Specifications

accurate sounds, and allows precise de-tuning. The Oscillator Slop parameter

allows subtle amounts of frequency drift. For larger amounts, use a random LFO

or white noise mod.

Pitch Wheel Range: 0…12 — Sets the bend range, in semitones, of the pitch

wheel. The setting is the range in the positive or negative direction. For

example, a setting of 7 lets you bend a note up or down by a fifth.

Mixer Parameters

Osc Mix: 0...127 — Enables the outputs of Oscillators 1 and 2 to be mixed in

varying amounts. A setting of 0 is equivalent to 100% Oscillator 1 and 0%

Oscillator 2. A setting of 127 is just the opposite. A setting of 64 is essentially a

50-50 mix of both oscillators.

Noise Level: 0…127 — Controls the volume of white noise mixed into the

filter.

Feedback Parameters

Feedback Volume: 0...127 — This controls the amount of audio from the left

channel of each voice fed back into that voice's mixer pre-filter. As the value

increases, so does the effect of the feedback.

Feedback Gain: 0…127 — Feedback Gain boosts the level of the feedback

signal and is interactive with and dependent upon Feedback Volume. If

Feedback Volume is set to 0, then Feedback Gain has no effect. (There is no

feedback signal to boost.) However, Feedback Gain combined with higher levels

of Feedback Volume can result in effects ranging from pleasing distortion to

squirrelly harmonic weirdness.

Low-pass Filter Parameters

Each of Tetra’s voices utilizes a switchable, 2- or 4-pole analog low-pass filter

coupled with a 4-stage (plus delay) ADSR envelope generator.

Frequency: 0…164 — Sets the base filter cutoff frequency over more than 13

octaves. This control steps in semitones.

Resonance: 0…127 — Sets the Resonance level of the filter. At high settings

the filter will self-oscillate in 4-pole mode. If the filter does not oscillate, switch

to 4-pole mode.

Keyboard Amount: 0…127 — Sets the amount of keyboard (MIDI note) to the

filter cutoff. A setting of 64 will step the filter one semitone for each note, 32

would be half-semitones, and so on.