This article includes:

• Quick Start
• Feature Overview
• Interface Overview
• Voice Architecture Overview
• Header Section Controls
• Voice Settings
• Sound Source Module Controls (Oscillators, Noise)
• Mixer Module Controls
• Filter and Insert FX Module Controls
• LFO / S+H Module Controls
• Envelope Controls (Filter, Aux, Amp)
• Output/FX Module Controls
• Modulation Matrix Controls
• Multi-Seg Controls
• Output Effects Controls
• MIDI Continuous Control and Automation

Our infinite, larger-than-life synth that always sounds like a record.  

Exclusively for UAD Spark, Opal is our epic-sounding flagship synth that's perfect for producers, sound designers, and musicians. This analog-meets-wavetable synth gives you huge-sounding morphing filters and powerful UA effects — yet always keeps you close to album-ready sounds, no matter how deep you explore. 

• Get giant, inspiring sounds from the world's best-sounding analog-meets-wavetable super synth 
• Use morphing filters, oscillators, LFOs, and noise to unlock new creative paths
• Add studio-quality UA effects like vintage spring reverb, tape delay, modulation, and authentic 1176 compression
• Go deep into synthesis without getting lost, thanks to impeccably crafted presets 

Fire Up a Super Synth

Opal's unique analog-meets-wavetable synth engine lets you create epic sounds and craft songs within minutes. With morphing filters, oscillators, LFOs, and noise, Opal is a modern soundscape maker with deep analog roots. 

Create with World-Class UA Effects

With onboard studio-quality UA effects like ambience and vintage spring reverbs, tape delay, modulation, and authentic 1176 audio compression, Opal makes any production fuller, and more professional sounding.

Find Inspiration Fast with Album-Ready Presets 

Get just the right sound using Opal's gorgeous presets, lovingly crafted by the synth geeks deep within the halls of UA. Curated for fast use across genres, Opal's presets ensure you'll capture inspiration the moment it strikes. 

Key Features:

• Breakthrough analog-meets-wavetable synth with continuously morphing oscillators, noise, filters, and LFOs
• Studio-quality UA effects, including premium studio reverbs, tape delay, modulation, 1176-style compression, and more 
• Hundreds of curated presets across multiple genres, for instant professional sound 
• Hardware-inspired controls and layout for easy navigation and sound sculpting

 

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Quick Start

Opal's controls in the main panel section have a familiar workflow and layout that is similar to much simpler analog hardware. For those who like to dive deeper, the views in the display section offer intuitive visual feedback and easy navigation through the more complex features.

Before diving into the details, let's take Opal for a quick test drive. First, load the instrument in your DAW and input-enable the track (see the DAW's documentation for these instructions), then play with some features in the steps below.

 

1. Explore Opal's presets. In LUNA, click the Presets button at the top of the instrument, where you can select presets with LUNA's contextual browser. In other DAWs, a browser pane appears to the left of Opal. Click any of the available presets while playing your MIDI controller. You'll hear the sound of each preset as you step through the names. 
2. Play with the Macro knobs. When you have found a preset that you like, try adjusting Opal's four white macro knobs at the top right of Opal's window. The macros are meta controls that adjust multiple parameters simultaneously, and each preset can have different macros assignments. The preset sound designers have carefully crafted expressive macros, so be sure to explore them.
   
   Tip: Holding the shift key while dragging knobs or sliders gives you extra precision for fine-tuning a setting. Option-clicking knobs or sliders returns the control to its default position.
   
   
3. Play with controls in the Panel Section. For example, you can adjust the preset's Filter Cutoff or Resonance, or change the "mode" (shape) of the filter by rotating the Filter Mode Dial.
   Tip: The notches in the silver rings surrounding the round oscillator and filter scope displays indicate that these dials are adjustable controls.
4. Navigate to additional synth controls by clicking the circular buttons found at the top right of most modules. The Display Section above the Panel will show all the controls relating to the currently selected module (the currently selected module's button is lit). 

This barely scratches the surface of what Opal can do, but we hope it gives you an idea of the capabilities of this amazing instrument! Read on to learn about all the different parts of this synthesizer and how they work together.

 

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Feature Overview

Opal is a state of the art synthesizer that retains the sound, simplicity, and joyful experience of using classic hardware synthesizers. Universal Audio's renowned DSP scientists carefully modeled the oscillators, filters, envelopes, and other sonic characteristics, while the product and user interface teams ensured that everything is presented in a way that is clear, intuitive, and fun. 

User Interface

The most important knobs and sliders are always visible in the Panel section. If you have used classic hardware synthesizers, Opal will immediately feel familiar to you. The Panel section has just the right amount of complexity to give you deep sound design possibilities without feeling overwhelming or daunting. The signal path controls are laid out in a right to left configuration with clear labeling.

After selecting a module in the Panel section by clicking its navigation button or header, graphics and additional controls related to the module are shown in the Display section. This control arrangement results in almost no "menu diving" when using Opal, allowing a faster and more intuitive music making experience. All of this has been done in the interest of minimizing "cognitive load" while playing the instrument. By spending less time thinking about the location and status of controls, you can dedicate more of your mental bandwidth to making music.

Understanding the Opal user interface is an important part of unlocking its full potential, so we have covered this topic in greater detail in the Interface Overview section.

Analog/Wavetable Morphing Oscillators

Opal has three morphing  oscillators that can function as analog or wavetable sound sources. Opal's oscillators provide an extraordinarily rich and analog-like sound that is free of aliasing. The wavetable oscillators are crafted to provide maximum sonic versatility, and the analog oscillators feature the ability to smoothly morph between the standard analog waveforms (sine, triangle, saw, and pulse). Having access to all the "in between" waveshapes and being able to modulate the morphing control itself opens up exciting sound design possibilities. 

Morphing Filters

Continuing with the theme of morphing, Opal has two multimode filters that can smoothly change between lowpass, bandpass, highpass and notch modes. Furthermore, the filter slope can also be smoothly adjusted and does not have hard set points, so you're not limited to 1, 2, 3, or 4 pole filters (6, 12, 18, or 24 dB/Octave, respectively). You can, for example, set a filter to have 2.2 poles if you wish. The ability to access and modulate "in between" filter modes and slopes facilitates interesting sound design possibilities.

Morphing LFOs

Instead of a simple waveform switch, Opal's LFOs have continuous modulatable control over shape, tilt, and randomness.

Analog modeled envelopes

The Filter, Aux and Amp Envelopes of Opal go beyond the typical interpolated envelopes. With Opal's envelopes, the complete analog circuit behavior and sonic punch of classic hardware ADSR modules is closely modeled.

Multi-Seg

Multi-Seg (multi-segment function generator) can be used as a complex LFO, Envelope, Step-sequencer, or anything in-between. Opal has two extremely flexible Multi-Segs that can help you create exciting new sounds.

Multi-Segs have up to 32 separate segments (stages) and you can set the rate, level, shape, and gate length of every stage individually. This lets you create beautifully complex modulations that go well beyond what you can do with basic LFOs and ADSRs. Multi-Segs can be triggered in many ways, and the output appears in Opal's Modulation Matrix just like any other modulation source. 

When looping is engaged, a Multi-Seg behaves like an LFO except that it has a complex waveshape. When looping is off, a Multi-Seg behaves like an ADSR with up to 32 separate stages. In both cases, each segment can trigger or re-trigger envelopes and other parts of the synthesizer for more dynamic sounds. Multi-Segs can even be set to function like a step sequencer if desired. There are vast creative opportunities in just this part of the synthesizer, which is covered in detail in the Multi-Seg section.

Flexible Modulation Matrix

Opal has a very powerful Modulation Matrix, letting you connect any control source (such as the velocity of a played note or the output of an LFO) to any of the available destinations (such as filter cutoff frequency or oscillator pitch). The flexible Modulation Matrix allows much more freedom to connect the different parts of the synthesizer together to create the sounds you want. Complete details are in the Modulation Matrix section.

