Years ago one of Linux's finest audio software developers suggested that I should keep a watchful eye on the Windows/Mac music software scene. I took that suggestion to heart and joined a variety of Windows/Mac-centric lists and forums. I've been able to run many Windows music programs under the Wine emulator, so my participation has gone beyond mere lurking.

Traffic on sites such as Cockos Software and KVRAudio indicates that interest in Linux is on the rise. While I won't claim that the numbers are mighty they are at least persuasive enough for a few manufacturers to test the Linux waters. I have already reviewed the excellent version of Renoise for Linux, and I'm waiting for the Linux release of Garritan's new Aria sampler engine.

Discovery

Now the programmers at discoDSP have recently announced the release of the first commercially-available native Linux VSTi plugin. Discovery is a virtual analog synthesizer with the following major features :

• Two oscillators per layer
• Up to four layers per patch
• Built-in arpeggiator
• Oscillator sync
• Analog FM
• Eight filter types
• Panning modulation
• Stereo delay and gate effects
• MIDI control of patch parameters
• Imports Nord Lead2 system-exclusive (sysex) patch data

Discovery's sound-producing architecture is straightforward subtractive synthesis enriched with a variety of tools for further sonic bending and blending. The screenshot in Figure 1 shows how the GUI is organized to represent the synthesis signal flow. The output from the LFO (low-frequency oscillator) modulates the main audio oscillator stage, and the output from that stage is further modified by the filter and amplifier stages. Extra controls include panning, a gate, and a simple delay line. Performance controls include portamento time, poly/mono modes, and mod wheel assignment.

The Linux version can be used in any host that supports VST/VSTi plugins compiled for Linux. The current list includes Renoise along with the eXT2 and QTractor audio/MIDI sequencers and the JOST multi-format plugin host. Discovery is available only as a plugin, there is no standalone version.

There's no lack of patches for this synth. Discovery comes with 40 banks of sounds, with 128 patches per bank. If nothing there satisfies your ears you can try some of the 3rd-party patch banks listed on the discoDSP Web site. If you're still not satisfied you can import Nord Lead2 sysex data (see the electro-Music archives for Nord sysex files), or you can learn to program the synth yourself.

A Little Testing

I tested Discovery under the Jacklab Audio Distribution (JAD) 1.0, a media-optimized system based on OpenSUSE 10.2, which includes ALSA 1.0.13. I upgraded the system's default version of JACK to version 0.112.0 (managed with the indispensable QJackCtl), and I ran my tests with version 0.4.6 of the JOST host. The system sound hardware includes an M-Audio Delta 66 digital audio interface and an SBLive equipped with an external MIDI adapter. A Casio MIDI keyboard connects to the SBLive. Audio output runs from the Delta 66 to a 100 watt power amp and on into a pair of studio reference monitors.

My basic ALSA system has been augmented with the snd-virmidi module. This handy amenity adds four virtual MIDI ports to the system, all of which are recognized by the ALSA sequencer and are visible in QJackCtl's MIDI connections panel. The virmidi ports enable a multiplicity of possible connections between clients of the ALSA sequencer (an ALSA API feature that provides and manages multiplexed MIDI connectivity).

Speaking of MIDI: Discovery responds to the usual note-on, velocity, and program change MIDI messages. Fifty continuous controllers have been pre-mapped to Discovery's synthesis parameters (the assignments are listed in the PDF manual), and Nord Lead users will be pleased to know that the default assignments are a near-perfect match for the controllers on the Nord synth hardware. User-defined controller mapping is not supported currently.

My keyboard skills are minimal, so I limited my tests to using Discovery in a MIDI sequencing environment (Figure 2). First I composed a short study (Two-minute Mayhem (OGG)) that combined Discovery's palette with the usual Linux softsynth suspects (QSynth, AMS, and LinuxSampler). I limited my patch choices to the default bank, and I used only a single instance of the synth, employing program change messages to vary its sounds. In a second experiment I used five instances of Discovery, thanks to JOST's ability to run in multiple instantiations. Performance was rock steady, with no glitches from either the audio or MIDI streams. My last experiment set up a simple sequence with various controller event streams to program Discovery during the sequence performance. In all these tests the synthesizers were driven by a MIDI sequencer running on the same machine. At ~5 ms latency JACK reported no xruns during these tests.

Documentation

Discovery's documentation includes a comprehensive manual and a variety of demos available from the discoDSP site. The huge collection of patches for the synth includes many great starting points for the creative synthesist, and the discoDSP Discovery forum provides a good channel for learning how other users employ the plugin.

Pricing

Discovery sells for €75/$99. For that amount you get thousands of presets, a sensible and simple GUI, excellent sound quality, and rock-solid stability. If the price still seems a bit steep, consider that it is considerably lower than the cost of a new Nord Lead. :) Anyway, you can try before you buy, just download the demo from the discoDSP site and check it out yourself.

Opinions

Discovery gets high scores for its audio quality and performance stability. Its synthesis architecture is uncomplicated, its user interface encourages hands-on sound design, and the MIDI controller assignments enable dynamic parameter change during sequence playback or live performance. I haven't had the time to test every patch included with the package, but I like what I've heard in Bank 1. Checking out the remaining thirty-nine banks will take a while, and I'm in no hurry. Discovery is now a member of my default crew of Linux softsynths, I'm sure I'll be exploring its capabilities for a long and productive time.

The discoDSP development crew also gets high marks for taking a sensible approach to entering the FOSS world. Discovery itself is closed-source commercial software, but discoDSP has released the source code for their excellent HighLife sampler and placed it under a BSD license. The source package is available on SourceForge, and the sampler has been ported already by Lucio Asnaghi. See his Jucetice Ports News for more information about the Linux version of HighLife.