Forge-TME VHIKK X Eurorack Synth Voice Module

Experimental stereo synth voice/fx processor for Eurorack

The Vhikk twists, convulses and wails in a vortex haunted, spitting dirt and dust and time and raw energy.Rapid shadows, alien physics, pulsating artefacts, sometimes ridiculous, sometimes possessed. A window to an alternate reality. Engine room communications network phreak, phase splitting in the teardrop orbifold. The vhikk is a multi-algorithm sound source and processor capable of traversing sonic planes complex, raw, dense, electric, erratic, dynamic.

About Vhikk X

Vhikk X is a multi-algorithm experimental synth workshop specialising in (but not limited to) complex drones/basses, rich textures, dynamic sfx, and warped signal processing. It combines sound generation and effects processing into one module with multiple different algorithms.

The nature of Vhikk X makes it suitable for situations where a compact, ergonomic, and self-contained sound source/processor would be welcome – for example smaller modular systems, or large systems where a self-contained sound island with minimised cognitive overhead would be desirable.

Each combined position of the two toggle switches is a different algorithm, giving 9 in total per bank.

There are 4 banks as indicated by the 3 red lights between the toggle switches, giving 36 total algorithms.

Vhikk X expands on the original Vhikk technically and ideologically by offering more parameters, more algorithms, more CV inputs, and continuous control over architectural morphing and internal randomisation – all while retaining the ergonomy and interactive experience of Vhikk V1.

Vhikk X also introduces:

• 24-bit inputs and outputs
• Stereo inputs for audio processing
• VCA input for amplitude shaping without requiring an external stereo VCA
• Continuous control of input/output volumes with soft clipping and lots of gain on tap to drive next-in-chain modules and boost lower level input signals. [Can also take line level in and produce line level out.]

The improved signal path allows for Vhikk X to expand into cleaner and more dynamic sonic territory, while still providing means to twist and crush itself into dirty saturated mayhem. There have also been stereo imaging improvements, with algorithm tweaks to run in true stereo end-to-end.

Vhikk X has the ability to do firmware updates via the USB-C port on the side, supporting USB Mass Storage drag and drop [UF2 bootloader].

Using Vhikk X

Power/IO

The Vhikk X power connection is side-entry with a cutout in the main circuit board for cable clearance. Ensure the red stripe [-12V] is closest to the ‘RED’ label on the rear of the circuit board [red stripe down as viewed from behind]. The power input is reverse polarity protected.

Vhikk X has stereo outputs on the bottom right labeled L and R for left and right. The L output is normalled to the R output so linking a single cable from R will provide a mono sum. The stereo inputs at bottom left are normalled in software, so putting into a single input [either L or R] will work for mono signals. The long LED windows above the input and output jacks are for level-monitoring and display their respective signal levels – white for left [L], red for right [R]. The signal path for the audio inputs is algorithm-dependent and is detailed in the algorithm reference.

Encoders

In addition to the parameters present on the fixed-function knobs, the two central encoders can target a number of different parameters dependent on the current MODE. The active encoder target is denoted with white text labels, while the inactive labels glow red.

The most-used encoder target parameters [BASIS, TIME, SEED, SCAN] have associated light windows which give a visual representation of their current values.

The top button [MODE] will toggle between the two main encoder target states – BASIS + TIME, and SEED + SCAN.

The bottom button’s function is dependent on the current encoder target state:

• When the encoders are targetting BASIS + TIME – the bottom button engages encoder volume [VOL] control.
• When the encoders are targeting SEED + SCAN – the bottom button changes the currently selected BANK

[Note: the release firmware only contains a single bank of algorithms, so BANK selection is disabled until future firmware updates]

In volume control mode [VOL], the left encoder controls input volume, while the right encoder controls output volume. The text labels are disabled, since the lower LED windows are used to show current in/out volume levels and the upper LED windows are in/out clipping indicators.

The volume gain ranges are detailed in the specifications below, but are suitable for use with many different signal levels, both in Eurorack systems and directly with line level equipment. The signal path has plenty of headroom and is designed to soft-clip at each gainstage.

State-saving

The encoder-targeted parameters are all saved internally to retain their values through power-cycles. There is an internal delay for wear-levelling, so any parameters which are unchanged for approximately 30 seconds are saved.

SEED and SCAN are saved per-algorithm, and volume levels [VOL] are saved globally. BASIS and TIME can be selectively saved globally or per-algorithm.

Holding down the top button [MODE] while powering on the module will enable per-algorithm saving, while holding down the bottom while powering on button will enable global saving. This selection will be remembered until the next time it is changed. Global saving is enabled by default.

Global saving is intended for situations where it is convenient to retain e.g. tuning and synchronised delay times across different algorithms, while per-algorithm saving allows for each algorithm to retain its own copy of these parameters.

VCA/CV normalling

The CV input ranges are detailed in the specifications below. The 5 CV inputs in the bottom centre have their own associated attenuverters, while the remaining CV inputs are summed with the value set by their associated panel control.

The VCA input targets an internal stereo VCA for amplitude control without requiring an external stereo VCA. This also allows for the VCA to e.g. be placed before delay/reverb sections. The location of the VCA in the signal path is algorithm dependent and is detailed in the algorithm reference.

With nothing in the VCA input, an offset equivalent to +5V is present. A +5V external CV will open the VCA fully – voltages above this will overdrive whatever is following the VCA in the signal path.

The VCA input and the CV inputs with attenuverters have software controlled normalling to allow for flexible CV control even with minimal physical patching.

If a CV goes into the MORPH input, it will be normalled to the 4 other inputs [BASIS, FIELD, TIME, FORM] which will then pass through their respective attenuverters.

If a CV is goes into the VCA input, it will be normalled to the 5 other jacks, overriding the above normalling.

If nothing is in both VCA and MORPH, a small offset will be normalled to MORPH, BASIS, FIELD, TIME and FORM to allow the use of the attenuverters as fine-tune controls.

All physically accessible parameters have CV inputs except for the volume controls and SEED – SEED is intended to be a very wide-ranging parameter designed for manual control. In testing, the VCA input proved more useful than a SEED CV input.