CortSynth

Introducing CortSynth, always free, always professional!
If you like CortSynth, please consider making a $20 donation here: https://gofund.me/3baf1e9e8
This will help me to create future free plugins.

CortSynth is a deep hybrid synth, a sampler, and a drum machine — with an organ that spins a Leslie, a piano you can shape, guitars, pads that breathe, basses that hit, and an AI that builds patches from a sentence. The "everything" instrument, in one plugin slot.

It's three instruments:

• Flip between a deep hybrid synth, a sampler, and a drum machine with a playable pad grid — all in one plugin, one window.

Big, mix-ready sound:

• 2× oversampled voices, an analog-voiced ladder filter and a clean modern filter, a lush FDN reverb with shimmer, body resonance, a rotary Leslie, tempo-synced delay, and a transparent glue limiter.

Deep, but fast:

• Dual oscillators with wavetable, wave-terrain, drawbar-organ and resynthesis modes; FM, sync, PWM, unison; two LFOs, a drag-to-wire Modulation Constellation, and four macro knobs that move everything at once.

It makes sounds for you:

• Generate hundreds of presets instantly and offline. Or describe a patch in plain English with the AI Tone Designer. Or drop in audio and let Match Sample resynthesize the real instrument into an editable preset.

It plays like an instrument:

• Real velocity response, touch-sensitive brightness, glide, arpeggiator, strum, humanized tremolo, an on-screen keyboard and mod wheel, and a trance gate.

200+ quality presets:

• Leads, pads, basses, keys, guitars, pianos, organs, strings, brass, bells, atmospheres and textures — plus ready-to-play drum kits.

Sounds & presets:

• Hundreds of patches — and a library that grows.
• CortSynth ships with 200+ handcrafted-quality presets across every category, plus drum kits you can play out of the box. Press one button to generate a whole new pack offline, for free.
• It's also a real sampler. Hit Get Sounds to one-click download free instrument packs — pianos, electric pianos, strings, guitars, woodwinds and more — which install straight into your preset list.
• Disk-streamed sample engine with velocity crossfading.
• SFZ instrument support — bring your own libraries.
• Mapped-key highlighting so you can see what's playable.
• We host nothing questionable — links point to the creators.

A little about the engineering:

• The instruments aren't just samples. Strings and plucks are physically modeled (Karplus-Strong), the piano uses a dispersive stiff-string model with a resonating soundboard and sympathetic strings, and tremolo re-energizes the string the way a real player's pick does.
• Everything is built for clarity: oversampled oscillators and drive to keep harmonics clean, dual filter characters (vintage ladder + transparent modern), a feedback-delay-network reverb with shimmer, a true rotary Leslie, and a glue limiter so presets land loud and mix-ready.
• The audio engine has zero heap allocations on the real-time thread — every buffer, coefficient, and sequence is pre-allocated. It's built for low-latency live performance.
• Physical modeling: strings, dispersive piano, soundboard, resonance.
• 2× oversampling on voices and master drive.
• FDN reverb, rotary Leslie, body resonator, tempo-synced delay.
• Offline preset generation, AI tone design, and sample resynthesis.
• Zero-allocation audio thread — glitch-free under load.

Demo here: {See video at top of page}