Slew Limiter

1. Time Knob Sets the slew rate.
2. ÷100 Switch Makes the slew rate quicker by a factor of 100, to process audio signals.
3. Skew Knob Skews the slopes. When centered (double-click), rise and fall time are the same. When turned counterclockwise, rise time becomes shorter. When turned clockwise, fall time becomes shorter.
4. Reset Input When Reset is triggered, the output immediately jumps to the input voltage.
5. Main Input Signal that will be slew-limited. Typically a gate, LFO or some kind of envelope.
6. Lin Output Signal slew-limited with a linear slope.
7. Exp Output Signal slew-limited with an exponential slope.

Overview ⚓︎

A slew limiter limits the rate of change of its input signal, or, in other words, softens the sharp edges of the signal.

Our take on this unassuming utility module packs a lot of punch. It simulates two fully independant slew-limiting circuits: one linear and one exponential.

The Slew Limiter is very similar to the Glide module. The Slew Limiter is better adapted to LFO or envelope signals, while the Glide module was designed to be used for pitch signals.

Usage ⚓︎

Slew-limiting CV Signals ⚓︎

The Slew Limiter will typically be used to process CV signals. For example, it can reshape envelopes or LFO signals, or soften a gate to use it as an envelope.

Connect the CV signal to be slew-limited to the In jack, connect the Exp or Lin jack to the desired modulation target, and adjust the slew rate with the Time knob. Make sure that the ÷100 switch is off.

Slew-limiting Audio Signals ⚓︎

To use the Slew Limiter on audio signals, activate the ÷100 feature so that the range of the Time knob works with audio frequencies.

The Exp output will work as a plain 6 dB/oct low-pass filter when Skew is centered. Turning Skew clockwise or counterclockwise will introduce a kind of fuzzy distortion to the signal.

The Lin output is harder to describe. It does an amplitude-dependent low-pass filtering where louder signals are filtered more, while also always introducing distortion. The Slew knob will adjust the timbre of the distortion.

With some careful calibration, the Lin output can be used to waveshape square waves from the Classic VCO into a trapezoidal waves with up and down slopes adjustable with the Skew knob. For pitch tracking, connect the Keyboard Pitch to the Slew Limiter Time and set the attenuverter to -100% (slew time must be reduced when the pitch rises).

In Depth ⚓︎

Time ⚓︎

The Time knob adjusts the slew rate. It displays an approximate value in seconds, but the meaning of this value is different for the Exp and Lin outputs.

Effect of Rate on Exp output

For the Exp output, the value of the Rate knob is the time it takes to reach within 99% of the voltage variation on the input. If the input quickly jumps from 0V to 10V, then the output will have reached 9.9V after the given time.

Effect of Rate on Lin output

For the Lin output, the value of the Rate knob is the time it takes to change the output by 10V, which is the typical peak-to-peak voltage for gates, envelopes and oscillators in Multiphonics. If the voltage on the input jumps from 0V to 1V, it will only take one tenth of the Rate time for the output to reach 1V.

÷100 Switch

The ÷100 switch divides the posted time by 100. This makes the slew rate quicker, which is perfect when the module is used to process an audio-rate signal.

Skew ⚓︎

The Skew knob can make the slew rate faster for either rising or falling slopes.

When Skew is centered (default double-click value), the rate is the same for upwards and downwards slopes.

From the center position, the upwards slope time will become shorter as the knob is turned counterclockwise, and the downwards slope time will become shorter as the knob is turned clockwise.

Reset ⚓︎

When the Reset input is triggered, the output will immediately be set to the input voltage, bypassing the glide algorithm.

This is a one-time event that happens when the input goes from low (0V) to high (10V). Keeping the input high will not disable the glide effect.

This feature may be used to generate very simple pluck envelopes by connecting a trigger signal to both the In and Reset inputs.