USER’S MANUAL Arturia Microbrute User’s Manual 1
PRODUCT AND PROJECT MANAGEMENT Glen T.
TABLE OF CONTENTS 1 Introduction ....................................................................................................................... 5 2 Installation.......................................................................................................................... 9 Usage Precautions..........................................................................................................................9 Register your Instrument ....................................................
The Filter.........................................................................................................................................35 Filter Modes .................................................................................................................................... 35 Cutoff .............................................................................................................................................. 35 Resonance ..................................................
1 Introduction Congratulations, and thank you for your purchase of the ARTURIA MicroBrute analog synthesizer. The MicroBrute is based on the award winning analog designs of its big brother, the MiniBrute. The MiniBrute became a modern classic by bringing excellent sound quality, user features and craftsmanship to the market with a price point that no others were able to match.
Overview of some of ARTURIA’s software, hardware and hybrid instruments After recreating so many legendary analog synthesizers by translating these classic instruments into sophisticated DSP algorithms, the time was right for ARTURIA to introduce an analog synth of its own, the MiniBrute.
2 http://yusynth.net Yves USSON and a couple of wired friends Combining ARTURIA’s acclaimed savoir-faire in designing innovative musical instruments, and Yves’ deep knowledge and experience, both the MiniBrute and MicroBrute analog synthesizers have their roots in the 1970s yet incorporates the best of st the 21 century.
We built the MicroBrute with the idea that many people need an easy to use synth for live and studio purposes. But an easy to use synth must still retain excellent sound quality and enough features to keep a sound designer busy for years. It is true that MicroBrute is simple to use and allows anyone to tweak sounds and make music without having to delve too deep into synthesis but it does not mean that the experienced user will not be impressed with the sound possibilities that this little powerhouse has.
2 Installation Usage Precautions The MicroBrute uses an external power adapter. Do not use any power supply or adapter other than the one provided by Arturia and specified in this manual. ARTURIA accepts no responsibility for damage caused by use of an unauthorized power supply. WARNING Do not place this product in a place or position where one might walk on, trip over, or roll anything over power cords or connecting cables. The use of an extension cord is not recommended.
NOTICE • Use only the provided AC adapter, as specified by ARTURIA. • Read and understand all the instructions. • Always follow the instructions on the instrument. The manufacturer’s warranty does not cover service charges incurred due to a lack of knowledge relating to how a function or feature works (when the unit is operating as designed); reading the manual is the owner's responsibility. Please study this manual carefully and consult your dealer before requesting service.
Register your Instrument Registering your instrument establishes your legal ownership, which entitles you to access the Arturia Technical Support service, and be informed of updates. Additionally, you can subscribe to the ARTURIA newsletter to be informed of ARTURIArelated news as well as promotional offers. Connect to your Arturia account via this URL: http://www.arturia.com/login If you do not have an account, create a new one.
Here is an overview of the MicroBrute synthesizer’s connectors: • Audio Input & Outputs..........6.35 mm (1/4'') mono jacks • Headphone Output…………3.5 mm (1/8'') miniature stereo jack • CV/Gate.................................3.5 mm (1/8'') miniature mono jacks • MIDI Input................................Standard MIDI DIN-5 • USB...........................................Standard USB type B • Power DC Input......................
Warm-Up and General Tuning As with all true analog synthesizers, after being powered-on the MicroBrute needs a warm-up period of approximately five to ten minutes. This allows the oscillator to reach a stable operating temperature, which insures accurate oscillator pitch. Warm-up time depends on the external temperature; a colder ambient temperature will require longer warm-up times, while a hotter ambiance will result in shorter times.
3 Quickstart This chapter provides the basic instruction that you will need to create your very first sounds with the MicroBrute. In subsequent chapters, we’ll get deeper into the sound design process so you can create more animated and complex sounds. Create your first sound: the “basic patch” Once your MicroBrute has been correctly connected to your sound system, set all the controls to the positions shown in Figure 1. This is going to be referenced many times over as the BASIC PATCH.
Introducing The Oscillator The oscillator is the tone-generating center of the MicroBrute. The basic patch has the Sawtooth Wave turned up fully. Try turning the Sawtooth Wave down to 0 and turning up the Square Wave as shown in Figure 2 Figure 2 You will hear the sound go from a brighter, buzzy sound to a more rounded and hollow tone. Now try turning the Square Wave down and turn up the Triangle Wave. The sound will be even darker now.
