ER-301/Aliasing Triangle

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  • Thru-zero FM synthesis
  • LFO with sync capabilities


This unit is a simple triangle oscillator with inputs for both exponential and linear FM, and an internal VCA on its output. The linear FM supports thru-zero operation.

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.



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).


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.


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 zero. This is equivalent to the hard-sync on many oscillators.

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.


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.