# ER-301/Aliasing Triangle

## Applications

• Thru-zero FM synthesis
• LFO with sync capabilities

## Description

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.

## 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,

${\displaystyle {\text{f}}={\text{f0}}*2^{\frac {x}{1200}}}$

where ${\displaystyle x}$ 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.

### 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 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.

### 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.