 

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Interface Overview

The Opal interface has been laid out to maximize clarity and ease-of-use. The interface contains the Panel Section, Display Section, and Header Section. All controls within these main areas are detailed later in this guide.

Panel Section

Opal's most important controls (for example, Oscillator pitch, mixer levels, and filter cutoff frequency) are in the Panel Section. Nearly all of the controls in this section have fixed locations and remain visible at all times, letting you immediately jump to important controls without menu diving or having to remember where you are in the synth.

Display Section

The Display Section shows detailed information about, and controls for, a specific module that is highlighted in the Panel Section. For example, if the Filter and FX module is selected in the Panel Section, the Display Section will show controls relating to Opal's filters and insert effects such as each filter's type, slope, routing, and so on.

Tip: To change what is shown in the Display Section, click the circular selector buttons or the header at the top of another module (Oscillators, Filters and Insert FX, LFO, Multi-Seg or Output / FX).

Header Section

The Header Section is found at the top of the instrument. It contains the Modulation Wheel and Macro control knobs, and quick access to the Modulation Matrix and global Voice Settings.

 

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Voice Architecture Overview

Opal uses a familiar classic synthesizer layout. The underlying signal path is based on a tried-and-true arrangement that is powerful and easy to understand.

The Panel Section contains individual synthesis modules with controls that adjust their functions. The signal path through these modules is illustrated below.

Each module handles a specific part of the synthesis process and the individual controls are covered in detail later in this guide. Signals generally flow from left-to-right across the Panel Section. By that, we mean that raw sounds are generated by the Oscillator modules and blended together in the Mixer module before being passed on to the Filters and Insert FX modules and finally sent on to the Output module.

The LFO, Multi-Seg and Envelope modules generate control signals. These signals are not directly audible because they are not in the signal path of the synth. Instead, you use these control signals to modulate (i.e., create motion with automation) many parameters throughout the synth. For example, you may want to modulate an oscillator's pitch with an LFO to create a vibrato or to connect an ADSR envelope to a filter's cutoff frequency to create a slow sweep or fast "snap" sound. You can even use one modulator to modulate a second modulator for wilder and more unpredictable effects! These types of connections can be made through Opal's Modulation Matrix.

 

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Header Section Controls

The Header Section controls give you instant access to some important performance parameters.

Modulation Wheel

The Modulation wheel on your MIDI controller transmits messages on MIDI CC#1 (Modulation). This control is a convenient way of setting the modulation amount of a preset, even if you do not have a MIDI controller connected to your computer. If you do have a MIDI controller connected and turn its mod wheel, you will see that this on-screen knob mirrors the setting.

You can rename the Modulation wheel by clicking its label. The position of the control is saved with each preset.

Macro 1-4 Knobs

Each macro knob controls a parameter, or multitude of parameters, within an easy to use, musical range. Each Macro has a custom label that can be renamed so the macro's function is easy to understand.

The four Macro knobs provide quick access to the most important sound-sculpting controls. You can define your own macros in Opal's Modulation Matrix, and the position of these controls are saved with each preset.

Matrix Button

This button shows Opal's Modulation Matrix in the Display Section. The Modulation Matrix lets you connect various control sources (such as MIDI note velocity or Opal's LFOs and Envelopes) to dozens of different destinations (such as filter cutoff or oscillator pitch) letting you build up your sounds the way that you want.

This area is covered in detail in the Modulation Matrix section of this guide.

Voice Settings Button

This button shows Opal's Voice Settings in the Display section, where you can set various global parameters such as polyphony count, vibrato and pitch bend ranges, and more.

 

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Voice Settings

These settings control parameters that apply to all areas of Opal, such as global tuning, polyphony count, and more. To access Voice Settings, click the VOICE button in the Header section.

Voices

This drop menu sets the polyphony count of the synthesizer. The MONO setting turns Opal into a monophonic instrument while the remaining settings provide 4, 6, 8, or 12 voices of polyphony.

Tip: Reducing the number of voices reduces the computer's CPU load, which may result in smoother playback on older computers with slower processors.

Note Trig

This drop menu sets the Amp Envelope's triggering behavior when the VOICES parameter is set to MONO. 

Note: If VOICES is set to any other than MONO, this menu is deactivated and "--" is displayed.

• ALWAYS - In this mode, the Amp envelope is always retriggered when a note is played. 
• LEGATO - In this mode, the Amp envelope is triggered on the first note of a legato passage and continues through its cycle as long as any note is being held. The subsequent notes in the legato passage do not retrigger the Amp envelope. Once all notes are released, the envelope resets and can be triggered from the beginning.

Priority

This drop menu sets legato key prioritization when the VOICES parameter is set to MONO. This can be useful if you want to emulate the keyboard behavior of certain classic synthesizers.

Note: This parameter is only available when VOICES is set to MONO. If VOICES is set to any other setting, this menu is deactivated and "--" is displayed.

• LOW - When playing legato passages, only notes below the currently held note will play. If the newly played note is above the currently held note, it will not play.
• HIGH - When playing legato passages, only notes above the currently held note will play. If the newly played note is below the currently held note, it will not play.
• LAST - The latest note played in a legato passage always has priority and will play regardless of whether that note is above or below the currently held note.

Vibrato Range

This drop menu sets the range of pitch vibrato created when you turn up your MIDI controller's modulation wheel (or Opal's Modulation wheel). By default, the vibrato speed is set by the rate of LFO 1.

The Vibrato Range is set in semitones. Selecting lower numbers results in a "tighter" vibrato, whereas selecting higher numbers will result in a wider maximum vibrato with larger swings in pitch.

Tip: To make the modulation wheel control something other than vibrato depth, set the Modulation Wheel Range to 0, and use the Modulation Matrix to create your desired routing.

Bend Range

This drop menu sets the range of the pitch bend wheel in semitones. For example, setting this to 12 will let you bend the pitch of a played note up or down by one octave.

Glide Rate

This knob sets the rate of note portamento, which lets the pitch change in a smooth, continuous manner as you play notes. Low settings will transition quickly whereas high settings will transition more slowly. The nearby MODE parameter determines the exact gliding behavior.

Glide Mode

Opal's Glide functionality can operate in two modes:

Note: This parameter is only available when VOICES is set to MONO. If VOICES is set to any other setting, Glide is locked in TIME mode and this menu is deactivated ("--" is displayed).

• PITCH - In this mode, the rate of the glide remains consistent, resulting in a longer glide for larger note intervals. In other words, a one octave glide takes 12 times longer to complete than a one semitone glide. This is the way most classic analog synthesizers behave.
• TIME - In this mode, the overall glide time is fixed regardless of the note interval being played. This means the glide always takes the same amount of time regardless of whether you play notes that are one semitone or one octave apart.

Glide Trig

Opal's Glide functionality can be triggered in two ways:

• ALWAYS - In this mode, glide always occurs. In other words, if no notes are currently held down and a new note is played, there will still be a glide from the last played note to the new note. 
• LEGATO - In this mode, glide occurs only during legato (when a new note is played while another is still held down). If no notes are held down, playing a new note results in the new note being played on-pitch without any preceding glide. 

Tuning

This knob sets the global tuning of Opal. The default 0 setting provides a standard A440 tuning (the A above middle-C is set to 440 Hz). Rotating this knob lets you adjust Opal's overall tuning ±100 cents. Option-click the knob to reset its value to 0.

 

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Sound Source Module Controls (Oscillators, Noise)

Opal has four sound sources: Oscillators 1, 2, 3 and a noise generator. Each oscillator can be set as either analog modeling or wavetable sound generators.

Waveshape

The ring around the Oscilloscope display is a morph dial that adjusts the wave's shape:

• When the oscillator is set to operate in Analog mode, turning the dial smoothly morphs the waveform between sine, triangle, sawtooth, and square waves with varying duty cycle ("PWM") amounts.
• When the oscillator is set to Wavetable mode, turning this dial smoothly morphs through the various wave shapes (or "slices") contained within the loaded wavetable.

