Overview of Out-of-the-box Instruments and Effects

Sound Generators

To audition sounds without a physical controller, use Audio Production/Midi Utilities/JACK keyboard Be sure JACK is running first. Follow the instructions below to connect the virtual keyboard, and use the mouse to play a few notes.

Start up QjackCtrl, then from the main Ubuntu menu, select Audio Production/Sound Generators, to see a list of pre-installed virtual instruments.


A list of eleven plugins appears (far right menu), with “Extra Sound Generators” at the top. We'll start with Hexter, Yamaha DX7 emulator that is also reminiscent of an early eighties Casio keyboard. Click on Hexter, then in JACK, click “Connections”. Go to the audio tab and connect Hexter's audio output to System by click-dragging a line between the two (see screentshot below). Use Hexter's “Send Test Note” button to check that the audio connection is working (bottom of left panel in following screenshot). If there is a problem, check the volume levels, then review JACK's configuration. Next, use the MIDI tab, open the left and right dropdown menus (here labeled “aj2”) to connect your controller's MIDI output to Hexter's MIDI in by drawing a line between them – drawing in either direction will work.


In Hexter's clean interface, it's easy to find a patch, and the patches are familiar sounds like marimba, clavinet, and synth brass. Screenshot 3.2 shows the surprisingly punchy patch, Growler, selected – be sure to give it a try along with other Hexter patches.

You can connect the other instruments in JACK the same way, but some of them may require additional setup, including connecting the MIDI out from your controller, which may appear in JACK's ALSA tab under the aj2 drowdown menu rather than under the MIDI tab where you would expect to find it. Let's continue the tour with an eye towards making sure everything plays.

If you select P, the Principle manual, to respond to MIDI channel 1, then it's possible to toggle the other manuals viaaeolus' buttons labeled “P+I”, “P+II”, and “P+III”. This is helpful if you are only using a single controller and solves the problem of some stops appearing not to work.

Aeolus is a pipe organ emulator whose gorgeous sound compensates for a notably drab Graphical User Interface (GUI, pronounced “gooey”). When you launch Aeolus, all of its buttons flash in sequence. On older versions of Ubuntu Studio, it was necessary to install an additional helper program to run Aeolus. There is no default sound, and you must click “Recall” to get to the first preset. Depending how Aeolus is set up, you may notice that enabling and disabling some stops doesn't change the sound. Clicking on the MIDI button opens a grid where you can assign a different MIDI input channels to manuals P, I, II, or III. Remember to set the MIDI send channel accordingly on each controller (assuming you have more than one tier of keyboards).

For what it lacks in pizazz, the rest of Aeolus' operation is clear – use Prev and Next to page through a handful of presets. You can make fine adjustments to tuning, tremelo, and swell via the “Instrum” button, and “Audio” has sliders for volume, delay, reverb, and a few other parameters.

Pictured below is synthv1, an unassuming polyphonic analog synthesizer with 28 presets and a convenient waveshaping interface that allows you to sculpt the sound by clicking and dragging. It's possible to add nodes to the graphs as well. Connect it in JACK and you will see it has the classic fat analog sound. If all the knobs and initials appear daunting, please refer to chapter 10 for an introduction to creating sounds with any synthesizer.


Ubuntu Studio comes with three more “gray panel” synths pre-loaded: samplev1, drumkv1, and qsynth. See following screenshot.

Drumkv1 (top left), Qsynth (top), and samplev1 (bottom) share a common look and feel with synthv1.

Qsynth is a soundfont player. Somewhat of an older format, soundfonts are a convenient way to package samples and map them to MIDI note events, effectively building your own instruments. Qsynth does not come with any preloaded soundfonts, but there are many resources for free soundfonts online. Two different patches can be loaded and triggered simultaneously to create a layered effect, using Qsynth1 and Qsynth2. Drumkv1 and samplev1 also require wav files to be imported. We'll look at importing sounds to Qsynth when we cover making your own soundfont. For now, let's note that samplers represent one way to get high-fidelity instruments (with some trade-off between sample size and quality) and continue the tour of out-of-the-box plugins.

Amsynth has a brighter, almost harsh sound compared to Qsynth. This one is also polyphonic and comes with over 20 banks, each containing tens of powerful presets. The virtual keyboard may crash amsynth, but other than that, it's stable and quite an analog beast.


