ER-301/Sine Osc

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Applications

  • Additive synthesis
  • Thru-zero FM synthesis
  • Phase Modulation synthesis (PM)
  • LFO with sync capabilities
  • Pass through a limiter to create a square wave.
  • Waveshaper

Description

This unit is a full-featured sine oscillator with inputs for both exponential and linear FM, PM, feedback and an internal VCA on its output. The linear FM supports thru-zero operation.

Tip-bulb.png
Where are the controls to change the waveform? You don't need them. The replace command in every unit's menu is a more powerful and general alternative which lets you replace any unit with another unit bringing over values and sub-chains of similarly named parameters. This works particularly well for quickly and smoothly replacing this unit with any of the other oscillator units.


Parameters

V/oct

Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Pitch yes transpose (-3600¢ to 3600¢) logarithmic ratio

This parameter is used to transpose the base frequency up or down according to an incoming modulation value that is V/oct calibrated (typically one of the inputs from the ABCD matrix). In other words,

where is the value of this parameter (which is in cents). For example, if the base frequency (f0) is equal to 55Hz and this V/oct parameter is set to 2400¢, then the resulting frequency will be 220Hz (i.e. 2400¢ = 2 octaves which is 4x).

f0

Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Gain/Bias yes gain (-10,000 to 10,000)

bias (10 octaves above and below 27.5Hz)

frequency in Hertz


This parameter sets the fundamental frequency that is subsequently transposed by the V/oct parameter. Modulating this parameter corresponds to (thru-zero) linear FM.

phase

Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Gain/Bias yes gain (-10 to 10)

bias (-1 to 1)

linear


Sets the phase offset of the oscillator. Modulating this parameter is equivalent to PM (phase modulation). You can even set the f0 parameter to zero and put the oscillator completely under manual control via this phase parameter. This last case is also called waveshaping.

feedback

Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Gain/Bias yes gain (-10 to 10)

bias (-1 to 1)

linear


The feedback parameter determines how much of the unit's (pre-level) output should be used to self-modulate the phase offset. Increasing amounts of feedback causes the sine wave to morph into a saw-like or ramp-like waveform.

Sine-osc-feedback.gif

FYI: For low frequencies (<55Hz) and high feedback amounts (>0.95), the oscillator will turn chaotic briefly as it passes through zero.

Feedback-chaos.png

sync

Control Type Has Sub-chain? Sub-chain Parameters Behavior
Threshold yes threshold (-1 to 1) trigger


A trigger into this parameter will cause the oscillator to reset its phase accumulator to the value of the phase parameter. This is equivalent to the hard-sync on many oscillators.

Pitfall.png
This sync operation is not anti-aliased. So audio-rate triggering of this parameter will exhibit strong anti-aliasing artifacts which depending on the desired result could be a good thing or a bad thing.


level

Control Type Has Sub-chain? Sub-chain Parameters Fader Scale
Gain/Bias yes gain (-10 to 10)

bias (-1 to 1)

linear gain


This parameter controls an internal bipolar linear VCA on the output of the unit. It behaves exactly the same as the level parameter of a Linear Bipolar VCA unit.