The Arcano MIDI NES Chiptune Synthesizer is a minimalistic, microcontroller-based synth designed to emulate the classic chiptune sound of the Nintendo Entertainment System's APU (audio processing unit.) The synthesizer's MIDI input allows musicains create NES-video-game-style chiptune music by simply connecting a MIDI keyboard or other MIDI device.

No programming is required. Each Arcano MIDI NES Chiptune Synthesizer includes a preprogrammed microcontroller; however, each synth also features a 6-pin AVR programming header, allowing programmers to flash the embedded ATmega328 microcontroller with their own custom software. The programming header enables hackers to create their own custom waveforms, envelopes, software low-frequency oscillators, and PCM samples.

Unlike many other microcontroller-based synthesizers which use internal PWM peripherals to generate weak, scratchy, low-quality audio signals, the Arcano MIDI NES Chiptune Synthesizer uses an auxiliary digital-to-analog converter chip to create a clear, high-quality audio signal.

Specifications:

3-note polyphony

1/8'' (3.5mm) jack mono audio output

MIDI input through standard MIDI DIN connector

7-segment LED waveform mode indicator

simple two-button interface

embedded ATmega328 microcontroller

Preset Modes:

Mode 0 - 12.5% duty cycle pulse waveform

Mode 1 - 25% duty cycle pulse waveform

Mode 2 - 50% duty cycle pulse waveform

Mode 3 - 75% duty cycle pulse waveform

Mode 4 - sawtooth waveform

Mode 5 - triangle waveform

Mode 6 - triangle-wave-based drums

Mode 7 - noise-based percussion

Mode 8 - arpeggio, 12.5% duty cycle pulse waveform

Mode 9 - arpeggio, 25% duty cycle pulse waveform

Mode A - arpeggio, 50% duty cycle pulse waveform

Mode b - arpeggio, sawtooth waveform

Mode C - arpeggio, triangle waveform

Mode d - vibrato, 12.5% duty cycle pulse waveform

mode E - vibrato, 50% duty cycle pulse waveform

mode F - vibrato, 75% duty cycle pulse waveform

mode G - vibrato, sawtooth waveform

mode H - vibrato, modulated duty cycle pulse waveform

First PCB Prototype

Latest version featuring lower parts count, higher output rate, and lower output impedance

The hardware design has gone through 3 versions. The latest hardware configuration is capable of producing audio at sampling rates exceeding 44.1 kHz; however, a lower output rate is used in order to faithfully emulate the sound of the Nintendo Entertainment System. The hardware is capable of up to 8-bit quantization. A software bitcrusher is used to achieve the lower bit depths used in the NES. This bit-crushing effect is most evident in the Arcano NES Chiptune Synth's reproduction of the Nintendo Entertainment System's 4-bit triangle wave channel, often used for bass lines and tom-tom drums.

The software has been through 15 versions. All videos were made with the 14th version of the software. The 15th and current version of the software includes additional white-noise-based percussion sounds such as open and closed hi-hats and additional waveform modes including modes created to emulate the detuned reverb effects characteristic of the music from the Mega Man series of NES games.

The creator of the Arcano MIDI NES Chiptune Synth is eager to hear the music created by Kickstarter campaign backers. If the campaign succeeds, please share the music you create with your Arcano NES Chiptune Synth by tweeting a link to @ArcanoSystems.