[Kevin] over at Simple DIY ElectroMusic Projects has released a complete DIY modular design for simulating the classic 80s Yamaha TX816 DX/FM modular digital synthesizer. This beast of a synth was used by the cool bands of the 80s as well as TV studios, and ownership of the original machine is an expensive investment. But with the power of modern hackable electronics, and the MiniDexed firmware running bare-metal on a Raspberry Pi getting access to a compatible synth doesn’t have to break the bank.
[Kevin] wanted to emulate the look and feel of the original TX816 aesthetic, developing a custom PCB handling the user interface for four of the eight channels, and a second acting as an interface to the Raspberry Pi using a Pico. Also sitting on this PCB is the GY-PCM5102 I2S DAC, and the MIDI connectors needed to connect to the system controller. Both PCBs, including a PCB-based front panel, were developed with KiCAD. The firmware for the Pico part of the system can be found on the firmware GitHub. The video demo (embedded below) shows off the system running a very 80s-sounding rendition of Holst’s famous ‘Jupiter’ from the planet series, and we all agree it sounds pretty sweet. For a complete rundown of the build, here are the links for the blog series for ease of access: Intro, PCBs, Panel, Build Guide, Mechanical, Pico/TX816 IO code, and finally usage. Phew!
If MiniDexed sounds familiar, that is because we featured another of [Kevin’s] earlier MiniDexed projects a little while ago.
Continue reading “An RPi-Powered Multi-DX7/TX816 Style Synth”
One reason the x86 PC became the dominant game platform in the early 1990s was the availability of affordable sound cards like the AdLib and Sound Blaster. These provided a quantum leap in sound quality compared to the PC speaker’s tinny beeps, thanks to Yamaha’s YM3812 chip, also known as OPL2. [Tyler] has made a detailed study of the various OPL series chips and wrote a comprehensive guide describing their operation.
[Tyler] begins by explaining the theory of FM synthesis. The basic idea is that you generate sine waves of different frequencies, combine them through mixing and modulation, and then adjust their strength over time. This way, a few simple operations on the chip’s nine sound channels can generate an astonishing variety of sounds from clear notes to chaotic noise. He then delves into the details of the YM3812 chip, including its 279 different register settings that enable all these operations.
The final goal of [Tyler]’s research is the design of a YM3812 EuroRack module that fits inside standard modular synthesizers. He’ll go into detail on the board’s design and construction in future blog posts, but he already shows the finished product and demonstrates its features in the video embedded below. It’s a great introduction if you’re new to FM synthesis and want to recreate those magic DOS game sounds.
Of course, you can also just connect the OPL2 chip to your DOS computer, whether through a classic sound card or through a parallel port. The related YM2612 from the Sega Genesis also makes a fine synthesizer.
Continue reading “Recreating The Sounds Of The ’90s With A YM3812 Synthesizer”
We’re used to seeing the Raspberry Pi crop up in a wide range of the projects we show you here, but it’s fair to say that they usually feature some sort of operating system. There’s another way to use a Pi, more akin to using a microcontroller such as the Arduino: by programming it directly, so-called bare-metal programming. MiniDexed is an example, and it copies a classic Yamaha professional synthesiser of the 1980s, by emulating the equivalent of eight of the company’s famous DX7 synthesisers in one unit. It takes almost any Pi, and with the addition of an audio board, a rotary encoder, and an LCD display, makes a ready-to-go unit. Below the break is a video of it in operation.
It’s fair to say that we’re not experts in Raspberry Pi bare metal programming, but it’s worth a diversion into the world of 1980s synthesisers to explore the DX7. This instrument was a staple of popular music throughout the 1980s and was a major commercial success for Yamaha as an affordable FM synthesiser. This was a process patented at Stanford University in the 1970s and subsequently licensed by the company, unlike other synths of the day it generated sound entirely digitally. It’s difficult to overestimate the influence of the DX7 as its sound can be heard everywhere, and it’s not impossible that you own a Yamaha FM synth even today if you have in your possession a sound card.
Curious about the DX7? Master chip-reverse-engineer [Ken Shirriff] exposed its secrets late last year.
Continue reading “Bare Metal Gives This Pi Some Classic Synths”
Those of us who have worked with vintage sound generator chips such as the Yamaha FM synthesizers in recent years have likely run into our own fair share of “fake” or “remarked” chips, sometimes relabeled to appear as a chip different than the die inside the packaging entirely. [David Viens] from Plogue has finally released his findings on the matter after 3 years of research. (Video, embedded below.)
