Watch me dissect and old phone and repurpose its carbon microphone.
Constructing a lo-fi microphone from an old telephone’s carbon microphone, and seeing what other parts we can make some sounds with.
I got this old phone at Goodwill for a couple bucks, interested in seeing if it had a carbon microphone that I could salvage. It turns out getting that microphone out was a breeze. Then I started seeing what other parts might be interesting–the keypad, the chip that makes DTMF tones. Finally, I put together the circuit for the carbon microphone, and got it back in the handset, adding a new specialty carbon microphone to my mic locker (such as it is).
I’ve put together a three-part series on getting started with circuit-bending, from the initial testing and opening up toys to completed alien instrument.
(Part 3 coming next week)
Circuit-bending is the creative customization of consumer electronics with the goal of inventing new unique devices for sound-making, visuals, or other expressive goals. I’m a composer and sound-designer, not an electrical engineer, so my goal is to find fun sounds that I can use in creative ways (rather than any kind of serious circuit design).
For more of my creative electronics projects, check out here:
What is “Lo-Fi Music”? What are the expressive goals of making stuff sound bad? Why are there so many “Lo-Fi beats to study to” videos on this site? Why do they all have 1990’s anime images and video?
In this video I talk about some of the possibilities of how “LoFi” music responds to the hyperreality and commercialism of “HiFi” (literally “high-fidelity”), and what our contemporary interest in LoFi might mean to some artists.
Since last time, I added MIDI control and transferred things to a smaller circuit board (and Arduino) in order to fit everything back in the original case.
So what does this little synth do? It takes MIDI notes (from a keyboard or DAW), and uses them to trigger the sounds built in to the Intellivoice chip, which, as it turns out, consist of mostly numbers.
Check it out:
I might look into a few more tweaks. Currently, each word will always play to the end, even if another word is performed before it’s finished. I’m not sure if this is a property of the Intellivoice chip, or something I could fix in my Arduino program.
Why pursue a project like this one?
Games and gaming hardware are mass-produced devices with planned obsolescence and few serviceable parts. By “hacking” and customizing gaming hardware we regain personal ownership of these devices, and we can turn obsolete equipment into performable, expressive instruments.
An earlier version of this synth actually appears in the electronics of my new commissioned work, Hirazumi (more about the piece here and here), and I think the hacked Intellivoice fits perfectly into the post-digital, cyberpunk aesthetic.
Hoping to “veg out” a bit upon returning from holiday travel, I put on one of the new Ghost in the Shell animated films.
It’s always funny how ideas connect, but, earlier in the day, I had been chatting with my friend and colleague, composer Aaron Rosenberg, about my current composition project, Hiraizumi, and, in talking about the piece, he had referred to the electronic parts as “sci-fi moments” (fondly, of course).
I previously wrote about how I was crafting the electronics to evoke distortions in digitally-mediated memory, and, revisiting Shirou Masamune’s world of Ghost in the Shell, primed to think about sci-fi music, I realized that my wind ensemble piece falls into the cyberpunk genre.
In Ghost in the Shell, memory (and its fallibility) is a recurring theme. People with cybernetic brains are able to directly access the internet, but this connection opens people up to having their minds and memories directly changed (and possibly hacked), and interacting with others on the web breaks down the border between self and others.
If one’s self is defined by memories and experiences, inaccurate memories (or memories curated by Facebook), might reduce the sense of individuality. This loss of individuality and the dehumanizing effects of technology are common cyberpunk themes.
As the protagonist, Kusanagi, says:
There are countless ingredients that make up the human body and mind, like all the components that make up me as an individual with my own personality. Sure I have a face and voice to distinguish myself from others, but my thoughts and memories are unique only to me, and I carry a sense of my own destiny. Each of those things are just a small part of it. I collect information to use in my own way. All of that blends to create a mixture that forms me and gives rise to my conscience. I feel confined, only free to expand myself within boundaries.
Hiraizumi’s cyberpunk elements seemed even clearer, when, looking back on my choices of sound design in the electronics, I discovered moments that seemed inspired by sounds from Ghost in the Shell and Vangelis’s score to Blade Runner, another cyberpunk film that questions ideas of self and identity.
That all said, I wasn’t thinking about Ghost in the Shell when I started work on Hiraizumi, but I am a fan of Japanese cyberpunk, and these things are all rattling around in my head
Created without conscious intent, these cyberpunk themes are a byproduct of the expressive goals of the piece, and I look forward to where the music will take me as I finish my journey to the double bar.
(As an end note, I should also mention that it’s no surprise that one of my old musical heroes, Cornelius, did the soundtrack for the new Ghost in the Shell series.)
