Free Chiptune Synth

YMCK has released the Magical FDS Plug, a software synthesizer plug-in that reproduces the sound of the Disk System (FDS) sound chip. It can be used within Mac / Windows host applications that support Audio Units and VST3. They say that it has an intuitive UI that tames the complexities of the FDS sound engine with logical waveform editing via additive synthesis, waveform shaping and more...

Here's more details direct from developer Takeshi Yokemura of YMCK...

The FDS sound chip features a unique architecture in which a 64-sample waveform memory (carrier) is modulated by a separate 32-step instruction sequence (modulator). Despite its steep learning curve, Magical FDS Plug preserves the full flexibility of the original hardware while providing a logical interface for building waveforms -- through additive synthesis, presets, and more.

Features:

• Carrier + Modulator -- two independent signal paths. Design the audible waveform (carrier) and its modulation sequence (modulator) separately.
• Logical waveform editing to take the guesswork out of FDS sound design:
  •     Additive Synthesis -- Drawbar-style, like a tonewheel organ. Mix harmonics with 8 sliders.
  •     Preset Waveforms -- Start from triangle, sawtooth, or sine wave, then reshape the tone via compression and expansion.
  •     Pulse Waveform -- Shape the waveform by adjusting the pulse width (1–63) of a square wave.
  •     Freehand Drawing -- Draw a 64-point waveform directly using sliders.
• Modulator: 6 presets + Custom -- Triangle, sawtooth, sine, square, ramp up, ramp down. In Custom mode, enter a 32-step opcode sequence (32 digits, 0–7) as text.
• Modulation rate modes -- Three modes: LFO (slow, cyclic modulation), FM (timbral modulation), and OFF.
• ADSR envelopes for both carrier and modulator -- Shape the volume and modulation over time, with the same workflow as Magical 8bit Plug 2.
• Hardware-accurate output filter -- A ~2 kHz low-pass filter modeled on the original hardware, switchable on/off (default: on).
• Preset save / load -- Save and load all parameters as an XML file.

Pricing and Availability:
Free

More information:

• Magical FDS Plug