Tag Archives: reaktor

Reaktor Effect: Random Multitap Delay/Shuffler


The Random Multitap Delay is a delay effect that randomly, continuously changes the delay time between the input and output. The delay times are based on musical note durations – ¼ note, ? note, ? note triplets, etc.  My goal was to use random processes in a way that preserves rhythmic integrity — the output stays in time with the input and any other rhythmic elements in the music.

Internally there is a multitap delay, whose delay time is a multiple of the current rhythmic division. If you select ? for the tap length then the first will delay ? note, the second 2/8 , the third ? etc.

The effect switches randomly between the delays over time, effectively re-arranging the input signal in time, shuffling it up.  This is particularly effective on drums, because it will generate an endlessly varying rhythmic pattern that will still add up to the ear.

There are two identical delays for the left and right sides of the stereo signal. Since the current delay tap is chosen randomly, the right and left signals will be different even if all the controls are set the same.

It’s actually harder to describe what the effect does clearly than to understand what it does by tweaking the controls, and hearing the results.

In Use

There is a hierarchy of chaos in the controls of the Random Multitap Delay.  I’ll list them from least chaotic to most chaotic:

Sync and Stepped On

With both sync and stepped set, every rhythmic division, one delay is selected.  For example, if 1/8th is selected for tap length and 1/8th is selected for S&H, every eighth note a different delay tap is chosen.

Sync On, Stepped Off

Every rhythmic division a fractional value is chosen, that will select a blend of 2 delay times.  For example, if the tap length is 1/8th and selection value is 3.5, you will hear a 50/50 mix of the 4/8ths and 5/8ths delays.

Sync Off, Stepped On

The delay tap selection varies continuously, based on Rand Speed, but only one delay tap is selected at a time.

Sync Off, Stepped Off

The delay tap varies continuously at Rand Speed, and a mix of two delay taps will be heard all the time.

The meter and numeric display below the stepped button shows you how these controls interact.  They will show you exactly which delay tap is playing at a given time.  The delay taps are numbered 0 to 7, since I’m a computer programmer ;-)


Tap Length

This chooses a base delay time for the multitap delay.  These are standard musical divisions of time — ¼ note, 1/8th note, dotted 1/8th etc.


Controls the rate of change of the delay taps.  Every ¼ note (for example) a new delay tap is selected at random for the output.


When this is on, the delay time is selected based on the setting of S&H.  When it is off, the delays are switched between continuously at the rate specified by Rand Speed.

Rand Speed

Chooses the speed at which the delay selection changes. The numeric value below the knob gives the speed in cycles per second/Herz.


Determines whether the delay selection is stepped (i.e. selecting just one tap at a time 0, 1, 2, 3…) or continous.  If Stepped is off,  you will hear a mix of two adjacent delay taps most of the time ( 0.3, 1.7, 2.1 …)


Controls the level of feedback for both the left and right delays.

Cross FB

Controls the amount of the left delay that is fed into the right delay, and vice versa

L FB Mode/R FB Mode

Selects the filter that is included in the feedback path of the delays. High Pass, Band Pass, Low Pass etc. ‘Bypass’ is also an option, which removes the filter entirely from the feedback path.


The difference between the left and right feedback filter cutoffs.  At 12 O’Clock, L & R filters have the same cutoff. As you rotate left, the left cutoff reduces, and the right cutoff increases.  As you rotate right the left cutoff increases and the right cutoff decreases.


Feedback filter frequency


Feedback filter resonance.

How to make Reaktor Knobs Automatable in Ableton Live

So the target demographic for this post is the intersection of three sets:

  • Ableton Live Users
  • Reaktor Users
  • People wonky enough to try and automate VST plugins with envelopes.

Still with me? OK.

I was contacted by an Internet acquaintance because he wanted to use the Reaktor Effect that emulates the Roland RE201 Space Echo, and he wanted to automate it with envelopes.  There are two places you can do this — In the ‘Session View’ on a per-clip basis, and in the ‘Arrangement View’ on a per-track basis.

The way you do this, in both cases is by selecting the plugin instance  from a pull down menu of Automatable Things, and then select the parameter to automate from a separate pull down menu just below the first.  In the case of the ‘Session View’ there’s a first step — select a clip, then on the far left hand side of its properties, click on the little ‘E’ in the bottom row.

In this case, all the parameters of the RE201 were just invisible.  I asked about it on the NI Reaktor Forum, and got this answer.

So I wrote back to my friend with this advice, which may stand you in good stead should you ever get into this sticky situation:

Live before rev 8 only recognizes the first 128 automation parameters.  The parameters (i.e. changeable knobs and controls) each has an ID that’s unique per instrument.  These IDs get assigned as an ensemble is created, and if you delete a control, the ID isn’t re-used.

When it comes to Automation, the parameters are exposed by the standard VST mechanism, with each Reaktor parameter being the Base ID for the instrument, plus the ID of the control.

In the case of RE201, the base parameter was 500-something, so all controls were invisible to Ableton Live.

If you look in the Reaktor Instrument Properties, click on the control routing tab. (the two little boxes with an arrow between them).

At the bottom, there’s an ‘Automation’ section.  Do two things:

Pull down the ‘IDS’ menu, and select ‘Instrument Up’ until the base ID is zero. Then pull down the ‘IDS’ menu again and select ‘Sort and Compress IDs’

This will make all of the controls in the RE201 visible in Live. Honest to God.