off.
This is good for those touch sensitive keyboard solos. Set to MOD, the modulation wheel will
control the filter’s cut-off. This is great for controlling filter sweeps from your sequencer or
master keyboard. The switch’s middle position removes any external control on the filter.
AMOUNT: The filter’s cut-off frequency can be modulated with an envelope generator. Thus
dynamic filtering is possible. By increasing the amount of envelope modulation, the cut-off
point is increasingly moved by the envelope generator. The generator itself is triggered by the
gate signal, and produces a decaying voltage immediately after being triggered. This produces
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