Introducing The Filter Now that you have been playing with the OSCILLATOR and are familiar with some of the things it can do, return the knobs to the BASIC PATCH settings so that we can explore the FILTER section. The FILTER is just what it implies. It filters, or removes, aspects of the signal that is put into it. The Steiner-Parker filter, originally designed by Nyle Steiner, allows for wide ranging sounds and many sonic possibilities.
Now press a key and try turning the knob clockwise and listen to the result. You will hear the sound get thinner and thinner sounding until it goes away completely at the top of the range. See Figure 5 Figure 5 Band Pass Filtering Now move the MODE switch to BP = Band Pass. If you move the CUTOFF knob you will hear the effects of the Band Pass Filter. This filter allows a range of frequencies both above and below the cutoff point to be passed.
Figure 7 FILTER as an OSCILLATOR? As you may have found out in the last section, turning the RESONANCE control up too high can produce some other pitches. This is called FILTER OSCILLATION. It is when the filter actually becomes an oscillator. With the RESONANCE at the maximum clockwise position, turning the CUTOFF control will vary the pitch that you hear. See Figure 8. Be careful as it can result in some high volume sounds coming out.
Introducing The Envelope The ENVELOPE will allow you to shape the FILTER CUTOFF, the VCA(output volume), and other parameters via the MOD MATRIX. Setup the BASIC PATCH again and we will experiment with the ENVELOPE and the FILTER CUTOFF. Now, change the FILTER and ENVELOPE setting to be the same as you see in Figure 10. Figure 10 The BASIC PATCH has the SUSTAIN value at the maximum setting which basically turns the envelope on full.
ENVELOPE TO VCA The BASIC PATCH has the VCA (Voltage Control Amplifier) set to GATE, which means that the sound will come on when you press a key and will shut off when you release it. To control the LEVEL of audio using the ENVELOPE, move the VCA switch to the ENV position. Figure 11 Figure 11 Since the SUSTAIN slider is at the maximum setting and the ATTACK, DECAY and RELEASE settings are at the minimum settings, you will hear the same thing that you would hear with the VCA set to GATE.
Introducing The LFO Now let’s add some movement to the sound. LFO is short for Low Frequency Oscillator. The LFO is routed to the Pitch of the OSCILLATOR by default. This routing is completed in the MOD MATRIX. The white dotted lines show the default setting. Figure 13 Figure 13 With the BASIC PATCH, the LFO’s output amount is routed through the MOD WHEEL. Play a note and increase the MOD WHEEL and you will hear the pitch start to wobble.
Introducing the Mod Matrix The MOD MATRIX allows you to route the modulation sources (ENVELOPE, LFO, and KEYBOARD CV). You can route the different sources to the destinations with the 1/8” mono jack PATCH CORD’s that come with the MicroBrute. As we said in the LFO section, the LFO defaults to being patched to the PITCH control. Using the BASIC PATCH, insert a PATCH CORD from the jack labeled LFO to the jack labeled FILTER. Now when you increase the MOD WHEEL, the LFO will change the FILTER CUTOFF.
Introducing The Sequencer The SEQUENCER is a fun and musical addition to the MicroBrute. It will allow you to program in phrases and patterns and play them back at different rates. Start off by setting up the BASIC PATCH. Recording A Basic Pattern Set the PLAY MODE switch to RECORD. Figure 15 Figure 15 Now start playing notes on the keyboard. When you start playing notes, it will erase the sequence that is in the currently selected memory. When you are finished, move the PLAY MODE switch back to OFF.
To create a pattern that has rests in it, simply press the TAP/REST button each time you want to place a rest. In Figure 17 you can see the result of the pattern if you were to press the TAP REST button between playing notes. Figure 17 There are a number of settings that can be accessed via the software editor. These features are described in detail in the separate MicroBrute Connection manual.
4 Synthesis Basics Your MicroBrute is a true analog synthesizer, this means that all sounds are produced by analog electronic circuits. No digital computer circuitry is involved in the tone generation, and filtering of the sound. This gives MicroBrute a huge and warm sound. Analog synthesizer architecture The analog sound production chain uses what is called ‘subtractive synthesis’.
Figure 19 The rate at which the oscillator oscillates creates the pitch. The oscillators in a synthesizer are no different than ones found on electrical test equipment, except that they can be put under VOLTAGE CONTROL. A music synthesizer allows you to change the pitch of the oscillator by using a voltage. In the case of MicroBrute, the keyboard, LFO, Envelope or external voltage source can be voltage control sources that affect the pitch.
