Every kind-of, sort-of, roughly two years*, the KVR Audio site holds a contest known as the KVR Developer Challenge.
* Since its debut in 2006, the KVR DC has been held in 2007, 2009, 2012, 2014, 2016, 2018, 2021, 2023, and now 2026.
For the Challenge, plugin and soundware devs from across the globe design and build new and creative synths, effects, sound libraries, and tools for KVR forum users to evaluate and vote on. The winning developers receive cash prizes, bragging rights, and the endless adulation (and new feature requests) of the KVR crowd.
And everyone gets to try out a bunch of new plugins, because all KVR Developer entries are free and must remain so throughout their development. It’s free-plugin Christmas in August! We’ve picked out a handful of our – and KVR readers’ – favourites to highlight below.
(For all results and to download the entries, see the KVR DC26 main contest page.)
Always Bank on Fog
Vain Audio have been developing plugins for the past few years, with several interesting and innovative effects (including several free plugins) featured on the Vain Audio website.
That lineup includes Fogbank, Vain’s “expander and multiplier” plugin submitted to this year’s KVR Developer Challenge. At its core, Fogbank is a multi-effect unit with three effect slots; each slot can hold any of six distinct effects: an Allpass filter, Balance (volume and panning modulation), Delay, Diffuser, Distortion, or classic Filter. Each effect includes basic controls like Amount, Feedback, Time, and Mix. But that’s the easy part.
The really interesting bits of Fogbank are the modulators, of which come in three flavours. First, six LFOs with standard (and somewhat non-standard) shapes, with dials for Frequency and Scale. Next are the four macro knobs at top right, ready to modulate as many factors as you like. But the real stars are the polyphonic modulators, displayed as three geometric shapes above the effect controls at bottom.
Each of Fogbank’s poly modulators includes a number of points, corresponding to the VoiceCount specified at top centre. Fogbank duplicates incoming audio up to sixteen times and sends each copy separately through the gauntlet of effects before recombining the audio. Each copied “voice” is represented by a point in each poly modulator shape. Those shapes can be manipulated with the controls in the Transforms section to Rotate, Swirl, Warp, Scale, and otherwise fold and mangle in nearly any conceivable fashion. The X and Y coordinates of each point can then be used to modulate the effect parameters, giving different values for each of the duplicated voices.
At the same time, any of the LFOs and macros can be assigned as modulators to X or Y coordinates of any of four possible transformations for each of the three polyphonic modulators, further morphing and stretching the shapes and coordinates. Add a level of modulo-inception where each LFO or macro can modulate any LFO’s Frequency and Scale and Fogbank provides a veritable playground for building unique and ever-shifting modulated effects.
Twice as Gneiss at Zero Price
Hvoya Audio and developer Eugene Yakshin are perhaps best known for the free, quirky, and captivating Ribs granular synth released a few years ago. As the Hvoya website indicates, they’ve developed additional intriguing tools since then, including their DC entry, Gneiss.
Gneiss is essentially a filter – or more specifically, a “morphing multi-stage filter with colorful chaos”. Gneiss’ two pre-filters are resonant state-variable filters, which feed into a Moog-style transistor ladder filter in the final stage. If you like, they can play nicely together and gently colour whatever you pass through – but where’s the fun in that?
The “chaos” bit is where Gneiss really shines, and it isn’t difficult to find. The main “All” tab provides an impressive array of controls to sculpt the various filters’ behaviour, from the pre-filter cutoffs (A hz and B hz) and resonance (A res and B res) to the same params for the main filter (M hz and M res, respectively), drive, damping threshold, H(old), R(elease), and the “chaos engine” break, with several parameters of its own.
As the very helpful Gneiss user manual (available from the KVR Gneiss plugin listing) explains, Break is “a family of nonlinear shapers folded into the ladder’s feedback – turn it up and the whole system tips out of ‘filter’.” This provides Gneiss – and you! – with myriad creative opportunities to push, swell, tame, taunt, and unleash the resulting feedback-driven chaos.
For me (or anyone else who’s also a bit over their head with some of Gneiss’ more technical controls), the plugin includes two killer features. First, the “User” tab allows you to customise your own interface with just the controls you use, to reduce some of the complexity.
And second, really for everyone, is the “Morph” tab, where five pre-configured sets of parameters (“morph points”) are represented. These can be moved around, along with a “user point” that controls which points have the most influence. Drag the user point to taste, cluster the morph points as you like, or select one morph point and adjust its parameters – all are quick and creative ways to coax delicious filter-based grit, sizzle, and chaos out of Gneiss.
Come with Me If You Want to Orb
The audiodev.blog site is both the blog of audio programming enthusiast and freelance developer Matthijs Hollemans and the home of several interesting plugin projects, including the Krunch Saturator, The Kiss of Shame tape emulation, and a revived and modernized s(M)exoscope visualiser.
Hollemans’ latest project and DC26 entry is the Orbinator synthesizer, a wavetable synth with a twist. Or actually, a curve, in circular form. Lots of them, in fact.
The controls at the bottom of Orbinator are pretty straightforward. At centre, Tuning adjustment and standard envelope ADSR controls. On the left, toggles to Sync tempo to host, add Unison voices, and Smooth movement. On the right, further controls for pitch Bend, Vel(ocity) sensitivity, speed (Spd), and Out(put) level. All the basics you might expect in an everyday wavetable synth.
Ah, but this is the Orbinator, inspired by the mechanics of scanned synthesis and dynamically generated rather than static wavetables. As the name suggests, the Orbinator is based on orbs, which can be placed with a double click in the main central area. Up to eight orbs can be placed, then moved or resized as preferred. Dots, connected by a virtual string, will circumnavigate the orbs, one dot per each, with independent speed controls for each dot.