Hiraizumi’s collection of temples were a quick trip from where I lived in Japan for many years, and I wanted to write a piece drawing from my memories of the site, centering on my relationship with the location as an “outsider.”
As I write the piece, it has been evolving from a simple homage to the temples into a larger exploration of memory and how the past is mediated by the present. My nostalgia about my time in Japan (and that time in my life) flavors my memory of Hiraizumi, and, in addition, the centuries of history embodied by the site is mediated by our experience as citizens of the modern world (who, for example, might go home from the site to our digital lives).
Expressing these thoughts in prose feels a bit clumsy, so that seems good reason to unpack these ideas using the expressive possibilities of art and music.
Here’s a teaser of the electronics, a kagura-suzu brought into the post-modern world of digital distortion:
Back to the Sega Genesis Mods! If you’re catching up, check out Part 1 and Part 2.
Where we left off, I had found my glitch points, and I was going to get digging in to some kind of button control before moving on to MIDI control.
Here are the pins of the VRAM with some wires from some selected spots. Purists might fault me for not running off of all of the 44 available points (48 minus the two VCCs and two grounds), but I didn’t have that many buttons anyway.
After taping things down, I ran the wires to a set of headers. The reason for using headers is to keep the ability to remove the top of the Genesis if I want to get back inside for any reason.
I had a phone keyboard kicking around, and I figured this would be a simple alternative to setting up a matrix of buttons. How this works, then, is any one button connects two points (which two points hardly matters), and if one holds down multiple buttons at the same time, several data points start cross-talking with different visual results
Are you ready for this?
Here’s a video of it in action:
Now, of course, while I’m stoked about my new toy, this instrument is not yet what I set out to do (and what the title of these posts proclaims).
MIDI-Control, though is just a quick hop away. Next time, I’m going to get a new Teensy, install it in the Genesis, and program it to control the connections via USB MIDI control (likely with some simple transistor work).
Continuing my Sega Genesis Project, now that I’ve got the video in a form my TV can understand, time to start messing with things.
Repeating my disclaimer: Messing with things plugged into an outlet is dangerous! I’m only doing this because the Genesis has an adapter that converts the voltage to 10V DC long before the power gets anywhere near the board.
When in doubt, only circuit-bend things that are battery powered. Think of how embarrassing it would be for your parents (or wife and son) to explain that you died trying to get glitchy video from a game system.
Anyway, that said, time to start poking around a bit.
These are the Video RAM chips whose connections I’m going to bridge. They have 24 connectors apiece, and one on each is the power, one on each is the ground, everything else (I believe) is data. So all we’re going to do is send some of that data to the wrong places.
I’m going to poke around the bottom here, because the contacts are more accessible.
(By the way, the resistor and capacitor you see here are not my work, just an afterthought by the designers of the PCB.)
That looks pretty glitchy to me.
I’ve found a few points that give a variety of effects (relatively). The next step (next time) is going to be installing a way to control these. I’ve decided I’m going to start with a push-button system before moving on to the MIDI control for two reasons:
1.) Moving in small steps seems wise.
2.) I’ve used up this month’s tinkering budget, and I’m going to need a Teensy to get the MIDI working.
The Genesis uses a Yamaha FM synthesis chip for sound, which might be interesting to dig into at some point, but my main goal in cracking this machine open was to try some video circuit-bending: apparently pretty easy to do, bridging the legs of the VRAM.
First, though, I didn’t have the little box that I need to hook the Genesis up to the TV, so, instead of trying to track one down, I decided to install component video RCA outs.
So, away we go!
After some poking around on the internet, I found that there are lots of different revisions to the Genesis circuit board, and this, the VA7, is apparently the least desirable. The audio is actually synthesized on a different chip, but Sega didn’t account for the difference in output volume of the new chip in the internal amplifier, so the sound has all kinds of digital distortion.
Well, that just means if I fry this thing, I won’t feel so bad.
Quick disclaimer: Messing with things plugged into an outlet is dangerous! I’m only doing this because the Genesis has an adapter that converts the voltage to 10V DC long before the power gets anywhere near the board.
When in doubt, only circuit-bend things that are battery powered. Think of how embarrassing it would be for your parents to explain that you died trying to get glitchy video from a game system.
Hearing the complaints about the sound on the VA7, I did a quick adjustment by adding a resistor to pull things down a bit, and a capacitor to roll off some highs (I think that’s how it works. Someone please correct me if I’m wrong).
I’ve since found someone designed a Crystal Clear Audio Mod, which seems a lot more involved (and likely better) than my “quick and dirty” solution.
Success! Next step: start glitching that video feed.
Check back for Part 2 soon.
“Inspiration does exist, but it must find you working.” – Pablo Picasso