Tip: With Opal's morphing oscillators, you can create many interesting sonic textures by modulating an oscillator's WAVE parameter in the Modulation Matrix. For example, you can create the classic "PWM'ed" square wave sounds by modulating an analog oscillator's WAVE parameter through the pulse area of its range.

Coarse

This knob adjusts the coarse tuning of the oscillator pitch ±48 discrete semitones.

Fine

This knob adjusts the fine tuning of the oscillator. The available range is ±100 cents. 

Ensemble

This knob adjusts the Ensemble voice stacking effect built into the Opal oscillators. This turns one oscillator into three detunable voices operating in unison.

• When the knob is at its minimum position (counter-clockwise), Ensemble mode is off and only the single oscillator is heard.
• Rotating the knob clockwise from the minimum position switches on the Ensemble effect and provides an increasing amount of detuned "thickness" to the oscillator. The maximum spacing is 50 cents (a quarter-tone between each voice).

FM (Osc. 1 Only)

Opal's first oscillator can have its frequency modulated by the output of the second oscillator. This technique is known as frequency modulation and the FM knob sets the amount or "strength" of modulation that takes place. A low setting means there is no frequency modulation, while increasing it means that the second oscillator will have an increasingly pronounced impact on the timbre of the first oscillator.

Tip: The Display Section includes a horizontal FM slider that mirrors the FM knob on the Panel Section. These two controls are linked and you can use whichever is more convenient.

Sync (Osc. 2 Only)

Opal's second oscillator includes a SYNC knob that creates the popular "oscillator sync" sound found on many classic analog synthesizers. The effect happens when attempting to synchronize two oscillators that are out of pitch from each other. When the sync source oscillator is higher pitched than the synchronized oscillator, the synchronized oscillator restarts itself during its wave cycle resulting in the wave being "chopped up". This creates distinctive and distorted harmonics related to the pitch of the oscillator that is providing the synchronization.

Opal's oscillator sync feature works as follows:

• When the knob is set to its minimum position (counter-clockwise), Sync is disabled.
• Rotating the knob clockwise from the minimum position enables Sync. The oscillator now generates a second (silent) pitch that is used as a sync source.
• Increasing the sync knob raises the frequency of the (silent) sync source up to 36 semitones. This causes the audible waveform to be retriggered or "chopped up" more and more frequently as you turn up the knob. The result is interesting new harmonic textures that appear as you sweep the knob.

Tip: To replicate the retro "sync'd oscillator" sound from the 1970s, use an envelope to modulate the sync amount in Opal's modulation matrix.

About oscillator sync

Opal's sync feature is implemented in a unique way and has two advantages over more common syncing methods. First, it works in both analog modeling and wavetable oscillator modes. Second, there is no need to use a second oscillator as a sync source since the oscillator generates its own internal sync source.

AM Slider (Osc. 2 only)

Opal's second oscillator has a horizontal AM (Amplitude Modulation) slider that provides an effect similar to ring-modulation. This lets the waveform of the third oscillator modulate the amplitude (loudness) of the second oscillator. The slider sets the strength of this modulation.

Sub (Osc. 3 Only)

Opal's third oscillator has a sub-oscillator that can output a square wave that is either one or two octaves below the main output. The SUB knob sets the sub-oscillator output level, while the nearby "1" and "2" buttons determine its octave range (one or two octaves below the main pitch).

Analog / Wavetable Selector

The Analog/Wavetable switch sets the operating mode of each oscillator. The current mode is highlighted. 

• When set to ANALOG, the oscillator becomes a modeled analog sound source and the Oscillator Morph Dial morphs through the classic analog shapes. Clicking one of the wave shapes to the right of the switch will snap the oscillator to that waveshape.
• When set to WAVETABLE, the oscillator becomes a wavetable sound source and the Oscillator Morph Dial morphs through the available wave shapes in the currently loaded wave table. The name of the loaded wavetable is displayed to the right of the switch and clicking it will open Opal's wavetable browser.
• The vertical slider at the right side of the display lets you smoothly morph your analog or wavetable waveshape.

Keyboard Tracking Switch

Each oscillator has a small keyboard icon in the Display Section. This icon switches keyboard tracking on and off for its associated oscillator. When this icon is lit, keyboard tracking is engaged and the oscillator's pitch will follow the note played on your MIDI keyboard. If the icon is unlit, pitch tracking is disengaged and the oscillator's pitch remains constant regardless of what note is played.

Note: The Keyboard Tracking Switch is an on/off switch that sets tracking to 100% (on) or 0% (off). If you would like to set a different amount of pitch tracking (for example 50%), you can do this through the Modulation Matrix by connecting the "Note Pitch" source to your desired destination and adjusting the AMOUNT and OFFSET sliders.

Noise Color

Opal's Noise generator is capable of morphing between several different flavors of noise: Red, Red-Pink, Pink, Pink-White, and White. Moving the vertical slider on the right morphs between the different available options.

 

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Mixer Module Controls

Opal's Mixer lets you set the level of each sound source (Osc. 1-3 and Noise) and choose where each source is routed after it leaves the mixer.

Level Knobs

These knobs set the level of the corresponding sound source.

Filter Routing Buttons

These buttons let you select the output destination of each sound source. The LEDs beneath the buttons indicate the currently selected destination(s).

• FILTER 1 sends its associated sound source to Opal's first filter and the INSERT FX. Note that if Filter Routing is set to SERIES, then the output of this filter is sent through Filter 2 as well. 
• FILTER 2 sends its associated sound source to Opal's second filter.
• FILTER 1+2 sends its associated sound source to the first and second filters.
• THRU skips the filter module entirely and sends its associated sound source directly to the Output module.

Tip: The filter routing display (shown in the Display panel when the Filter and Insert FX module is selected) provides a visual reference of how the filter routing is set. Clicking the Filter Routing buttons in the Panel section will update the graphic. Conversely, clicking the 1, 2, 3, and N labels in the graphic will update the routing LED indicators in the Panel section.

 

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Filter and Insert FX Module Controls

Opal has two morphing multi-mode filters and an Insert FX module with several available effects. These morphing filters and effects are used to add and sculpt harmonic content. The filters share a common envelope and the filter/insert effects can be arranged in series or in parallel.

Filter Mode

Opal's filters have a 360º wrapping morph that goes continuously from lowpass, to bandpass, to highpass, to notch, and back to lowpass. There are no stops at the ends when adjusting or modulating the filter mode, allowing for some interesting sound design possibilities. To adjust the filter mode, drag the dial ring surrounding the round visualization of the filter shape.

Tip: The minimum and maximum mode settings of the filter result in lowpass filtering. This opens up interesting modulation possibilities with certain LFO shapes (triangle, for example) because you can smoothly cycle through all of the filter modes with no steps or discontinuities.

Cutoff

This knob sets the cutoff frequency (brightness) of its associated filter.

Filter Resonance (RES)

This knob sets the resonance amount of its associated filter.

Slope

This morphing dial determines how sharply a filter attenuates signals beyond the cutoff frequency. This is sometimes called the "steepness" of a filter. You can smoothly morph the filter from a traditional four pole (24 dB/octave) slope down to a single pole (6 dB/octave) design.

Envelope Amount (ENV AMT)

This knob adjusts the amount by which the Filter Envelope modulates the Filter Cutoff frequency. This is a bipolar knob ranging from ±100% meaning that:

• Setting the knob to the center position ("12:00 o'clock") will result in the Filter Envelope having no effect on the filter cutoff. This is because the modulation amount is 0%.
• Turning the knob clockwise will result in positive modulation. This means that the envelope will increase the current cutoff frequency when the envelope is triggered.
• Turning the knob counterclockwise will result in negative modulation. This means that the envelope will decrease the current cutoff frequency when the envelope is triggered. 

Keyboard Control (KB AMT)

Keyboard Control (or "key tracking") is a feature that lets you automatically raise or lower a filter's Cutoff Frequency as higher or lower notes are played on the keyboard. This mimics the sound of many acoustic instruments since higher notes naturally tend to have a "brighter" timbre.