The Pulse Width Modulator (or PWM) takes the square wave and changes the ratio between the time the waveform is at maximum or minimum. The square wave corresponds to a 50% Pulse Width (PW). The pulse width can be set over a wide range (50% to 90%) making it possible to create a wide variety of tones from hollow and rich to nasal and thin. Figure 21.
Filter What is a filter? In general, a filter follows the oscillator and signal modifiers (wave shapers), and alters the spectral content of the incoming sound. This can involve either removing (filtering out) or emphasizing (resonating) particular overtones. Filters are very important circuits whose design contributes greatly to the synthesizer’s overall sound and character. Filter types on MicroBrute: Low-pass, Band-pass, and High-pass A filter can operate in various ways or modes.
In high-pass mode, partials above the cutoff frequency remain unchanged, while the partials below the cutoff are attenuated. Figure 25 The cutoff frequency in any of these filter types does not have to be static; controlling it with other devices like a keyboard (keyboard tracking), an LFO or envelope generator creates dynamically-changing and interesting timbres.
Voltage Controller Amplifier The VCA or voltage controlled amplifier generally follows the filter. The VCA behaves in a similar way as the volume control, except that it controls the level based on Control Voltage signals. The gain of the VCA is controllable by the GATE or ENVELOPE on the MicroBrute. The amplifier is primarily responsible for shaping a sound’s dynamics.
Low Frequency Oscillator (LFO) An LFO is very much like a regular oscillator except that it typically runs at a much lower frequency. The MicroBrute low frequency oscillator can produce various waveforms at sub-audio frequencies (0.1Hz up to 200Hz). In general the waveform options are sine or triangle, sawtooth, and square, waves. The amount, or output level of the LFO can be controlled before being fed to the target devices to make subtle or wider range sounds.
Finally, the release stage starts upon releasing the key, and sets the amount of time for the level to decrease from the sustain level down to zero. Figure 28 Human Interface To play a tune with your synthesizer, as a player you need a player interface. The MicroBrute provides you with a two-octave, piano-type keyboard.
5 Front Panel Features OSCILLATOR The oscillator and its signal mixer The oscillator delivers three basic waveforms: sawtooth, pulse, triangle wave and our new PLL Overtone oscillator. The bottom row of knobs on the oscillator are the level controls for each waveform. The upper row of knobs are waveshaper controls for each of the waves. The MicroBrute allows you to blend and mix the different waveforms to create more complex sounds.
Triangle and Metalizer The level of the Triangle wave is controlled by the knob labeled with the Triangle symbol. Turning it down completely mutes the signals and moving it up increases the level. Turning the Metalizer knob from fully counterclockwise to fully clockwise warps the triangle wave’s smooth, flute-like sound into complex, metallic-sounding waves.
The Filter Filter Modes This selects among the three filter modes: LP (low-pass), BP (band-pass), and HP (high-pass). The LP mode is the most commonly-used, and provides sounds which are full/fat and round. The BP and HP modes provide thinner and harsher sounds. Cutoff This knob adjusts the filter’s cutoff frequency. The frequency range goes from below 20Hz when turned fully counter-clockwise up to 18kHz when fully clockwise. For example, in LP mode you can adjust a sound’s brightness.
Brute Factor The Brute Factor feature drastically alters the filter characteristics so expect highly unpredictable results at extreme settings. You have been warned! The Brute Factor is a special MicroBrute feature inspired by a common patch used on a famous vintage mono-synthesizer that connected the headphone output to the external audio input. The result is a kind of feedback loop that’s ideal for raspy and grungy sounds.
KBD Tracking The filter cutoff frequency can also be keyboard-controlled. The KBD Tracking knob lets you adjust how the cutoff follows the keyboard. At the full Counter-clockwise position the keyboard CV will not affect the filter cut at all. With lower filter settings you will hear the sound get darker and darker as you play up the keyboard. To have the sound track with the notes you are playing and have the filter cutoff remain even across the scale, set the knob in about the 12 o’clock position.
sound. With the switch set to Env, you will then be able to control the level using the controls from the envelope. The type of sound that you are trying to get will determine the settings you choose. Attack slider – the Attack slider sets the duration of the envelope’s first stage. The Attack time ranges from 2.5ms seconds to 2.5 seconds. Decay slider – the Decay slider sets the duration of the envelope’s second stage. The Decay time ranges from 2.5ms to 2.5secs.
