Back in the day the term “synthesizer” usually referred to a monophonic analog synthesizer. In the 1980s digital synths became the norm. There was no more worrying about oscillator tuning drifting, you could store hundreds, later thousands, of sounds without having to figure it all out every time you touched a dial, and they could play many notes at once. In the 1990s people began to long for that quirky, vintage, retro sound of analog instruments. Some true analog synths were created at huge price. And then there was the digital synths that modeled analog. In the 2000s and 2010s analog for the masses, or at least the keyboard playing masses, started to appear. Arturia, known more for their modeling software reproductions of vintage gear, came out with the ground breaking Minibrute. Later they lowered the price bar even more with the Microbrute. I picked one up at Christmas, though I started playing with it in mid-December. So after a month and a half I’ll let you know what I think.
A quick run through the specs of the synth engine makes it sound pretty low end. There is only one oscillator (VCO), one filter, one envelope and one LFO. By comparison, my Moog minimoog Voyager has three VCOs, two envelopes, a noise source, sample and hold, etc. But then, the Voyager costs ten times as much. But there is more to look at like how it sounds and the step sequencer. I was looking at Eurorack sequencers and most standalone step sequencers cost more than the Microbrute. And then there is the semi-modular nature of the synth, something the Voyager has in spades once you add the VX-351, which again costs more than the Microbrute.
That one oscillator on the Micro is pretty amazing. Some synths allow you to choose a wave form. The Voyager gives a continuum from triangle, through saw-tooth and square to pulse. The Micro has eight knobs. The bottom row can give you the basic waves of saw, square, triangle (similar to a sinewave) and a sub-octave, which is a square-wave playing an octave below the fundamental. You can add in each of these waves to make a more complex waveform. So the resulting sound might be some odd combination between a saw-tooth and a square. But then there are the other four knobs. The knob above the square lets you go between a square wave and a pulse wave called pulsewidth modulation, which is pretty standard. On its own this gives sounds that go from clarinet-ish to oboe-ish. Above the saw there is something called an ultra-saw. The ultra-saw adds a second saw peak into the waveform at different distance to the first. This gives the already buzzy saw an even buzzier sound. It also mimics, to some degree a multi-oscillator sound, an effect that is very pronounced if you sweep back and forth with an LFO. Above the triangle wave there is something called a “metalizer” which gives a sound similar to a ring modulator. At high levels this distorts the sound quite a bit. The sub-octave is a square-wave. The dial above it lets you emphasize a harmonic. At the low end you hear the octave below the fundamental. All the way up you here the third harmonic, which is a fifth above the fundamental. With this you can get the two oscillator tuned a fifth apart sound. If you listen to ELP you will recognize that sound. All together this VCO gives you a huge amount of flexibility allowing you to come up with some very complex sounds, even huge sounds, though a lot of fat (or phat) sounds remain beyond its ability.
The very complex, ultra-flexible sound gets fed to a multimode filter. The filter allows for the typical low pass as well as a band pass and high pass mode. Low pass takes out upper harmonics mellowing the sound, band pass takes high and low leaving a band in the midrange and high pass takes out low harmonics leaving a very bright sound with little bass. It is a 2-pole filter. What this means, at least sonically, is you won’t get the buttery smooth Moog sound. Well, you can get some Moog like sounds, but for the most part it comes into its own when you aim for sharper and more metallic sounds. There is filter resonance, which emphasizes the harmonics near the cutoff. This can self-oscillate meaning you can get filter-whistle sounds. And then there is the brute factor. I’ve read that it is some type of feedback loop. To me it is unpredictable. It can go from almost nothing, to heavy distortion to random stuff happening. This adds another dimension to add to a sound, but must be tested on a sound, by sound basis.
The envelope is a standard ADSR type. It is very fast so percussive sounds are a snap. By default you can control the amount the VCA (that’s how loud the sound is) and the filter are affected by the envelope, with the filter also taking negative amounts. The VCA can be switched to plain key-on-key-off mode.
The LFO is pretty standard with three wave-forms – triangle, square and saw-tooth. You can switch the mod-wheel to either control LFO amount or the filter cutoff and you can control the amount of glide between notes.
There is no way to change the pitch bend amount from the front panel. The keyboard is a two octave, mini-key keyboard. It is not velocity sensitive. There is also an octave switch allowing you to detune up one or two octaves and down one or two octaves. This actually controls the keyboard, not the VCO, which becomes important when playing from a full sized keyboard via midi. There is midi in but not out, plus USB.
If that were the end of the story it would be a powerful little synth, but wait, there’s more! There is a little CV (control voltage)patch matrix that allows you to take the envelope or LFO and route them to those four knobs of the VCO (mtalizer, ultra-saw, pulsewidth and suboctave harmonic) plus the filter cutoff and pitch, making two sources and six destinations. There are also CV outs for pitch and gate (when you press a key) plus a gate in to trigger the synth engine. On its own the CV patch matrix adds a lot of flexibility. For instance, you can have the LFO slowly change the ultra-saw. This creates a detuned multi-oscillator sound. Think of the string sound Gary Numan used. Using the envelope with pitch can give you tuned percussion sounds. Here is a quick down and dirty demo. It uses just the Microbrute and is played live on the Micro’s mini-keyboard. I did use a little analog delay while recording, a stomp box that cost more than the micro, and some digital reverb on the mixdown. There are no other outboard effects, no eq and just a quick mixdown.
Remember, there is no memory so each sound was created from scratch as I was recording. Arturia does give you templates, but part of the fun is just those little accidents of not finding the same sound. Those CV ports, though, are tempting. They are compatible with most other CV gear. I used it with my Moog Voyager. Using the VX-351 I could take the Voyager’s envelopes and use them on the Micro making it an instrument with 3 envelopes! Or two LFOs. It goes the other way, too. I used the Micro’s envelope on the Voyager to add a pitch envelope that is independent of the filter or VCA. I used that effect on my recent recording of Green sleeves, which is otherwise all Voyager. You can hear it with that banshee-like bagpipe sound in the middle. The Micro can be used as a complex module for modular synths, such as Eurorack compatible equipment.
And that’s still not all. There is that step sequencer, almost worth the price by itself. You can have a total of eight 64-note sequences. There’s a huge amount that you can do with a step sequencer. If you listen to Flashback Now, which was created with both the Micro and the Voyager, you will hear the sequencer line playing continuously from beginning to end. Bottom line, if you are at all interested in sound synthesis, at less than $300 (I paid less than $250) you can’t go wrong with Arturia’s fabulous Microbrute.
Oh, one more quick demo – this was a practice run for the middle part of the first demo. With the sound isolated you can hear it a little better, though I obviously dialed in the sound a bit different between this and the first demo.
Oh, I just did a quick video of the demo – give it a quick watch:
And a demo of the sequencer and some modular like connections:
Image from Arturia website