This knob ranges from 0-100% and adjusts the strength of the key tracking. At 0%, Keyboard Control has no effect and the filter cutoff is not affected by the notes you play. At 100%, the filter tracks the notes you play chromatically (a self-oscillating filter's resonant "whistle" is perfectly in tune as you play up the keyboard).

Tip: If you want scalable or inverted key tracking (higher notes result in lower filter cutoff), or you would like values greater than 100%, use the Modulation Matrix.

Filter Envelope

Note: For more detailed information about these filter controls, refer to the Envelope Controls section.

The Filter Envelope is used to develop and add simple motion to the frequency content of the sound. The ADSR (attack, decay, sustain, release) sliders control the cutoff frequency of Opal's filters. 

Tip: If you want to create filter modulation that's more complex than ADSR (for example, adjustable curves and multiple break-points), use one of Opal's MULTI-SEGs.

For example, a fast attack on a low-pass filter with medium frequency and resonance results in a punchy, bright sound on the initial note trigger. A longer attack time on the same filter "swells" the sound from dark to bright over a longer period of time, creating a slower blooming sound. 

The Decay slider does the same thing for the frequency content in reverse. It adjusts how quickly the filter frequency is reduced after the attack stage ends. Sustain sets the level at which the filter envelope is held while a note is held (at the end of the Decay stage). Finally, the Release slider sets the amount of time the envelope takes to return to zero once a note is released.

Filter Envelope Velocity

Clicking an envelope's header reveals two additional controls: VELOCITY and GATE SOURCE. To return to the sliders, click the header again.

Velocity (VEL)

This horizontal slider in the Display Section (visible when the Filter module's Display Panel Selector button is lit) adjusts how note velocity modulates the Filter Cutoff frequency. This is a bipolar knob ranging from ±100% meaning that:

• Setting the knob to the center position ("12:00 o'clock noon") will result in keyboard velocity having no effect on the filter cutoff. This is because the modulation amount is 0%.
• Turning the knob clockwise will result in positive modulation. This means that more forceful key strikes will increase the current filter cutoff frequency.
• Turning the knob counterclockwise will result in negative modulation. This means that more forceful key strikes will decrease the current filter cutoff frequency.

FM-LFO 2

This horizontal slider in the Display Section lets you use Opal's second LFO to modulate the Filter Cutoff frequency.  This is a bipolar knob ranging from ±100% meaning that:

• Setting the knob to the center position ("12:00 o'clock") will result in no LFO modulation of the filter cutoff. This is because the modulation amount is 0%.
• Turning the knob clockwise will result in positive modulation. This means that a rising LFO will increase the current filter cutoff frequency.
• Turning the knob counterclockwise will result in negative modulation. This means that a rising LFO will decrease the current filter cutoff frequency.

Insert Effect Selector (INSERT FX)

This drop menu in the Display Section selects the insert effect that is loaded into the Opal signal path. The effects are described in detail later in this section.

Effect Knobs 1-3

These knobs adjust three parameters of the insert effect that is currently loaded. The labeling and function of these knobs depends on what effect is loaded. The individual insert FX controls are described later in this guide.

Routing

This drop menu in the Display Section determines the routing of the signal path through the two filters and insert effect.

Tip: The Filter Routing buttons in the Panel Section (Mixer Module) or the routing diagram (Filter Module) determine how Opal's sound sources are routed through the filters. You can see how the sound sources (labeled "1", "2", and "3" for Oscillators 1-3 and "N" for noise) are routed in the display. The display makes it easy to visualize your signal flow and clicking a number or letter in the display will immediately route that source to your selected destination. For more information, refer to the Mixer module.

Series

When SERIES is selected, the output of Filter 1 is routed through the Insert FX module to the input of Filter 2.

Parallel

When PARALLEL is selected, the output of Filter 1 is routed through the Insert FX module before being sent to the Output Section. The output of Filter 2 is routed to the Output Section without going to the Insert FX module.

Insert Effects

Insert effects are placed in Opal's signal path directly after the first filter and are used to add distortion, harmonics, "physical modeling" style timbres (via the Comb +/- inserts) or other tonal richness to each voice. 

You can select the effect with the INSERT FX drop menu in the Filter module. After an effect is selected, you can adjust that effect's parameters using Effect Knobs 1-3 below the drop menu.

Note: Insert effects are applied per voice and each voice of polyphony (every note in a chord, for example) has its own separate instance of the selected effect. These effects do not blend together or affect each other.

Distortion

A hard clipping distortion effect with aggressive flattening of the waveform peaks.

• Drive - Adjusts the input gain of the effect and determines how much of the incoming signal will exceed the clipping threshold.
• Offset - Introduces a DC offset to the incoming signal to create asymmetric distortion. When set to the center position, there is no DC offset. Rotating the knob right of center introduces a positive offset while rotating to the left of center introduces a negative offset.
• Output - Adjusts the output level of the effect. Use this to attenuate an overly loud output or to provide make up gain if the output has been reduced by the insert effect.

Overdrive

A more gentle type of distortion, comparable to overdriving a guitar amp. Signals exceeding the threshold are rounded off more gradually resulting in a distortion that is less "bright" and contains less high frequency sizzle.

The DRIVE, OFFSET, and OUTPUT controls are the same as those found on the DISTORTION insert effect.

Fold

Wavefolding is a type of distortion in which a waveform that exceeds a loudness threshold is inverted and folded back on itself. This results in a specific type of distortion with a characteristic sound.

The DRIVE, OFFSET, and OUTPUT controls are the same as those found on the DISTORTION insert effect.

Sign

This "comparator" insert effect creates square waves out of incoming signals by comparing the loudness of incoming signals against an internal reference. If the incoming signal exceeds the reference, the circuit outputs the maximum signal. If the incoming signal level is below the reference, the circuit outputs silence. Note that the circuit has a "soft knee" letting you gradually ease into the effect as the incoming level increases, providing sound shaping flexibility.

• Drive - Adjusts the input gain of the effect and determines how much of the incoming signal will exceed the comparator's internal reference.
• Offset - Sets the duty-cycle of the outgoing square wave. This is similar to the "PWM" control found on the square wave output of analog synthesizers.
• Output - Adjusts the output level of the effect. Use this to attenuate an overly loud output or to provide make up gain if the output has been reduced by the insert effect.

Comb+, Comb-

Comb filtering is an effect in which a signal is duplicated and the duplicated copy is delayed by a very small time interval before being added or subtracted back to the original sound. Doing so creates a "phasey" type of filter containing lots of regularly spaced notches resembling a comb.

The "Comb+" selection adds the duplicated copy to the original whereas the "Comb-" selection subtracts the duplicated copy from the original. While the general concept is the same between the + and - versions of the insert, note that they do provide quite different tonal variations to the sound.

• Pitch - Sets the "pitch" of the filter by adjusting the small delay amount applied to the duplicated copy of the sound. The available range is ± 24 semitones.
• Feedback - This comb filter includes a "regeneration" loop that lets  you feed some of the output back into the input for increased repeats and tonal variation. This knob adjusts the amount of feedback from 0-100%
• Damping - This knob lets you attenuate some of the high frequencies and bring the brightness of the effect under control.

 

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LFO / S+H Module Controls

Opal has two flexible LFOs and a Sample and Hold (S+H) in this module.

Tip: To create complex multi-stage waveshapes that go beyond the standard LFOs offered here, refer to Opal's Multi-Seg function generators.

LFO 1, 2

The controls for Opal's two LFOs are identical.

RATE 1, 2

These knobs set the frequency of oscillation for each LFO. When SYNC is off, the available range is 0.05 Hz to 200 Hz). 

Tip: The Rate knob in the Panel Section is also mirrored in the Display Section. These two controls are linked and you can use whichever is more convenient.

SYNC

This button engages and disengages tempo synchronization. When SYNC is on, the LFO is synchronized to the tempo of the DAW and the LFO frequency values snap to the nearest musical time division. The available range is from 4 bars to 1/128 note.

