I’ve been tinkering with VST software since the early 2000s. Over the years, I’ve watched as many wonderful instruments have come and gone. Sadly, most of them are obsolete by today’s standards, and few have managed to hold down a strong reputation. Fortunately for KV331 Audio, SynthMaster is among the latter of those two categories.

Upon first glance, SynthMaster might seem fairly underwhelming, but I assure you, it’s a beast. I’ve used instruments selling for at least twice as much that feel like Cracker Jack prizes compared to this monster. But don’t be frightened by its enormity. SynthMaster is actually very user friendly. That being said, there’s a LOT of power under the hood, so pour yourself a cup o’ Joe. We’re going in…

The Review

First, you have two Layers, similar to many “dual core” synths like Omnisphere and Hybrid 3 with parts/sides A & B. Within each of these two layers are five View tabs that provide access to a fully interactive block diagram of the routing structure with global controls, a versatile arpeggiator and three pages of effects including a powerful Distortion module with a drawable curve and two shelving EQs, a LoFi (bitcrusher) module that features sample rate reduction with a simple resonant filter, an Ensemble effect with eight voices and two LFOs capable of modulating the delay and/or the space between each voice, a Phaser module with up to sixteen stages, and a parametric EQ with a 12-48 dB lowpass and highpass filter and low/high-shelf frequency bands, each with a 6 dB slope.

And those are just the effects available within each of the two layers! I haven’t even covered the global effects, but for now, let’s stay within the layer structure. Up to eight unison voices are available within the Layer tab with controls for Detune Spread, tuning the unison voices apart, Pan Spread, distributing each unison voice equally throughout the stereo field, Velocity Spread, varying the velocity of each unison voice, and a Velocity Error knob, which I haven’t been able to find any documentation for; I scoured the Quick Start Guide to no avail and did a fair amount of research online. Whatever is meant by the use of the word “error” is obviously specific to MIDI note velocity. There are also eight unison voices for each of the four oscillators, and if you times that by the number of global unison voices available in each of the two layers…altogether, that’s 256 unison voices!

See also: FXpansion Strobe2 Review!

Another important thing to keep in mind is that phase/frequency and amplitude modulation are actually built directly into the routing structure itself. With exception of Vector and Audio In, there are options for routing phase/frequency and amplitude modulation from within each oscillator window, with four dedicated Modulators that can be combined in several interesting ways, and you can also modulate the Modulars and determine the frequency in semitones or integers (numbered harmonics).

Each layer has two oscillators with five algorithms: Basic, Additive, Wavescan, Vector and Audio-In. The Basic oscillator features the usual suspects, with basic waveforms i.e. saw, square, etc. But one thing that really tickled my fancy is the ability to import WAV/AIFF files and then save them as SFZ instruments in the “UserSamples” file within SynthMaster’s internal folder structure. You can even drag and drop audio files directly into the oscillator window, saving you the hassle of manually navigating to each folder location within the file browser.

A cluster of eight basic oscillators with assignable waveforms and/or SFZ instruments appear within each Additive oscillator, with controls for Volume, Pan, Detune, Tone, Frequency partials in relation to the root note (or in semitones) and phase inversion buttons. Of course, it’s not the most powerful additive engine, but you can still make some pretty cool sounds with it.

The Wavescan oscillator is similar to the wavetable oscillator in U-he Zebra 2, which can seamlessly morph between sixteen single-cycle waveforms. Of course, you can’t draw your own waveforms within the oscillator, and you can’t import wavetables directly, but you can build your own wavetables and then save them in the folder structure, which is a little tedious, but by no means a deal breaker.

Not only is SynthMaster a powerful semi-modular workhorse, it’s also a great rompler, especially when the Vector oscillator is put to good use. I took the liberty of importing some pad sounds I made myself into the oscillators in each of the four corners and faded between them with the XY cursor as a goofy-looking grin washed over my face. I’ll definitely be making some huge sounds with that.

Unfortunately, for whatever reason, the Audio-In oscillator is clipping well over 0 dB when I load “SynthMaster2FX.dll” into a send channel receiving audio. First, I thought it might have something to do with my buffer settings, so I decreased the buffer size in my DAW, which resolved the clipping issue, but the audio was severely distorted. I’ve tried all kinds of routing configurations with no success. Although, regarding SynthMaster’s overall usefulness as an effect plugin, the Vocoder seems to function as intended, so whatever the problem is, it’s exclusive to the Audio-In oscillator.