The first thing to determine is in what way are these chips “fake”? Clearly no new YM2612’s were manufactured by Yamaha in 2015, but that doesn’t mean that these are simply unlicensed clones put out by another die factory. [David] explains how these chips are often original specimens sourced from recycled electronic waste from mostly environmentally unsafe operations in China, which are then reconditioned and remarked to be passed as “new” by resellers. Thankfully, as of 2017, he explains that most of these operations are now being shut down and moved into an industrial park where the work can be done in a less polluting manner.
The next thing that [David] dives into is how these remarked chips can be spotted. He explains how to use telltale signs in the IC packaging to identify which chip plant produced them, and visible indications of a chip that has been de-soldered from a board and reconditioned. There are different ways in which the remarking can be done, and sometimes it’s possible to undo the black-top, as it’s called, and reveal the original markings underneath with the simple application of acetone with a cotton swab.
We’ve talked about fake chips and how they can lead to hardware failure here before, but in the case of chips like these which aren’t manufactured anymore, we’re not left with much choice other than FPGA or software reimplementations. Check out [David]’s 40-minute look into these chips after the break.
Continue reading “What To Know When Buying Chips That Haven’t Been Made For Three Decades”
Chiptune is a musical genre built upon the creation of music through the use of chip-based sound synthesizers, found in early game consoles. The Commodore 64’s venerable SID chip and the Game Boy Sound System are the by far the most popular on the scene. However, the Sega Genesis took a different path at the end of the videogame chipmusic era, packing a YM2612 FM synthesis chip to deliver fat basslines and searing solos. [Thea] has always been a fan of these electric 90s sounds, and thus decided to build the Genesynth.
The synth initially allowed only for playback of existing video game scores, but its capability has been expanded as [Thea] took the project from breadboard to protoboard to custom PCBs – with anime artwork, to boot. The synth uses a Teensy 3.5 as the brains, speaking USB to enable the synth to receive MIDI commands from music software. All parameters are exposed over the interface, and [Thea] has several videos showing the Genesynth under control from an Ableton Push.
The sound capabilities of the YM2612 are of an entirely different character to most chiptunes, by virtue of the FM synthesis engine. FM synthesis is a little less intuitive then classical additive synthesis, but we still see it crop up now and then.
FM synthesis is the sound of the 1980s, it’s the sound of shopping malls and Macintosh Plus. It’s the sound of the Motorola DynaTAC, busts of Helios, and the sound of ｖａｐｏｒｗａｖｅ サ閲ユ. The chips most responsible for this sound is the OPL2 and OPL3, tiny little FM synthesizers on a chip, produced by Yamaha, and the core of the AdLib and Sound Blaster sound cards. It’s the chip behind the music in all those great DOS games.
Unfortunately, computers don’t have ISA slots anymore, and cards don’t work in 486 and Pentium-based laptops, the latest hotness for retrocomputing enthusiasts. For his Hackaday Prize entry, [serdef] is bringing the sound of the 80s to the parallel port with the OPL2LPT. It’s a sound card for the parallel port that isn’t just a resistor DAC like the Covox Speech Thing.
The design of the OPL2LPT is pretty much what you would expect; it’s an OPL2 chip, opamp, a 1/8″ jack, and a few passive components. The real trick here is in the driver; by default, every DOS game around expects an Adlib card on port 338h, whereas the parallel post is at 378h. A driver takes care of this in software, but it is possible to patch a game to change every write to an Adlib card to a write to a parallel port.
Already, [serdef]’s parallel port graphics card is a real, working product and has caught the attention of Lazy Game Reviews and the 8-Bit-Guy, you can check out those video reviews below.
Continue reading “Vaporwave For The Parallel Port”
There seems to be a direct correlation between musicians and people who can program. Even programmers who don’t play an instrument often have a profound appreciation of music and so we see quite a few musical projects pop up. [Ihsan Kehribar’s] latest project is a good example. He married an STM32F031 ARM development board, an audio codec, and a simple op amp filter to make a playable MIDI instrument. Of course, it is hard to appreciate a music project from a picture, but if you want to listen to the results, there’s always Soundcloud.
He’d started the project using an 8-bit micro, but ran into some limitations. He switched to an STM32F031, which is a low-end ARM Cortex M0 chip. [Ihsan] mentions that he could have used the DSP instructions built into larger ARM chips, but he wanted to keep the project done on minimal hardware. The audio CODEC chip is from Cirrus Logic (a WM8524), and it produces two output channels at 192 kHz. As an unexpected benefit, the CODEC uses a charge pump to generate a negative voltage (much like a MAX232 does) and [Ihsan] was able to tap that voltage to provide the op-amps in the audio filter with a negative supply rail.
Continue reading “Polyphonic FM Synthesizer Uses ARM”