Mod Squad: Harvestman Piston Honda MK II

AMONG THE companies creating Eurorack modules, The Harvestman is one of the few that doesn’t strive for analog warmth.
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Patch your modular into another dimension of sound

The Piston Honda MKII is a digital wavetable synth with a unique interface that lets you go through its 4,096 waveforms as if they were laid out in a 3-dimensional space. AMONG THE companies creating Eurorack modules, The Harvestman is one of the few that doesn’t strive for analog warmth. The brainchild of Seattle-based designer Scott Jaeger, the Harvestman puts digital circuits under CV control to create modules that urge you to explore timbral extremes, while retaining a measure of subtlety in the process.

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Recently, Jaeger released a greatly expanded version of his digital wavetable oscillator, the Piston Honda MKII ($495), which features a completely redesigned interface, expanded memory, and improved sound quality. The updated module provides 16 waveform ROMs, each of which holds 256 8-bit waveforms evenly divided into 16 banks. However, the new design cleverly configures these waveforms into a 3-dimensional space using three axes, where z is the ROM, y is the bank, and x is the specific waveform. Using faders for each axis (along with dedicated CV inputs and bipolar knobs), you can access any of the available 4,096 waveforms linearly or nonlinearly from anywhere within in the 16x16x16 space.

The ROMs include banks of noisy, additive, and chordal waveforms designed by Jaeger, as well as sounds from Wiard Synthesizer designer Grant Richter (creator of the Waveform City wavetable synth), David Hylander, Chris Novello, Michael Firman, Matthew Davidson, and Jordan Bartee. Overall, the waveforms range from simple, harmonic-based sounds to dense and gritty textures.

Six of the waveform ROMs (z-axis banks 2 through 7) are doubled in banks A through F, which are meant to be replaced: Users can add their own waveforms using the Piston Honda expander (available separately), which plugs into the module’s rear panel. The Piston Honda MKII accepts 8-bit waveforms created with Wave256, a Windows-based program.

Sounds from Within The 1V/oct input accepts 0-8V, giving the Piston Honda MKII an 8-octave range. Course and Fine tuning controls and a hard-sync input are provided, as is a switch that drops the oscillator into the LFO range.

Individual inputs are available for through-zero frequency modulation and CV control (the latter using 0-5V DC signals) of the internal oscillator. The two inputs share an attenuverter, a center-detented knob that attenuates the signal from the CV input while simultaneously acting as a bipolar control for the FM input.

One of the highlights of having a wavetable synth is being able to use it as a waveshaper to process external signals. In addition to featuring an external audio input jack (with an associated gain knob and CV input), the Piston Honda MKII has an independent output for the external signal. That allows you to process external sources through the same wavetable that is being used by the internal oscillator, but with discrete outputs for each. You can further change the sound depending on the setting in the Morph Discontinuity section.

Morph Discontinuity Another exciting feature on the Piston Honda MKII is the ability to smooth out the steps as you move between waveforms. This makes the waveforms sound as if they are morphing into one another. When the Morph Discontinuity’s Mode button is green, you can control the amount of smoothing between steps of the internal sound; when the button is red, morphing is applied to the external audio’s processing (while, at the same time, the internal sounds are played back at a higher resolution).

The Axis Select button determines the combination of axes to which smoothing is applied. The slider for each axis has an LED on the end: When it is lit, you can adjust the morphing between steps of that axis. When the Morph Discontinuity knob is fully clockwise, you’ll hear stepping. Turn it fully counter-clockwise to get a morphed-sound response between steps. The associated CV input (with attenuator) lets you continuously alter the degree between stepped and smooth behavior—nice!

Overall, the Piston Honda MKII provides an elegant way to extend your system beyond the traditional timbral reaches of analog subtractive synthesis. And with the ability to load banks of customized waveforms, this module provides an almost unlimited palette of colors, especially once you put the module’s extensive modulation capabilities to work.