Now, before I move on, I’d like to go into more detail about the arpeggiator, which is actually very sophisticated. You have the usual modes: Up, Down, UpDown, DownUp, etc. But there are also controls for Velocity, the Duration of each note, Slide, Swing, Hold, a Chord Mode where all notes are played simultaneously, and an Arpeggiate Mode, which is really special because you can trigger sequential increments and decrements for each individual note you press, and you can also determine the length of each note by simply dragging your mouse to the left or right. Another thing that put a smile on my face is that you can adjust the level of each step by moving your mouse wheel.

Of course, no hybrid synth would be complete without a handsome variety of filters, and we’re in no short supply with two filters for each layer in two basic flavors: Digital and Analogue. Also, within each of the two filters (in each layer) is a distortion section with a drawable curve and a PreGain knob boosting the filter’s input. The Drive knob boosts the filter’s output, which is fed into the Limiter with an internal envelope follower, allowing you to “hard clip” the resultant signal.

With exception of the Comb filter, both digital and analogue algorithms include the same filter types: low/highpass, bandpass, band-select, low/high-shelf, peak, multi-mode and dual multi-mode. I admit, I have a soft spot for comb filters, which can be used as a resonator effect to generate percussive sounds or plucked string instruments i.e. Karplus-Strong physical modelling synthesis.

Also, there’s a Filter Structure option within the Layer tab with three basic routing configurations. In Split mode, the input of both filters are exclusive to each of the two oscillators. In Parallel mode, both filters are receiving combined signals from both oscillators, and their outputs are mixed together. In Serial mode, the first filter’s output is sent to the second filter’s input.

Below the filter section, we have fourteen additional modulation sources, including four ADSR Envelopes, two Two Dimensional Envelopes, two Multi-Stage Envelopes, two Voice LFOs and four Keyscalers… and those are just the modulation sources within each of the two layers!

Now, let’s go into the global Synth LFO page, with four independent LFOs having six basic shapes: Sine, Triangle, Square, Saw, Step and Glide. Of course, I don’t need to explain the first four, but the Step and Glide LFOs are nearly identical except for one distinct difference: In the Step LFO, the “slope” handles only drag downward, whereas in the Glide LFO, the slope only moves upward, which is a little disorienting at first because you have to move your mouse toward yourself in order to move the slope handle upwards. I don’t know why they made it this way, but with a little practice, you’ll get used to it. The Step LFOs are perfect for sequences, and the Glide LFOs are very useful for smooth transitions. I’ve already saved a few “Random” presets for future use.

But wait! There’s more! Let’s not forget about the global FX page with a routing matrix and two global send busses. Earlier I mentioned the Vocoder, which offers everything we’ve come to expect from any common garden variety vocoder, with the usual multiband filter and envelope follower, but you can also use each of the sixteen bands as individual modulation sources!

I don’t really have to go into much detail about the remaining five effects: a Compressor, Chorus, Tremolo, Echo (delay) and Reverb, which are all somewhat generic. However, I can’t help but dish out a little constructive criticism regarding the Reverb, which unfortunately produces some pretty harsh metallic artifacts. Of course, if you turn the Distance knob up for longer pre-delay times and dial in a considerable amount of Late Damping, the reverb is actually still very usable.

The Browser page has filters for Instrument Type, Attributes, Musical Style, Author, and Bank, and the Preset page has metadata for Author, Company, Bank Name, and a Comments window. Within both the Browser and Preset Page, eight Easy Parameters and two XY Pads appear near the bottom of the screen, which are basically macro controls with assignable modulation targets…which brings me to the Modulation Matrix in the right sidebar, with eight pages with eight slots each. Yeah, you read that right. That’s sixty-four assignable modulation sources and targets!

The Verdict

SynthMaster is the textbook definition of the “bread and butter” synth. It doesn’t do anything and everything under the sun, but it does plenty. Sure, there’s always room for improvement, but its shortcomings are vastly outweighed by its strengths. I could put together a list of reasons explaining why you should drop everything and purchase SynthMaster immediately, but I think I’ll save myself a bunch of time providing a much shorter list of reasons why not to…

More info: KV331 Audio SynthMaster ($99)