kLtz is a patch I wrote for Aure demonstrating one way I use smoothdelay, a variable delay line that does not have pitch modulation. The name is inspired by titles from artists like Aphex Twin and Autechre. After creating the initial patch, I then added control sliders, which ended up adding a lot of dimension.

The controls of the patch are the following:


As usual, the patch starts off with setting up the clock.

First, a 1-size ftable called trig is created for storing the clock signal.

 _trig 1 zeros

dmetro is the main clock source. The BPM is decided from p-register 0, and multiplied by 4 to make the clock sixteenth notes. bpm2dur converts the bpm to a duration in seconds to make it a suitable parameter for dmetro.

 0 p 60 155 scale 4 * bpm2dur dmetro

The output of dmetro is fed into a maytrig, whose probability is controlled by p-register 1.

 1 p 0.2 1 scale maytrig 

From there, the signal is set to the table trig via tset. Prior to that it is duplicated so that the clock signal also remains on the stack.

 dup 0 _trig tset 


The clock signal generated from the previous section triggers an exponential envelope. The attack and hold parameters are constants.

 0.0001 0.004

The final parameter is the release time. The release time is randomly generated with the sample and hold generater randh, picking release times between 1 and 30 milliseconds.

 0.001 0.03 10 randh tenvx

Filtered Noise

The noise is multiplied by the envelope generator.

 0.5 noise *

The cutoff frequency of the filter is controlled by a random line generator generating values between 500 and 4000. The rate of the random line is determined by p-register 3.

 500 4000 3 p 3 40 scale randi 

The resononace of the filter is also determined by p-register 3. This particular filter design has a resonance range of 0 to 2. This high resonance amount causes a lot of self oscillations. This is what causes the sinusoidal sounds.

 3 p 1.7 1.9 scale 

The last parameter of wpkorg35 is distortion amount.

 1.11 wpkorg35

Smooth Delay

smoothdelay is a double delay line that linearly interpolates them any time the delay time changes. This causes a delay line that can smoothly change delay times. Hence, the name.

The input signal is duplicated, one being sent into the delay line. The feedback of the delay line is determined by p-register 2.

 dup 2 p 0.1 0.99 scale

The clock signal is obtained from the table trig, and sent into a clock divider, turning the sixteenth notes into quarter notes.

 0 _trig tget 4 0 tdiv 

This signal triggers the triggerable random number genrator trand. The value of trand determines the delay time of smoothdelay.

 0.001 0.29 trand

The maximum delay time and the interpolation time (in samples) are the final parameters to smoothdelay. Is is then scaled and added to the dry signal.

 0.4 1024 smoothdelay 0.3 * +