PHASE

The PHASE knob adjusts the phase offset of the LFO with an available range of 0° – 359°. When set to 0° the LFO has no offset and begins at the beginning of its cycle. A setting of 180° means the waveform begins exactly halfway through its cycle. Other settings start the LFO at various "in between" points in the cycle.

TRIG (Trigger)

Opal's LFOs include a triggering option letting you restart or "retrigger" the LFO's waveform. The drop menu lets you select from the following trigger sources:

• FREE - The LFO runs endlessly and is not retriggered.
• NOTE-ON - The LFO is retriggered when a note is played. 
• LFO 1, 2 - The current LFO is retriggered when the other LFO completes its cycle. Note that an LFO cannot retrigger itself. 
• MULTI-SEG 1, 2 - The LFO is retriggered at the start of each new segment of the Multi-Seg. 

SHAPE

This knob sets the shape of the LFO waveform. Unlike many other synths that have simple LFO waveforms, Opal's LFOs can be smoothly morphed between Triangle, Sine, and Square. These "in between" shapes provide very interesting modulation possibilities.

TILT

This knob lets you introduce asymmetry into the LFO's shape. This can be used to create positive and negative ramps as well as to adjust the duty cycle of a square wave. The default 0% setting will result in a pure triangle, sine or square wave. Adjusting TILT moves the "center" of the waveform left or right, respectively. The LFO display visualizes the result of this change.

Tip: Setting TILT to -100% creates a downward ramp, and 100% creates an upward ramp. Values between -100% and +100% will result in various triangle waveforms. When square waves are selected, TILT changes the pulse width.

RANDOM

This feature introduces random variation into the LFO's wave shape, allowing each cycle to be slightly (or vastly) different from the one preceding it. The RANDOM knob ranges from 0-100% and lets you control the amount of randomness that can occur. At 0%, there is no deviation between cycles whereas at 100% there is maximum random variation.

Tip: If you need an additional Sample & Hold module, set SHAPE to a square waveform and RANDOM to 100%. The LFO will now behave like a S&H module. Selecting other waveforms besides square will provide effects similar to the "random walk" movement.

Sample + Hold

Opal includes a powerful Sample and Hold (S+H) function. You can find this at the right side of the Display when the LFO page is selected in the Panel Section.

SOURCE 1, 2

These two drop menus let you select from the following sources to be sampled by the S&H circuitry. Available sources include:

• RANDOM - A random noise source is sampled.
• LFO 1, 2 - The current position of LFO 1 or 2 is sampled.
• FILTER ENV - The current position of the Filter Envelope is sampled.
• VOLUME ENV - The current position of the Volume Envelope is sampled.
• AUX ENV  - The current position of the Auxiliary Envelope is sampled.
• MULTI-SEG 1, 2 - The current position of Multi-Seg 1 or 2 is sampled.

Tip: Unlike typical sample and hold circuits that sample a single source, Opal allows you to blend between two sources, resulting in patterns that can be more unique and interesting.The two sound sources are blended using the nearby MIX knob before being sampled and held.

TRIG

A Sample and Hold circuit requires a trigger to begin the sampling of an incoming signal and holding the value that has been sampled. This drop menu lets you select from the following options:

• Note-On - The circuit is triggered when a note is played. 
• LFO 1, 2 - The circuit is triggered when LFO 1 or LFO 2 crosses the zero point. 
• Multi-Seg 1, 2 - The circuit is triggered by the gate-outs of the Multi-Seg. 

Tip: When randomness is added to an LFO, not every cycle will cross the zero-point. Therefore, an LFO's trigger output time is randomized as well. Note that LFO synchronization still applies (when it is engaged), so randomized triggers can still be on beat.

MIX

This knob lets you crossfade between the two input sources for the Sample and Hold circuit. Setting the knob to its minimum or maximum position will result in only Source 1 or Source 2 being sampled. Other settings blend the two sources in varying amounts before sampling takes place. For example, a center ("12:00 o'clock noon") setting provides a 50/50 mix between Source 1 and Source 2. The "1" and "2" shown in the display change brightness to visually indicate your mix setting.

 

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Envelope Controls (Filter, Aux, Amp)

Envelopes (sometimes called "ADSRs") let you add articulation to the sound of the synthesizer over time. Opal includes three modeled analog ADSR envelopes called MAIN, FILTER, and AUX.

• The Amp envelope controls Opal's output level.
• The Filter envelope controls the cutoff frequency of Opal's filters.
• The Aux envelope is available as an auxiliary envelope that you can use to control many other parameters in the Modulation Matrix.

Clicking an envelope's header reveals two additional controls: a VELOCITY knob and a GATE SOURCE drop menu. To return to the sliders, click the header again.

Note: The Amp and Filter envelopes are "hardwired" to always control Opal's output level and cutoff frequency of Filters 1 and 2. However, these envelopes can also be used to control other parameters in addition to the hardwired destinations via the Modulation Matrix.

ADSR Sliders

The A, D, S, and R sliders adjust the ATTACK, DECAY, SUSTAIN, and RELEASE components of the envelope.  

Note that Opal's ADSR envelopes are modeled on classic analog designs and have segment shapes and time ranges that deliver an authentic "analog" sound. If you are designing a more complex sound and want envelope segments with specific curves, times, or tempo synchronizations, we recommend using Opal's MULTI-SEGs instead.

• Attack - Adjusts the time required for the envelope to rise from zero to its maximum level when the envelope is triggered.
• Decay - Adjusts the time required for the envelope to drop from the peak of the attack down to its Sustain Level.
• Sustain - Once the Attack and Decay stages have completed, the envelope holds at the level determined by this Sustain slider. The sustain level is maintained as long as a note is held.
• Release - Adjusts the amount of time required for the envelope to return to zero after a key is released.

VELOCITY

Tip: The VELOCITY knob is revealed by clicking the FILTER ENV, AUX ENV, or AMP ENV header text above each envelope. Click the  label again to return to the main view containing the ADSR sliders.

This knob ranges from 0-100% and lets you use MIDI note velocity to scale the amplitude (or "strength") of the envelope. At the minimum (0%) setting, note velocity has no effect on the envelope scaling and the envelope always plays back at full scale. At the maximum (100%) setting, note velocity has the maximum possible effect on the envelope scaling and the envelope is at its most "velocity sensitive."

GATE SOURCE

Tip: The GATE SOURCE menu is revealed by clicking the FILTER ENV, AUX ENV, or AMP ENV header text above each envelope. Click the  label again to return to the main view containing the ADSR sliders.

This drop menu determines what events trigger (or retrigger) the envelope. The default NOTE-ON selection means that incoming MIDI notes start the envelope. The following options are also available:

• LFO 1 - The envelope is triggered when a note is played and retriggered when LFO 1 completes its cycle.
• LFO 2 - The envelope is triggered when a note is played and retriggered when LFO 2 completes its cycle.
• MULTI-SEG 1 - The envelope is triggered when a note is played and retriggered when a new segment begins playing in MULTI-SEG 1.
• MULTI-SEG 2 - The envelope triggered when a note is played and retriggered when a new segment begins playing in MULTI-SEG 2.

 

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Output/FX Module Controls

The Output module is the last stop of the Opal signal path. Here you can adjust the output volume and stereo panning, as well as configure output effects such as reverb and delay to further sweeten your sounds. Opal has two identical effects slots that can load a variety of high quality algorithms developed by Universal Audio's renowned DSP scientists. To give you maximum flexibility, you can route your signals through the effect slots in several different ways, as described below.

FX 1, 2

These knobs adjust the intensity for each of the two output effects. 