This brings us to one my favorite native Linux synthesizers, Yoshimi. It boasts a simple interface and its sounds are a step up from Hexter, including some of the best bell tones you'll find. Yoshimi's virtual keyboard works without needing to enable it in JACK. To try the onboard effects, use the “Insertion Efx” tab and select “Master Out”. Under “Panel” (next to the pink reset button in the screenshot below), you can set up to 16 MIDI channels with different sounds.


To get even more soft synths for Ubuntu Studio, first try “Audio Production/Sound Generators/Extra Sound Generators” - you should see a dropdown list of additional plugins to try out. Some of these cover similar territory to the ones we've already tried out, some may not have the best GUI. A handful more are listed in Ubuntu's Software Center – of those, don't overlook FOO, a bright red electric organ emulator. Here is a page that lists 73 synth plugins that run natively on Linux: http://linuxsynths.com/index.html. But...there are more free plugins for Windows than you could ever download, and only two programs are needed to run them (see chapter 5).

Ubuntu Studio comes with the Hydrogen drum machine pre-installed – it's in the main “Audio Production” menu. This is a fairly deep program, so I recommend taking the time out to review the User Manual found under the Info tab. If a drum machine is any good, it will perforce be complex, as there are so many facets to creating a rhythm track. The good news is that most drum machines take similar strategies to addressing this complexity. You need a way to pull in sounds and organize them as a drum kit, a way to create patterns for the various parts of a song - intro, A, B, fills, coda, etc. - a way to tie these together, and, if we're lucky, save and export in multiple formats. Transport controls for real-time recording, and a grid for step recording (where events are added graphically via mouse click), and quantization (to keep individual hits where they belong), round out the basic functions to look for in any drum machine. The main distinction between programs is how user-friendly (or user-hostile) they are, and by keeping the GUI simple, Hydrogen excels in ease-of-use.

The main menu has a slick LED clock, transport buttons, tempo selector and buttons to open a mixer (used to adjust the balance between sounds in a kit, if needed) and the instrument rack. Try the [+/-] increment/decrement buttons next to the BPM readout – this is how to adjust the tempo. If you are recording in real-time, the speaker icon just below [+/-] toggles the metronome, so you can record to a click (these three buttons are stacked in the middle of the following screenshot).

Hyrdogen's main menu

Directly beneath the main menu is the song section, where patterns can be chained together. The next screenshot shows a song that uses five distinct patterns, labeled on the left menu. Clicking a box in the grid turns it blue for a given pattern. So the four blue boxes next to pattern 1 will – you guessed it – play that pattern four times. And so on for the other patterns. Note the loop button in the transport window will keep the song playing if you have all the parts and don't feel like copy-pasting them. This can be good for real time recording and live performance, as we'll see in the next section.


Before creating a song, you'll need to make some patterns. Open and save a new project. Clicking in the pattern grid will leave a black dot where an event should be triggered. You can work on this in real time by enabling looping and turning on the click in the main menu as mentioned earlier. Work your way up the kit adding and removing triggers by clicking. By creating a very simple pattern at first, you can then copy it to introduce additional parts. This will come in handy as you stitch the patterns together in the song editor. As you can see, I made two copies of Pattern 1, displayed as Pattern 1#2 and 1#3. Pattern 3 is this song's ending, a tom roll and cymbal crash. 3.12_HydrogenPattern.pngHydrogen's pattern editor. Note the mute and solo buttons next to each instrument – these button might be used with looping enabled to add variety to beats during a live performance.

The last panel has quite a few goodies in store – a way to edit the sound of individual instruments, and best of all for those of us with an insatiable appetite for sounds, a varied library of kits that can be swapped in for a given pattern. Not only that, you can upload your own sounds. Merely changing the kit can have a profound effect on a drum pattern's sound. Hydrogen is a highly adaptable workhorse of a drum machine with a GUI that is more intuitive than most other free drum machine plugins.

3.13_HydrogenControlPanel.pngControls for editing instruments and changing out the drum kit (Sound Library).

Hopefully this overview leaves you with a song made up of a couple of patterns. Refer to the on-board user manual for more detailed information on quantization, setting the tempo via tap tempo, exporting your song as an audio file, piano mode for triggering notes, and many other features.

