Vember Audio’s Surge synth could be an ideal choice for an older machine or a tight budget – with deep modulation and loads of wavetables, now free and open source.

And that really means open source: Surge gets a GPL v3 license, which could also make this the basis of other projects.

People are asking for this a lot – “just open source it.” But that can be a lot of work, often prohibitively so. So it’s impressive to see source code dumped on GitHub.

And Surge is a deep synth, even if last updated in 2008. You get an intensive modulation architecture, nearly 200 wavetables, and a bunch of effects (including vocoder and rotary speaker). Plus it’s already 64-bit, so even though it’s a decade old, it’ll play reasonably nicely on newer machines.

Inside the modulation engine.



Synthesis method: Subtractive hybrid
Each patch contain two ‘scenes’ which are separate instances of the entire synthesis engine (except effects) that can be used for layering or split patches.
Quick category-based patch-browser
Future proof, comes as both a 32 & 64-bit VST plugin (Windows PC)
Universal Binary for both VST and AU (Mac)

Factory sounds

1010 patches
183 wavetables


3 oscillators/voice
8 versatile oscillator algorithms: Classic, Sine, Wavetable, Window, FM2, FM3, S/H Noise and Audio-input
The classic oscillator is a morphable pulse/saw/dualsaw oscillator with a sub-oscillator and self-sync.
The FM2/FM3 oscillators consists of a 1 carrier with 2/3 modulators and various options.
Most algorithms (except FM2, FM3, Sine and Audio-input) offer up to 16-voice unison at the oscillator level.
Oscillator FM/ringmodulation
Most oscillator algorithms (except FM2/FM3) are strictly band-limited yet still cover the entire audible spectrum, delivering a clear punchy yet clean sound.
Noise generator with variable spectrum.


Two filter-units with arrangeable in 8 different configurations
Feedback loop (number of variations inside the parenthesis)
Available filter-algorithms: LP12 (3), LP24 (3), LP24L (1-4 poles), HP12 (3), HP24 (3), BP (4), Notch (2), Comb (4), S&H
Filters can self-oscillate (with excitation) and respond amazingly fast to cutoff frequency changes.
Waveshaper (5 shapes)


12 LFO-units available to each voice (6 are running on each voice and 6 are shared for the scene)
DAHDSR envelope generators on every LFO-unit
7 deformable LFO-waveforms + 1 drawable/stepsequencer waveform
LFO1 allows envelope retriggering when used as stepsequencer
Extremely fast and flexible modulation routing. Almost every continuous parameter can be modulated.


8 effect units arranged as 2 inserts/scene, 2 sends and 2 master effects
10 top-quality algorithms: Delay, Reverb, Chorus, Phaser, EQ, Distortion, Conditioner (EQ, stereo-image control & limiter), Rotary speaker, Frequency shifter, Vocoder

Via Synthtopia.