Wave Select The LFO offers several modulation waveforms that can be selected using the switch. The options are; square, sawtooth, and triangle waves. Amount The Amount knob regulates how wide the modulation coming from the LFO is. It allows you to attenuate the level of the signal to get more subtle effects. Rate The rate knob allows you to set the speed of the LFO. It allows for a range of .1Hz – 200Hz.
Mod Wheel The Mod Wheel can be assigned to two different functions. The Mod Wheel switch, in the controls section, determines the Modulation wheel assignment. Mod to Cutoff The Mod Wheel is routed to the Cutoff frequency control. This, in effect, is the same as the Cutoff Knob but in a more user-friendly performance setup. Being that this works in conjunction with the Filter Cutoff control, there are some settings of the Cutoff that will end up with you not hearing any effect of moving the Mod Wheel.
Mod Matrix The Mod Matrix allows for patching modulation sources to modulation destinations. The Jacks are standard 1/8” (3.5mm) mono jacks and all connections hold to the standard 1V per octave standard that most modern modular synthesizers support. When you patch a jack into one of the CV Outs, it will break the normal connection. The Matrix’s standard connections are ENV > Metal & LFO > Pitch.
• Pitch – this controls the Pitch of the oscillator. By default, the LFO Output is patched to this to allow for LFO vibrato. • Filter – This allows control over the Filter Cutoff control. Note that the filter section already allows for both Envelope and Keyboard controls apart from the Mod Matrix. • PWM – This is the input for the Pulse Width control. General Controls Keyboard The MicroBrute keyboard covers a two-octave range, which can be extended using the Octave Down/Up buttons.
The Octave section transposes the MicroBrute keyboard over a wide pitch range. One LED among the five colored LEDs (-2 red,-1 orange, 0 green ,+1 orange,+2 red) is lit at a time and indicates the transposition octave. The default selection is 0 (green LED), where the leftmost C key corresponds to C2 (130.81Hz) and the rightmost C key corresponds to C4 (523.25Hz). To shift the keyboard up by one octave press the Up button.
Pattern This knob selects between the 8 patterns. Play Mode This selects between PLAY, OFF and RECORD. • Play - In Play mode, the sequencer will play based on the Keymode. Keymode is set in the MicroBrute editor software. • Off – This turns the Sequencer Off. • Record – This puts the sequencer into Record mode. This will allow you to record over an existing sequence.
Tap / Rest The Tap /Rest button has two functions: 1. Tap Tempo 2. Inputting Rests when recording sequences. Tap Tempo – the Tap Tempo button will allow the user to manually set the rate of the sequencer by tapping the button in real time. The number of taps that get averaged to calculate the tempo can be set using the MicroBrute Editor software. Rest – The Tap Tempo button will act as a rest input when you are recording a sequence.
6 Rear panel Power supply The Power button turns the power on/off. The DC connector receives the MicroBrute’s external power supply plug. Only connect the 12V DC, 1A, center positive power supply that came with your MicroBrute. Connecting any other power supply could damage the MicroBrute. USB The USB port allows interfacing with a personal computer.
Audio In The Input Level potentiometer adjusts the amount of an external audio source (guitar, synth, drum machine, etc.) that can be plugged into the MicroBrute signal chain via the rear panel Audio Input jack. This makes it possible to process an external audio signal with the filter and amplifier; also note that this signal can trigger the envelopes. NOTE: this is a line level input. To use this with a guitar or microphone you will need to boost the levels with a pre-amp first.
The MicroBrute can also control other analog devices. The Pitch Out 1/8” jack provides the CV produced by the MicroBrute keyboard as well as by the Pitch wheel. The keyboard’s GATE signal is also available on the Gate Out 1/4” jack. The Gate is a standard positive going 0-5V gate. The CV inputs and outputs are standard 1V per octave. Get MicroBrute Connection The “MicroBrute Connection” software and its dedicated User's Manual are freely downloadable from the ARTURIA website: www.arturia.
7 Legal Notes No liability for consequential damages Neither ARTURIA nor anyone else involved in the creation, production, or delivery of this product shall be liable for any direct, indirect, consequential, or incidental damages arising out of the use of, or inability to use this product (including without limitation, damages for loss of business profits, business interruption, loss of business information and the like) even if ARTURIA was previously advised of the possibility of such damages.
• If these corrective measures do not bring any satisfied results, please contact the local retailer authorized to distribute this type of product. If you cannot locate the appropriate retailer, please contact ARTURIA. The above statements apply ONLY to those products distributed in the USA. Canada NOTICE: This class B digital apparatus meets all the requirements of the Canadian Interference-Causing Equipment Regulation.
