and now, (taaa-daaa!) the metaAARDVARK! (Thanks Antonio Tuzzi!)
Sunday, September 2, 2018 at 12:53AM

Antonio Tuzzi, who designs and composes under the name of NYSTHI, has designed a new module for his extensions of the VCV Rack modular synthesizer ( based on the design of the Random Voltage Module from my Aardvarks IV box of 1975.  I sent him my Master’s thesis described in My History with Music Technology, part 2, where I describe the module, and give its specifications and circuitry (download it HERE), and he replied, faster than I could imagine, with the following module, the metaAARDVARK, which extends the possibilities of the original module quite wonderfully.

I wrote about an earlier version of Antonio’s modules HERE, but such is the pace of development of his project that he’s designed many modules since this.

With this module, we have (from top to bottom), outputs from the internal clock (it can run from 0.01 HZ to 8 kHz!), a very fine control frequency input, a readout of the resultant frequency, an external clock in, a voltage control clock-speed input and trimmer, a voltage offset (and CV input), a gain control (and CV input), a portamento (and CV input) control (which only affects the Smooth output), DAC controls (more on this in a moment) and outputs for the Smooth and Stepped outputs, and a Pulse output that allows only some of the pulse outputs from the internal clock through, depending on the knob setting. A fuller explanation of all the functions can be found HERE.

What makes this more than a simple Sample and Hold random voltage generator are the DAC controls.  You can select the number of bits in the output of the random voltage generator, from 2 to 10.  This will give you from 2 to 1024 levels in your random voltage output.  But you can also set a random amount of deviation from the ideal levels that a DAC should produce, per bit, from 0% (no deviation) to 20%!  Since I had (intentionally) used very dodgy resistors in the Digital to Analog Converters of the original Aardvarks IV, to get a different set of “random” voltages out of each random voltage generator, this control allows me to emulate that, and more.  Each time you adjust this control, you get a new set of random offsets applied to each bit of the DAC.  This gives me a LOT more control over the kind of output I’m getting, and also allows me to have each separate metaAARDVARK as a particular set of random voltage “found objects.” 

When combined with Antonio’s Scala Quantizer, this allows me to work with precisely chosen segments of microtonal scales, making random choices from the elements of the chosen range of the scale.

I talked about the Scala Quantizer in my Soundbytes article, but suffice it to say that the metaAARDVARK and the Scala Quantizer have become indispensable for my work with VCV.  Here’s a snap of a patch using both.  The metaAARDVARK supplies a trigger pulse to the AD Envelope Generator, and the Stepped output (shaped by the Voltage Offset, Gain, and DAC settings) controls the frequency of the Tiny Sawish Oscillator.  The Oscillator goes through the Wave Shaper, and the AD Envelope Generator controls both the amount of Waveshaping and the Amplitude of the Oscillator, through the VCA on the 4Mix.  The output of the 4Mix goes to the Audio Output.  A very simple patch, but the amount of control I can have over the pitch and rhythm resources of my chosen scale are immense, especially if you use the voltage control inputs for the Clock, the Voltage Offset and the Gain.

MANY MANY THANKS to Antonio Tuzzi for making this module, and for his ongoing work on the VCV Rack project.  I’m really very happy that I can now once again begin working on the implications of the (new extensions of the) random generation modules that I designed waaaaaaay back in 1975.  In this case, it’s true – everything old is suddenly and delightfully new again.

Article originally appeared on WARREN BURT (
See website for complete article licensing information.