• If an effect is routed serially, this knob functions as a wet/dry control and sets the balance between the original and processed signals. In the minimum position (fully counter-clockwise), none of the signal is sent to the associated effect and the output is 100% dry. When rotated fully clockwise to the maximum position, 100% of the signal is sent into the effect and you only hear the output of the effect (100% wet). When the knob is set to the center ("12:00 o'clock noon") position, you will hear a 50/50 mix of dry and processed sound.
• If an effect is routed in parallel, this knob sets the "send" amount from 0-100%. In the minimum position (0%), none of the original signal is sent into the effect and only the dry signal is heard. When set to the maximum position (100%), all of the original signal reaches the effect and a heavily processed effect is heard on top of the original sound.

Note: The FX knobs on the Panel Section are linked to the AMOUNT sliders in the Display Section. Rotating a knob will cause the mirrored slider to move, and vice-versa.

Pan

This slider sets the stereo positioning of Opal's output. 

Note: Output FX 1 and FX2 are returned after panning, so the sound from your Output FX (particularly reverbs and delays) will still be heard in stereo even if you have hard panned Opal's output to the left or right.

Volume

This knob sets the output level of Opal.

Output FX Selector

 

This drop menu lets you choose from Opal's available Output effects. These effects are described in detail in the Output Effects Controls section of this guide. 

FX Controls

These sliders adjust four parameters of the effect that is currently loaded. The labeling and function of these sliders varies depending on what effect is loaded. Refer to the Output Effects Details section to learn more about each parameter.

Effects Routing

This drop menu lets you select how the signals will be routed through the output effect slots. A signal flow diagram is shown in the display to help you understand each option.

Series-Series

Signal flows serially from FX1 to FX2.

Series-Parallel

Signal flows serially through FX1 but in parallel through FX2.

Parallel-Back

Signal flows in parallel through FX1 but serially through FX2.

Parallel-Series

A parallel signal path that flows through both FX1 and FX2.

Parallel-Parallel

A parallel signal path flows independently through FX1 and FX2. 

 

 

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Modulation Matrix Controls

Opal's Modulation Matrix lets you connect various sources (such as LFOs or Envelopes) to desired destinations (such as oscillator pitch or filter cutoff frequency). This lets you create sounds that are more complex than what can be achieved using only the hard-wired connections. This page is accessed by clicking the MATRIX button near the top right of the instrument. Modulation routings are created by making selections from the Source and Destination drop menus.

Opal Block Diagram

The illustration below shows Opal's hard-wired modulation routings, as well as routings available through the Modulation Matrix.

Note that certain commonly used controls including the Filter and Amp envelopes are "hardwired" and linked by default so they do not need to be set in the Modulation Matrix. While a handful of controls are connected by default, there are dozens of other sources and destinations that you may want to link together as you design sounds.

Opal's Mod Via feature even lets you modulate a connection itself with another modulator, for example, using key velocity to make a modulation link velocity sensitive.

You can set up to 16 modulation routings for highly complex sounds.

+ (add) and X (delete) buttons

These buttons create and delete modulation routes. The + button at the top-left creates a new route while the X (at the right of each route) deletes that route.

Mute

This button mutes and unmutes its associated modulation link. When muted, the button is lit and the modulation link is inactive (the source has no effect on the destination).

Tip: Modulation muting can be very helpful when troubleshooting complex sounds that you have designed or when trying to understand the sound design work of others.

Source

This drop menu selects the control source of your modulation route. You can choose from the following sources:

Amount (Source)

This slider adjusts the amount of the modulation source from ±100. When set to the middle (0) position, the modulation source is off. Moving the slider to the right of center increases the scaling of the "positive" modulation on the destination. Moving the slider to the left of center increases the scaling of "negative" (inverted) modulation.  

Tip: Opal's modulation ranges are limited by design in order to make them easier to dial in. However, if you would like a wider modulation range you can create two modulation routes to the same destination. This lets you "double up" on the modulation.

Offset

This slider lets you introduce a positive or negative offset to the modulation source. For example, if an LFO is selected for a modulation source, this slider will shift the entire LFO above or below the central "zero crossing" line. The default central position (0) means that no offset is applied. Moving the slider to the right of center increases the positive offset while moving the slider to the left of center increases the amount of "negative" offset.  

Tip: Opal's LFOs are naturally bipolar whereas Multi-Segs are unipolar, but you can use the Offset to create unipolar LFOs or bipolar Multi-Segs. Offsets are also handy when creating macro controls for your preset since, for example, you may want the default position of your Macro knob to be different from that of the control you wish to control.

Mod Via

This drop menu lets you adjust the strength of a modulation route with a secondary modulator. For example, you can use note velocity to adjust the strength of a vibrato effect.

Amount (Mod Via)

This slider adjusts the scaling of the MOD VIA parameter from ±100. When set to the middle (0) position, the MOD VIA source is off. Moving the slider to the right of center increases the scaling of the "positive" modulation on the destination. Moving the slider to the left of center increases the scaling of "negative" (inverted) modulation.  

Destination

This drop menu selects the destination of your modulation link.

How to Use the Modulation Matrix

The Modulation Matrix may seem complex at first, but it is actually simple and quick to configure after you've made a few modulation routings. The process is as follows:

1. Start by selecting a modulation source from the SOURCE drop menu.
2. Next, select the target of your desired modulation in the DESTINATION drop menu.

You have now created a modulation route! For example, if you select "LFO1" as a source and "FILT1 CUTOFF" as the destination, LFO1's output is now controlling the first filter's cutoff frequency. You can still adjust the filter's cutoff frequency by hand if you wish, but the LFO's output is also having an effect on the filter's cutoff.

If the other controls are in their default positions, you may notice the effect is either too subtle or too intense. This is normal. In many cases, it's possible for the default settings to result in a modulation link that is either very subtle or highly exaggerated. You can fine tune the modulation routing using the AMOUNT slider.  

• Use the AMOUNT slider to adjust the scaling ("strength") of the effect that the source has on the destination. A setting of 100% means that the source will have its maximum possible effect on the destination. A setting of 0% means that the source has no effect on the destination. You can also rotate this knob counterclockwise to reach negative numbers up to -100%. Doing so will cause the source to have an inverted effect on the destination (an increasing LFO wave will cause the filter cutoff frequency to decrease, and vice-versa.)

The OFFSET slider is to the right of the AMOUNT slider.

• The OFFSET slider introduces a deliberate offset to the starting position of your modulation source. This lets you shift the source's waveform or value up or down. The default 0.0 setting means that there is no offset applied (a sine wave LFO would swing around its natural zero crossing point). Moving the slider to right of center means that a positive offset is applied while moving the slider left of center means that a negative offset is applied (the center of that sine wave LFO is shifted above or below the natural zero crossing).

At this point we have covered all of the basics that are commonly found in the modulation matrices of various synthesizers. Opal's Modulation Matrix has a few extras that can help make sound design easier and more interesting.

• The "M" button lets you quickly mute and unmute the modulation link to hear the effect of your routing. This is very useful, for example, when troubleshooting complex sounds because it saves you from having to move the AMOUNT slider to zero and back to its previous setting each time.

• The MOD VIA controls open up new and powerful sound design options. This section lets you modify your modulation amount (what we created in steps 1-2 above) by using another modulator. For example, selecting "Velocity" in the drop menu lets you use the MIDI velocity information of your played notes to scale the modulation amount itself. This lets you make velocity sensitive modulation routings in which soft notes have very little modulation whereas loud notes have a more pronounced effect. To use this, select a secondary modulator from the MOD VIA drop menu. The nearby AMOUNT slider works in the same way as the AMOUNT slider described above (see step 3).

 

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Multi-Seg Controls

Opal has two powerful Multi-Seg (multi segment function generators) that can be used as envelopes, LFOs, step sequencers, and more. The two Multi-Segs are identical and the output of each multi-seg can be used as a source in the Modulation Matrix just like an LFO or envelope. 

Unlike traditional LFOs and envelopes, Multi-Segs are not limited to basic wave shapes. Each Multi-Seg has up to 32 distinct segments and you can program each segment with its own level, shape, and playback rate. This means you can easily create highly complex modulations with only a few mouse clicks.

