Virtual analog/FM/digital wave modulation synthesizer with FX.


  • 2 x oscillators + noise generator
  • Waveform’s: Saw and Square wave’s with 0-100% harmonics (modulate sin -> saw/square), Pulse wave with pulse width modulation, PM wave (octave), SAW2 (phase + octave), SRQSAW wave
  • OSC’s detune, phase, coarse and mix
  • Cross modulation of frequency (OSC1 -> OSC, and OSC2 back to OSC1), with shape/spectrum control of modulator
  • Multi-mode 12dB filter with blend option (low-band-high)
  • 3 x LFO to pitch, volume, noise, mix, pan, cutoff, q, phase, PM/FM, wave mod1 and mod2. Mod wheel support in LFO1
  • 3 x ENV, MOD env to OSC phase, PM, mod1 and mod2
  • Velocity to volume, pan, cutoff, q, phase, PM, mod1 and mod2.
  • Random (note on) volume, pan, cutoff, q, phase, PM, mod1, mod2, detune and noise
  • Master section with mono and mono/poly legato
  • FX section with chorus, phaser, tempo synced delay, reverb, waveshaper (foldback) and 3 band EQ (lowpass + highpass)
  • 64 preset memory with 2 Factory presets banks included


XT-S1 is a freeware VST 2.4 instrument.

Windows 32/64-bit: downloads (4-feb-24)

Sound demos

Demo 1
Demo 2


Here you can send feedback for XT-S1.