As Orbinator’s included presets demonstrate, this relatively simple system can be manipulated to produce a variety of sounds, from slow and evolving pads to leads and basses. Sometimes the fun is in tweaking the orbs just so to dial in a certain sound, and sometimes it’s in nesting or overlapping orbs just to hear the results. Orbinator isn’t intended to dazzle with a wealth of parameters or incredible depth. But as a creative, novel, and downright fun way to sling around wavetables, Orbinator is right on target. Circle gets the square.
Pining for the Plugins
Despite their somewhat foreboding name, Darkpalace Studio develop some of the most cheerfully colourful effect plugins available, as displayed on the Darkpalace website. Their Developer Challenge entry Parrot, a multi-modal delay (and more), is no exception. It also won third place in the DC26 voting, so congratulations to Darkpalace Studio!
Parrot is a multi-band multi-effect with many multi-creative multi-uses. Each of three frequency bands can be specified, shaped, stretched, and overlapped by dragging back and forth (to change the frequency range) or up and down (to change the width/Q) on each coloured peak in the main window section.
Below that, each band can be associated with one of (currently) eleven effects, including Tube saturation, Pitch Shift, BBD (bucket brigade delay), Flanger, Flutter, and (new in a recent update) Sample Rate.
Parrot provides intuitive controls that apply no matter which effect(s) are active. Among these are individual per-band frequency range and Q controls, adjustable peak Slope, Gain, Feedback, and Balance (i.e., panning) options, Time selection (host sync’ed or free), Mix slider, and an XY pad to control the two most relevant aspects of the current effect. Rate and Depth for the Chorus, for instance, or Amount and Skew for the Bitcrusher.
With a delay in each slot, Parrot becomes a creative and potentially wild multi-delay, with different frequency ranges bouncing and pinging at offset rates, feeding back on themselves in complex patterns. But as Darkpalace Studio suggests, bypass the delay entirely, if you like. Overlap Freq Shifts or Dispersers with different parameters and modulate the peaks back and forth for entirely different styles of effects. Go a little crazy. It’s a jungle out there, and this is one parrot that’ll squawk any which way you like.
It’s Always the Quiet Ones
As the Quiet Audio website says, they create “plugins, samples and apps for relaxing music, meditation, ambient, lo-fi and field recordings”, and they’ve done so quite deftly for a number of years. While Quiet’s Developer Challenge entry, Reverie, has a reassuringly calm name, it can get more… rambunctious. If that’s your thing.
Reverie is an effect plugin with two engines that can work together in peaceful harmony or separately in (presumably contemplative) isolation. The main engine is a configurable bank of Karplus-Strong-modeled strings that act as a resonator for whatever audio is passed through, with corresponding controls on Reverie’s “Main” tab.
The resonator controls range from basic characteristics like Density (from a single string up to twenty-four), Voice (string material), and Dry/Wet controls to Damp(ening), Spread, Decay, Detune, and other parameters. Speaking of detune, Reverie also allows the string bank to be tuned to a specific Root and Scale, including several microtonal options. A “Shape” section includes high- and low-pass filters, Drive, Bloom, and other useful tools.
Reverie’s second engine is an “audio-reactive sampler”, found on the “Texture” tab. Here, you can import a sample, set a start position and Loop direction, and choose a Mode – Trigger to play from the selected position when the incoming audio reaches an adjustable volume Cutoff, or Flow, to continuously scan through the sample and only play when the Cutoff is reached, whatever position the play head is at. Either way, controls including Attack, Tune, Pan, Variation, and Pitch Flw (follow) provide ample opportunity for creative mangling and experimentation.
Back on Reverie’s main page, the Excite option dictates whether the strings resonate based on incoming audio, the Texture sample, or both. With an onboard customisable modulator, reverb, delay, and many other sound-shaping parameters, Reverie’s effects can range from gentle soothing resonant accents to cross-talking jangled chaos in the span of a single mindfully observed breath.
Better Scintillate Than Scinti-Never
Last but not least – and indeed, first as the overall winner of KVR’s DC26 – is Scintillate, the debut plugin from Sweet Audio, founded by CrispyTuner developer Marius Metzger, and Signalsmith Audio. The specs suggest Scintillate is a spectral reverb plugin, but the devs bill it as a “Sparkle Engine”. And they won first prize, so who am I to argue? Sparkle Engine, it is!
In terms of controls, Scintillate is straightforward, intuitive, and efficient. The upper half of the interface (save the title bar with a presets menu and Undo and Redo buttons) represents the incoming audio frequencies with the “sparkles” being created in a pulsing aurora above. Low Cut and High Cut lines can be dragged from either side to limit the range where sparkle creation is allowed.
What are these “sparkles”, exactly? Best I can tell, they’re little bits of spectral stardust flecked off at specific frequencies of the audio passing through, possibly semi-randomly. There isn’t much specific info on the details from the devs, but Scintillate does provide controls for the Rate, Decay time, and Density of sparkles under the aptly-placed “Sparkle” header at centre.
You’ll also find a “Reverb” section at left, with tail Length, Tone, and Shimmer dials; and, at right, Width and Mix controls. Other than a footer with handy links to the developer websites, automatic tooltips, and GUI resize buttons, that’s all you get.
It’s also all you need, as the included presets demonstrate, to coax everything from traditional reverbs to undulating sonic washes to ghostly swells and trippy sci-fi sound effects out of Scintillate. Treat it as a reverb, a creative tool, or the Sparkle Engine it was sent into this world to be. In any case, you’ll likely find this plugin scintillating, as did many KVR voters.