Accessing the Multi-Segs

To access Opal's Multi-Seg controls: 

1. Click the Multi-Seg header or selector button in the Panel Section to bring up the Mult-Segs in the Display Section. 
2. Click one of the tabs on the left side (labeled 1 and 2) to select Multi-Seg 1 or Multi-Seg 2. The rest of the display now controls your chosen Multi-Seg.

Speed

This control scales the rate of the entire Multi-Seg (all segments). With this convenient feature, you do not have to adjust every segment manually to hear a change. For example, when SPEED is set to 1, each segment within the Multi-Seg will play back at 1.0x (i.e., each segment will play back at the RATE you have set for that segment). Changing SPEED to 2x will result in all segments playing back at double-time (i.e., each segment plays at twice the value of what you have set using the RATE control).

Note: The SPEED control mirrors what is shown on Opal's Display Section. Changing a setting here will cause the Display Section control to update, and vice-versa. 

 

Multi-Seg Display Components

Sync

This button engages and disengages tempo synchronization for its associated Multi-Seg. If SYNC is disengaged, the SPEED and RATE knobs can be smoothly adjusted to any value from 0.25x to 32x. When SYNC is engaged, the SPEED and RATE knobs snap to exact multiplier values that maintain precise sync with the DAW's tempo (i.e., a looped Multi-Seg will remain in sync to the tempo of the DAW and will not drift out of sync over time).

Loop

This button engages and disengages Multi-Seg looping. 

Loop/End marker

 

• When looping is engaged, the Multi-Seg automatically restarts after reaching the Loop/End marker in the display. You can adjust the loop point by dragging the Loop/End marker.
• When looping is off, the Multi-Seg plays through its sequence and stops after reaching the Loop/End marker. You can adjust the loop point by dragging the Loop/End marker.

Tip: When looping is engaged, a Multi-Seg functions like an LFO or sequencer. If looping is disengaged, the Mult-Seg behaves like an envelope.

Trigger Source (Trig)

This drop menu selects what event will start (or restart) the Multi-Seg.

• FREE - The Multi-Seg will run continuously in Loop mode.
• NOTE-ON - The Multi-Seg plays or restarts any time a note is played.
• LFO 1, 2 - The Multi-Seg plays or restarts when LFO 1 or 2 completes its cycle.
• MULTI-SEG 1 (or 2) - A Multi-Seg plays or restarts when the other Multi-Seg completes its cycle.

Segment Selector

Multi-Segs can have up to 32 segments. The current segment number is listed at the top of the segment controls and is highlighted in the display. The left/right arrows can be used to select the previous/next segment. You can also select a segment directly by clicking its control point (white dot) in the display.

Segment Level

This knob sets the level of the selected segment's control point, from 0-24. Levels are set in quantized, semitone steps to make setting pitches easy (for example, when using a Multi-Seg to control an Oscillator's pitch). You can change segment levels using the LEVEL knob or by dragging a segment's control point up or down.

Note: Holding shift while dragging the LEVEL knob or a control point switches off quantization and lets you select your level values with greater precision. 

Segment Rate

This knob lets you set the playback speed of the currently selected segment. You can also change a segment's playback speed by dragging its control point left or right.

Note that if SYNC is disengaged, this control can be smoothly adjusted to any value from a (very slow) 1/16 to "Instant". When SYNC is engaged, the Multi-Seg segments are synchronized to the tempo of the DAW and the RATE knob displays values in musical time divisions ranging from "4 bars" to "Instant".

Note: This parameter controls the playback rate of the current segment, as indicated by the SEGMENT SELECTOR. To control the overall playback speed of all segments within a Multi-Seg as a whole, use the SPEED control instead.

Segment Curve

This knob sets the shape of each segment. The default setting of 0 results in a straight line connecting the segment's control point to the previous segment's control point. Rotating this knob clockwise creates a concave curve whereas rotating counter-clockwise creates a convex curve. Setting this knob to its minimum or maximum results in a discrete "stair step" change with the change at the start (-100%) or the end (100%) of the segment. You can use this along with GATE OUT to convert a Multi-Seg into a step sequencer with up to 32 steps.

Tip: You can also change a segment's shape by left/right dragging the smaller control point that appears when you hover the mouse over a segment.

Segment Gate

Each segment of a Multi-Seg generates a gate signal that can be used to trigger (or retrigger) various other modules within Opal.  For example, you can have each new segment trigger (retrigger) an envelope by selecting "Multi-Seg 1" (or "Multi-Seg 2") from the Envelope's GATE SOURCE menu. The GATE OUT knob sets the gate length from 0-100% of the associated segment. 

Tip: You can also change the gate length of any segment by adjusting the small horizontal sliders at the top of the display.

Load Template

This drop menu includes a number of useful Multi-Seg templates that can be used as-is or modified to suit your needs. Click any of the available templates to load it.

Copy, Paste

These buttons let you copy and paste the data contained within the Multi-Seg. This lets you quickly duplicate the contents from one Multi-Seg into the other without having to manually re-program each step. You can also copy contents from another preset into your own. To do this, click COPY on the source Multi-Seg and PASTE on the destination Multi-Seg.

Note: Copying and pasting works within the same instance of Opal. If you would like to copy the Multi-Seg contents from a different preset into your own preset, remember to save your preset before loading another preset.

Display

The Multi-Seg shape and function is displayed here in graphical form. 

• You can select segments for editing by clicking on their control points. The currently selected point is shown in white and the RATE, LEVEL, SHAPE, and GATE OUT knobs can be used to edit that segment's parameters.
• You can also edit a segment directly by its control points. Moving a point up/down changes its LEVEL while moving it left/right adjusts its RATE. Hovering the mouse between points reveals a smaller point at the midpoint of the connecting line. This smaller point can be dragged left or right to adjust the segment's SHAPE parameter. Finally, the GATE OUT parameter can be edited by dragging the small horizontal slider above the segment.

Horizontal Scroll/Zoom bar

The horizontal bar at the bottom of the Display lets you zoom into your Multi-Seg and scroll left/right so that you can make more precise edits.

• To zoom in or out, drag the triangular icons at the ends of the bar.
• To scroll, drag the center of the bar left and right. 

Adding/Deleting Segments

To create a new segment, double-click a control point. This will add a new segment to the right of that control point. You can also click the + icon at the right side of the display to add a new segment to the end of the Multi-Seg. 

To delete a segment, double-click its control point.

Note: If you have zoomed in and the + sign is no longer in view, use the horizontal bar at the bottom of the display to scroll (or zoom out) to reveal the + sign. The + icon disappears when 32nd segments have been created (Multi-Segs can have up to 32 segments).

 

 

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Output Effects Controls

Opal includes many Output effects that are developed by Universal Audio's renowned DSP scientists. These effects are used at the end of the voice path (in the Output module) to sweeten and polish Opal's overall output. The effects are selected from the drop menu in the Output module and come in six categories.

Note: There is a key difference between an Output effect and an Insert effect. With an insert effect, each voice has its own separate instance of that effect (i.e., each voice is processed independently). With an output effect, all voices run through the same effect and all voices influence each other while being processed. This has the effect of "gluing" sounds together and making them sound more cohesive overall.

EQ/Compress

These effects let you equalize and compress Opal's output. 

EQ

A single-band, morphing equalizer. Useful for giving a frequency contour to your overall output.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Freq - Sets the corner frequency of the EQ.
• Boost - Sets the boost or cut amount of the EQ.
• Mode - Determines the shape of the EQ. This can be morphed from low-shelf, to parametric, to high-shelf.

Comp 76 Basic / Comp 76 Slam

Comp 76 Basic is a classic Universal Audio compressor. The "Slam" version of this effect is the same classic compressor with its famous "all buttons in" mode engaged. 

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Input - Adjusts the input gain of the compressor. Increasing the input results in more signal exceeding the threshold and being compressed.
• Release - Sets the release time of the compressor.
• Output - Adjusts the output level of the compressor.

Delay Effects

Opal's Delay effects provide "clean" and "accurate" echoes for a more modern sound. For a more saturated tone with more character, use the Tape Delay effects.

