Modules for Voltage Modular


Contrary to purple popular belief, Aarpo is not related to the Marx Brothers.


Aarpo is an arpeggiator offering four repeatable patterns, each with four direction options plus three random patterns, across one to four octaves. It can run off an internal clock or sync to an external one and has a variable gate length.

It also has a groovy, tiny pattern display - gimmicky and useful in equal measure!


Pitch and Gate In

A standard poly input pair. This is the raw material for Aarpo to chew on!


A standard trigger input. A rising edge on this input randomizes the Direction, Type and Octaves knobs.

Clk In

An (optional) external clock input. Every rising edge on this input advances the arpeggio by one note. Connecting anything to this input disables the Tempo knob and duplicates the incoming clock to the Clk Out socket.


A standard trigger input. A rising edge on this input resets the internal clock generator so that the next note triggers immediately. 


Clk Out

If no external clock is connected then this output sends out the internal clock, set by the Tempo knob. If an external clock is connected then this output is simply a copy of that clock.

Pitch and Gate

A standard pair of mono outputs, sending out the current note of the arpeggio.



Four direction options: Up, Down, Up and Down, Down and Up. Not used for the three random types.


Seven pattern options: Normal, Exclusive, Scatter, Bass, Random, Shuffe and Snapshot. Combines with the Dir knob to make the final pattern. See below for details


The number of octaves to use from 1 to 4.


Sets the speed of the internal clock generator in Hz, from very slow to way too fast.


Sets the length of the output notes in milliseconds. If you are running at a fast tempo and not hearing all the notes you may need to reduce this length.

Pattern Types and that Display

There are seven different pattern types. The first four each have four variants set by the Dir knob. The Dir knob does not affect the three Random modes, which means that Aarpo offers a choice of 19 different arp patterns. 

The "mini display" near the bottom of the module gives an indication of the selected pattern. This does not show the actual notes, just an indication of the pattern of notes for a four or five note input chord.


Each note is played in order low to high, or high to low, or both, as set by the Dir knob.


This is the same as Normal except it avoids double notes in the "Up Down" and "Down Up" modes.


Notes are played alternately from the two ends of the input chord and work their way "middle". A five note chord in "Scatter Up" mode will play the notes in this order: 1-5-2-4-3. Try it across two or three octaves at a fairly fast tempo.


The lowest note is played in between evey other note. A five note chord in "Bass Up" mode will play 1-2-1-3-1-4-1-5.


Plays random notes for the input chord. This can result in two or more repeats of the same note, which brings me to....


Another random mode but this one will not repeat a note until all the notes have been played. So it shuffles the input notes, plays them all then shuffles them again. 


The third and final random mode. This is identical to shuffle except that the shuffled pattern stays constant for as long as the input notes are held. This is my favourite of the random modes and is arguably the most pleasing to the ear, because you get a chance to tune in to a repeating pattern.

Video and Preset

Download the Preset