If you're like me, launching a new synth is like getting a new toy, and you may find yourself auditioning presets into the wee hours. So far we have analog and FM synthesis covered, which covers bass, chords, and leads (duties that can be shared with electric guitar). Our virtual band also has drums.

But what about a really good piano?

I recently spotted a forum comment where someone complained that Ubuntu Studio does not lend itself to “just sitting down to play the piano”. While we're only using out-of-the-box, native Linux instruments, the best answer is probably to download a piano soundfont to use with Qsynth. But as noted previously, there is a trade-off between sound quality and the size of a sample. Linux compatible Pianoteq 6 starts at $130 and has a 50MB footprint. A smaller-sized, free piano sample may loop the fade-out of a note to minimize the soundfont's overall footprint. The bottom line is that it's often best to simply record a real instrument, such as a digital or stage piano. As for the commenter who just wants to play piano and doesn't want to deal with configuring software on his computer, it sounds like he should rescue an old acoustic piano and leave it at that! Your soundcard should be able to accept microphone input. So, if you have one, your ultimate “piano patch” might well be a real piano. But don't despair: once we learn how to run Windows-only VST plugins in chapter 5, you'll have your pick of pianos - see the appendix for some links.

http://www.pianoteq.com – a native Linux piano.

Audio Processors

Ubuntu Studio comes with an insane number of effects and signal processors. I will only cover two guitar effects plugins here, and we'll see more about effects when we talk about recording.

Guitarx is labeled as a “simple mono amplifier simulation”, but it is comparable to other amp models, with the ability to add rack units to your heart's content. I am not a guitar player, and have no stomp boxes or dedicated guitar amp. But even if you have a great live rig, plugins are just simpler to set up and use for digital recording. Are the eighteen different “Tube” settings are dead ringers for their namesakes? Does “Twin” really sounds just like a Fender Twin Reverb amp? Only you can decied, but t is very simple to go from a little crunch to a searing lead to a clean, slow tremolo. Click “Plugins/Plugin bar” and the entire gamut of effects is displayed. To add a rack unit from this selection, just double click. Throw the toggle switch on the left side of the unit to make it's LED light turn green, then adjust the knobs to your liking. To remove a rack unit, simply double-click one of the “screws” on its front panel.

Skeuomorphic design – where one material, say plastic, is made to look like another, such as wood grain - has been around too long and there has been some criticism of it's use on virtual instruments. Yet the green brushed metal and chunky black knobs of guitarx make for a GUI that looks - and is - ready to rock. Set your sound card for monaural instrument input and make sure guitarx's output connects to System in JACK, then try the three banks of presets to get a feeling for guitarx's strengths.



If you like to chain effects together as in a pedal board, Rakarrak is the plugin for you. I won't try to describe it's three banks of 60 presets each (plus a user bank!) other than to say Rakarrak is one of my favorite things to play around with in Ubuntu Studio. You can just park it on any preset and start fiddling with parameters to radically alter the sound.

Once you load and connect it, click “FX On” so that it lights. The I/O faders default to 50-50, so you may want to adjust that balance to ensure the effect is all you hear. But first, set FX% to zero with FX On, and enable the Tuner in the top right-hand column. When you strike a note, the tuner displays it. As you work the tuning pegs on your guitar, the pitch meter will show fine tuning between sharp and flat. Even if you have another guitar tuner, this one proves very handy when recording on the computer.

Rakarrak can turn your electric guitar into a MIDI controller. If you've ever wanted to play a guitar synthesizer, now you can control virtual instruments...with no extra gear!

Just below the Tuner, you'll see a MIDI section, something you might overlook while browsing presets, jamming, and cooking up your own blend of effects. Open one of the synths we've tried, such as amsynth, and enable MIDI in Rakarrak. You will see Rak' as an available MIDI source in JACK – just connect it to your synth plugin as any other controller, and – voila! - guitarists now have a whole new world of crazy sounds at their disposal. You may notice a bit of latency or delay between striking a string and hearing the note played back on the synth. The degree of this issue may vary from one sound or synth to the next. A quick fix to fill out your sound is to turn the Input fader back up a bit, as long as you don't mind layering the guitar sound with the synth patch you've chosen. Another problem is unwanted ghost notes. You can try adjusting the velocity and trigger settings in Rakarrak's MIDI section, but depending on what you're after, the stray notes can take on a surprisingly convincing arpeggiator character. In general, mono, lead sounds work well, and sounds like organ can take on a more mechanical sound when controlled from a fretboard. Linux musicians tend to be experimentalists, and to that end, I highly recommend trying Rakarrak's MIDI feature. Performance issues might be better or worse depending on your hardware, the plugin, and even the particular patch.

