Image Credit: Surge XT

Surge XT features many synthesis techniques, including a selection of filters, a flexible modulation engine, effects and more.

Originally launched in 2018 as Surge by Claes Johanson, the free synthesizer just got updated from version 1.9 to XT. The interface can be overwhelming, but is comprised of four section: Patch/Global, Scene control, Modulation/Routing and FX. Find the full user manual here. Surge XT is loaded with powerful modern features like MPE and microtuning.


  • Oscillators: 3 oscillators per scene, with 12 versatile oscillator algorithms
  • Filter Block: Two filter units in 8 different configurations. Feedback loop available in 7 of those configurations.
  • Modulation: 12 LFO units available, 6 are per voice and 6 are global for the whole scene. DAHDSR envelope generators on every LFO.
  • Effects: 16 effect units arranged as 4 inserts per scene, 4 sends and 4 master effects. 27 effect algorithms.
The interface of plugin Surge XT
Image Credit: Surge XT

Surge XT is available in 64-bit VST3 and AU formats, compatible with Windows 7 or newer, macOS 10.11 or newer and Linux, with at least 4GB of RAM. Head here to download. No signup required.