OPx-4: FM Synth Plugin by AIR Music Technology Free Download

The synth engine combines four operators with a 32-slot FM modulation matrix, so you can route many modulation sources to the parameters you want to move. Each operator offers its own controls for pulse width, formant, FM filtering and FM shaping, along with ADSR and oscillator envelope settings.

The instrument can produce deep, evolving sounds with a strong attack, morphing timbres or filter movement. It can also produce digital tones such as classic electric piano sounds, 80s-style FM sounds and unusual FM sound effects.

Eight macro knobs are designed for controlling FM effects from one place, which helps when you want to make broad changes quickly. The built-in effects section covers compression, EQ, delay, reverb and lo-fi processing, so you can stylize a sound without adding separate plugins.

Multiple preset banks give you a starting point if you prefer to begin from existing FM sounds and then edit them.