Rakarrak set to one of the author's favorite presets. Tuner and MIDI sections are in the upper right.

ToneLib GFX

Ubuntu Studio 20.04 includes a 30 day evaluation copy of ToneLib GFX, which has a straightforward pedalboard layout where you can click and drag thumbnails of effects boxes to add or reorder the chain to quickly craft the sound you want. As can happen with physical gear, there can be serious hum even when the guitar is not plugged in, and depending on your instrument, the hum can be beyond annoying. ToneLib GFX has a noise reducer that gets this problem under control. ToneLib_GFX.png

Tools & Utilities

There are a few things to be aware of under the Audio Production “MIDI Utilities” and “Mixers and Card Control” menus but feel free to return to this section later and go to the next chapter if you are itching to start recording. The recording software we'll be focusing on has an excellent on-board mixer, and the standalone mixers available in Ubuntu Studio are for dedicated purposes or affect the onboard soundcard which we won't be using for recording. Note that Ubuntu Studio Controls has been updated for 20.04 and this is where you can set Performance to ensure your system is running the lowest possible latency.

There's even a level meter that might prove useful – or at least look cool – if you have a widescreen monitor with a corner of available desktop space.


Major File Types

Some common file extensions in Linux music software are LADSPA, LV2, DSSI, and SO. The following definition is via https://www.ladspa.org/

  • Linux Audio Developer’s Simple Plugin API, LADSPA, is a standard that allows software audio processors and effects to be plugged into a wide range of audio synthesis and recording packages. For instance, it allows a developer to write a reverb program and bundle it into a LADSPA "plugin library." Ordinary users can then use this reverb within any LADSPA-friendly audio application. Most major audio applications on Linux support LADSPA.

And via http://lv2plug.in/

  • LV2 is the “version 2” of LADSPA. Unlike many popular audio plugin APIs, LV2 is a platform-agnostic Free Software specification with a liberal license.

Via http://dssi.sourceforge.net/

  • DSSI (pronounced "dizzy") is an API for audio processing plugins, particularly useful for software synthesis plugins with user interfaces. DSSI is an open and well-documented specification developed for use in Linux audio applications, although portable to other platforms.

SO files are shared objects, and are not restricted to audio application. They are the equivalent of dll files in Windows.

You'll notice another acronym in these definitions – as any developers out there will know, an API is an Application Programming Interface. Remember, Ubuntu is open source, which means you have access to the code (often written in C or C++). The above open standards mean developers can create their own audio plugins, be they effects or synthesizers or whatever they've dreamed up. The ability to download and modify code has led to an explosion of innovative, colorful plugins. There is some redundancy, but if you look closely, you'll see all of the major schools of synthesizer design have been replicated, and some fascinating hybrids designs as well (see the glossary in section 10).

Tools for DJs

In the Audio Production menu, you'll notice some tools explicitly for the DJ. Internet DJ Console allows you to live stream over the internet. I have not tried this program myself, but it is geared towards podcasting.


I did attempt to use SuperLooper, and once you figure out the labyrinthine interface, it does work as promised. You can create as many overlapping loops as you like. Sessions can be saved and imported to other programs. While intended for live performance, this plugin is not restricted for DJs – if you like overdubbing on the fly, it has great musical applications, and loops in themselves can be quite useful. Some documentation for SuperLooper can be found here: http://essej.net/sooperlooper/.<<BR>> SuperLooper.png

Note: SuperLooper is not included in the Ubuntu repositories and is therefore not officially supported.

TerminatorX is an intriguing program (not bundled with Ubuntu Studio) that simulates record scratching using a digital track and a mouse. The mouse isn't the most comfortable tool for the deft handiwork exhibited by true practitioners, so in the spirit of open source, some fans of this plugin have repurposed old turntables, fitting them with a mouse to reproduce the visual and tactile experience of scratching an actual vinyl LP! https://terminatorx.org/turntables/


UbuntuStudio/AudioHandbook/OverviewInstrumentsEffects (last edited 2020-08-26 23:55:20 by preppert)