Stokin’ the Forge: The Arcano MIDI NES Chiptune Synthesizer

- Posted November 25th, 2015 by

A warm and welcoming November to you fellow ChipWINners! This month, the fires around here are being stoked by something that isn’t an album. A couple months back, a Kickstarter campaign shared to the ChipWIN Facebook group caught my attention, the Arcano. The Arcano was described as a Arduino powered synth kit modeled off of NES sounds. My interest was primarily my own curiosity, but after conversing with the Arcano’s creator, I realized that it would be great to share the project with the whole of the community.

So join me past the fold as I take a look at the Arcano, and the creator of the project sits down to answer more than a few of my questions!

arcano

Right off the bat, the version of the Arcano that I received was a synth in a kit. That means that what I got was the parts and circuit board pictured below. That also means that you’ll need a good soldering iron set, some solder, and a set of helping hands. If you’re completely new to building your electronics from scratch, be aware that this is a slightly involved build. However, don’t let that intimidate you. The build instructions that are provided with the kit are of exceptional quality, and will walk you through every step of the process. There are plenty of resources online to help you get a hang on the art of electronics. My personal favorite being Altman, Nordgren, and Keyzer’s short comic, ‘Soldering is Easy‘.

arcano_parts

Personally, I feel that building one’s tools from scratch in engaging and fosters a greater understanding of one’s craft. I found it pretty easy to put together, and is compatible with standard midi controllers. The Arcano that I purchased came programmed with software version K1.0. This gave me access to 30 different patches, selected using the push buttons on the synth. These patches run the gamut of pulses, triangle and sawtooth waves with a variety of effects.

One final heads up, you will need to buy or scavenge your own power supply for the unit, which will need to be able to supply 7.5 to 9 volts at 650 milliamps. Also, if building the Arcano from scratch isn’t your cup of tea, but you still want one, don’t fret. In the next couple of weeks, it may be possible to buy completed kits through the Arcano Systems website.

In preparing to write this article, I reached out to the creator of the Arcano, who asked to be identified as Tritrium64, to see if he’d be game to answer a few questions about the project. He was generous enough to provide some very detailed answers to the questions I prepared for him, and I’m excited to be able to share them with you, dear readers.


VF: What prompted you to design the Arcano?

Tritium64: I had created a user-programmable retro 16-bit game console which used a PIC microcontroller’s PWM (pulse width modulation) peripheral to generate audio; however, I was not satisfied with the quality of the audio signal, even after I added a low-pass filter and removed the DC bias with a capacitor. Searching for an alternative to PWM, I found an 8-bit DAC (digital-to-analog converter) chip that really improved the sound quality.

Being a musician with an interest in chiptune music, I decided to design a hackable chiptune synthesizer for myself using the same DAC with an AVR microcontroller and a MIDI interface. Originally, I had no intention of selling the synthesizer or creating a Kickstarter campaign.

VF: What was the process you undertook in the development of the Arcano? Specifically, how did you approach the design? What development process did you use, and how did you test it out?

Tritium64: Most of the devices I create begin with a breadboard prototype which is then translated into a printed circuit board design, but I already knew exactly what I wanted in the design of the synth, so I created the printed circuit board layout first and sent the CAD files to a PCB fabricator. When the first PCBs returned from the fabricator, I wrote software for the synth and began experimenting with different waveforms and effects. After creating a few patches that I really liked, I decided to show off the synth to friends.

I got a lot of positive feedback from my friends, and they convinced me to create a Kickstarter campaign to fund a production run for the synthesizer. Before starting the Kickstarter campaign, I wanted to make some changes to the synth to make it simpler, more powerful, and easier to assemble. I started by switching the crystal oscillator configuration from 16 MHz to 20 MHz, which allows for a higher maximum sample output rate. I then removed the potentiometer that controlled the reference voltage for the DAC and configured it for a fixed gain. Removing the low-pass filter reduced the parts count while increasing the audio signal current. I then spent a lot of time improving and testing the software. When I was satisfied with the hardware and software, I launched the Kickstarter campaign.

The synth’s popularity on Kickstarter took me by surprise. I received so many good suggestions and feedback from backers during the Kickstarter campaign that I decided to update the software to include ideas from the Kickstarter community. By the time the Kickstarter campaign was over, I had created 30 preset patches with effects such as vibrato, arpeggio, tremolo, two-channel reverb, and duty-cycle modulation.

VF: What directions, if any, would you want to take the design of the Arcano in the future? Are you thinking of doing anything like custom casing, or expansions? Perhaps a more powerful version, or something that emulates different sound chips?

Tritium64: I have created additional software versions which I may decide to release via replacement microcontrollers; however, I’m waiting on more feedback from users to see how they are using the synth and what direction they want to take the project.

One of the things that some of the users want is to be able to program the synth with the Arduino IDE using just a USB cable, without the need for an AVR-ISP device or FTDI cable; however, this isn’t possible with the existing Arcano synth hardware design. So I have created another 8-bit chiptune synthesizer that I plan to launch through Kickstarter. This new synth is called Obscura; it’s Arduino-compatible and USB-programmable. The software for Obscura is not a port of the Arcano synth software. The Obscura software was written from the ground up and uses wavetable synthesis, while the Arcano synth generates waveforms on the fly through logic statements.

I haven’t designed a case for the Arcano synth yet, but one of the backers has already created a really cool concept mockup for an enclosure for the synth.

ArcanoCase

VF: I remember you being incredibly bullish on community feedback, what’s the best way for members of the community to go about giving it to you? What are some ways you’d really like to see the community push the synthesizer?

Tritium64: Twitter is the best way to give me feedback. (@ArcanoSystems) It’s the only social networking site I use regularly. I hope the Arcano synth users will also send me tweets of the music they create with their synths, because the desire to hear what others create with my synth design was a major part of the impetus for sharing this project with the world. I’d also like for Arcano synth users to create their own custom software and patches, which is why the design includes an AVR programming header.

VF: What is some of the best feedback you’ve received so far?

Tritium64: A user told me the Arcano synth has rekindled his interest in programming and that he’s trying to brush up on his c programming skills, so he can write his own software. That feedback was the most significant for me, because I really like the idea of creating fun and educational devices that inspire learning and creative expression.

VF: Since release, have there been uses of the Arcano that have really stood out to you? Any members of the community that you’d really like to shine a spotlight on?

Tritium64: One backer created a simple demo video of all the preset patches, but that’s the only link I’ve received so far. I’m really eager to hear more from the backers and I hope they will consider sharing the music they create.

VF: Finally, what’s the best way for someone to get their hands on an Arcano now that the Kickstarter is over?

Tritium64: I’m waiting to receive more feedback from Kickstarter backers and to take care of any technical problems they may have before making the synth available for sale to the general public, but I expect the Arcano synth will be available for sale through the Arcano Systems website in about two weeks or so.


I’d like to thank Tritium64 again for the time and effort he put into his thoughtful responses.  Follow the links below if you’d like to check out his projects, his ongoing Kickstarter for the Obscura, or follow him on Twitter. With all that said, I’m closing the forge for this month. For those of you celebrating it, happy Thanksgiving! For those of you who aren’t, go eat a bunch of delicious food with awesome people, because you deserve it!

Now get out there, enjoy life, and make some chip!

VF

Arcano Systems
arcanosystems.com| Obscura Kickstarter | Twitter

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