All of the Delay effects have the same four controls:

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Time - Sets the delay time of effect. When the BPM version of this effect is used, the delay time of this effect is set in note values based on the DAW's current BPM.
• Feedback - Determines how much of the output is sent back to the input, from 0-100%
• Bright - Adjusts a low-pass filter used to darken the delayed signal.

Delay Mono / Delay Mono BPM

A medium length delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Delay Stereo / Delay Stereo BPM

A true-stereo delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Delay Ping Pong / Delay Ping Pong BPM

A stereo back/forth bounce delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Delay Fast-Mod

A delay with rapid modulation.

Tape Delay Effects

Opal's Tape Delay effects include tape saturation and filtering for more character. If you would like very precise echo effects, use the regular Delay Effects (described in the previous section).

All of the Tape Delay effects have the same four controls:

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Time - Sets the delay time of effect. When the BPM version of this effect is used, the delay time of this effect is set in note values based on the DAW's current BPM.
• Feedback - Determines how much of the output is sent back to the input, from 0-100%
• Bright - Adjusts a low-pass filter used to darken the delayed signal.

Tape Delay Mono / Tape Delay Mono BPM

A tape emulation mono delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Tape Delay Stereo / Tape Delay Stereo BPM

A tape emulation stereo delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Tape Delay Ping Pong / Tape Delay Ping Pong BPM

A tape emulation back/forth bounce delay. The "BPM" version of this effect includes a time knob that is synchronized to the DAW's tempo.

Harmonic Effects

Harmonic effects can be used to bring out overtones for added excitement.  These effects can be set to bring everything from slight fuzz to heavy distortion.

Overdrive

A more gentle type of distortion, comparable to overdriving a guitar amp. Signals exceeding the threshold are rounded off more gradually resulting in a distortion that is less "bright" and contains less high frequency sizzle.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Drive - Adjusts the input gain of the effect and determines how much of the incoming signal will exceed the threshold and be affected.
• Offset - Introduces a DC offset to the incoming signal to create asymmetric distortion. When set to the center position, there is no DC offset. Rotating the knob right of center introduces a positive offset while rotating to the left of center introduces a negative offset.
• Output - Adjusts the output level of the effect. Use this to attenuate an overly loud output or to provide make up gain if the output has been reduced by the effect.

Distortion

A hard clipping distortion effect with aggressive flattening of the waveform peaks.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Drive - Adjusts the input gain of the effect and determines how much of the incoming signal will exceed the threshold and be clipped.
• Offset - Introduces a DC offset to the incoming signal to create asymmetric distortion. When set to the center position, there is no DC offset. Rotating the knob right of center introduces a positive offset while rotating to the left of center introduces a negative offset.
• Output - Adjusts the output level of the effect. Use this to attenuate an overly loud output or to provide make up gain if the output has been reduced by the effect.

Modulation Effects

These effects allow you to animate static sounds by using Opal's modulators to create a sense of movement and motion. To do this, use the Modulation Matrix to bring any modulation source (like simple LFOs or highly complex Multi-Segs) to the TIME parameters described below.

Comb-Flanger

A comb filter that can be transformed into a flanger by using modulation. By default, this effect is a static comb filter with fixed filter frequency. However, by applying modulation to this effect's TIME parameter, you can transform the filter into a flanger with its characteristic swirling and swooshing sounds. This is done by routing a modulation source (such as an LFO or Multi-Seg function generator) to the first parameter of the effect in the Modulation Matrix.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Time - Sets the delay time of the duplicated signal in the comb filter. Modulating this parameter with an LFO will provide classic flange and chorus effects.
• Feedbk - Adds intensity to the effect by setting how much of the output is sent back to the input, from 0-100%
• Damp - Adjusts a low-pass filter to darken the delayed signal.

Notch-Phaser

This effect is similar to the Comb-Flanger, except that it uses an all-pass filter to create a series of notches spread across the frequency spectrum. By default this effect is static resonance, however, by applying modulation to this effect's FREQ parameter, you can transform the filter into a Phaser. This is done by routing a modulation source (such as an LFO or Multi-Seg function generator) to the first parameter of the effect in the Modulation Matrix. 

Phasers sound similar to Flangers, but tend to be more subtle in their effect. 

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Freq - Sets the cutoff frequency of the notch filter.
• Res - Sets the filter resonance amount of the notch filter.
• Spread - Determines the interval spacing between the notches.

 

Ensembler Mono / Ensembler Stereo

This effect uses multiple modulated delay taps to create a rich sound, like a cross between a pitch shifter and a chorus. The stereo version of this effect has taps staggered throughout the stereo field, which results in a swirling effect.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Rate - Adjusts the frequency or "speed" of the built-in modulator.
• Depth - Sets the "depth" of the effect, from mild to exaggerated.
• Shape - Sets the shape of the built-in modulator's waveform. The minimum setting results in a triangle waveform which creates a detuning effect while the maximum setting results in a sine wave with a chorus effect.

Reverb Effects

Reverbs are commonly used to add ambience and place a sound into a space, but they can be used in creative ways as well (for example, to create washes of sound!)

The Hall, Ambience, Cathedral and Room reverbs share the following controls:

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Size - Adjusts the size of the hall.
• Prox - Sets the distance between the sound source and the listener in the hall.
• Bright - Adjusts a low-pass filter used to darken the reverb tail.

Hall

A concert hall reverb.

Ambience

Provides ambience of a large hall.

Cathedral

A reverberation in a cathedral

Room

A reverberation in a small to mid-sized room.

 

Spring Short / Spring Long

A spring reverb with short or long decay times.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Pre-Dly - Sets the pre-delay time before the signal reaches the spring. 
• Treble - Adjusts a high frequency shelving EQ.
• Bass - Adjusts a low frequency shelving EQ.

Alienverb

An otherworldly reverb designed to be modulated in strange ways. This unusual reverb can be modulated very quickly (audio rate) and has positive feedback allowing it to saturate like a tape delay. Results can range from realistic to "tank-y" or "comb filter-ish" in nature.

• Amt - Adjusts the intensity of the effect. A minimum setting results in a dry sound with no effect. A maximum setting results in a heavily processed sound.
• Size - Adjusts the reverberating room's size. Can be modulated at audio rate.
• Feedbk - Determines how much of the output is sent back to the input, from 0-100%
• Bright - Adjusts a low-pass filter to darken the reverb tail.

 

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MIDI Continuous Control and Automation

Opal has a straightforward user interface, but we've included some powerful automation features under the surface. Having access to automation and MIDI CC control can make life easier during a live performance (for example, changing parameters "on the fly" from your MIDI controller without looking at your computer). It can also open up creative sound design possibilities during a mix.

Global Controls

Parameter	MIDI CC number
Macro Knob 1	16
Macro Knob 2	17
Macro Knob 3	18
Macro Knob 4	19
Note Trigger Mode	68
Glide Amount	5
Glide Trigger Mode	84

Oscillator Section

Parameter	MIDI CC number
Oscillator 1 Shape	26
Oscillator 1 FM amount	70
Oscillator 2 Shape	27
Oscillator 3 Shape	28
Noise Color	29

Mixer Section

Parameter	MIDI CC number
Oscillator 1 Level	85
Oscillator 2 Level	86
Oscillator 3 Level	87
Noise Level	89

Filters and Filter Envelope

Parameter	MIDI CC number
Filter 1 Cutoff Frequency	74
Filter 1 Resonance	71
Filter 1 Envelope Amount	25
Filter Envelope Attack	22
Filter Envelope Decay	23
Filter Envelope Release	24

Master Output and Amp Envelope

Parameter	MIDI CC number
Amp Envelope Attack	73
Amp Envelope Decay	75
Pan	10

LFO Section

Parameter	MIDI CC number
LFO 1 Rate	76
LFO 1 Tilt	79

Output FX Section

Parameter	MIDI CC number
FX 1 Amount	91
FX 1 Parameter 1	12
FX 1 Parameter 2	13