Following up on my voltage starving conversation with Spectral Evolver a few weeks back, today I’m exploring Blood Cells Audio’s “Mangle“, a Eurorack module that’s basically a voltage-starving VCA, where you can send CV to the op-amps (or insufficient CV to the op-amps to voltage starve them). Here, I try a few different program materials, and show some interesting results of modulating voltage starving over time.
You can check out Spectral Evolver’s voltage-starving Moog gear here:
Talking about voltage starving your audio equipment with Will Klingenmeier.
I sat down for a virtual chat with Will, who has been doing some interesting experiments voltage starving his Moog DFAM and Subharmonicon. Voltage starving is when you intentionally deprive a circuit or device of the full voltage it needs to function, simulating a “dying battery”. The sounds you get are probably not what the manufacturer intended, but definitely an aesthetic worth exploring as you look for new sounds.
In this wide-ranging discussion, we talk about circuit-bending, starving stompboxes, and whether or not this is a good idea with your expensive equipment.
0:00 Introduction 0:30 What is “voltage starving”? 1:08 Voltage starving & circuit-bending 1:54 Voltage starving Moog synths 3:46 How to do it 4:33 Is this dangerous to your equipment? 6:07 Thinking about guitar pedals 8:15 Closing thoughts
I’ve just posted a re-edit of my series introducing circuit-bending old toys (cutting the three-video series down into a more reasonably paced single video). 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.
In this series, now edited into a single video, I take you through my process with some toys from the start, including explorations, experiments, and, importantly, failures. I continue work through transforming this Tinkerbell wand, testing out different resistors and switches to see what I might add to increase its glitchy expressive range.
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).
0:00 Intro 0:22 Selecting toys to bend 0:52 Testing with new batteries 1:52 Opening up the Tinkerbell wand 4:42 Opening up the whack-a-mole 7:20 Poking around with test leads 10:40 Recap, equipment 11:11 Examining the components 12:20 Speeding up the clock 14:17 Slowing down the clock 15:19 Varying the clock 18:58 Switches 22:17 The “glitch switch” 24:40 Considering packaging (instrument morphology) 25:19 Tools & equipment 26:15 Updates/Plan 28:32 Installing the “Glitch Switch” 30:48 Installing the Toggle 31:47 Changing the LED 32:47 Installing the Potentiometer 34:17 Adding RCA audio out 35:18 Putting it back together 36:08 Esoteric Etude 38:31 Closing
More circuit-bending and handmade electronic music here:
I circuit bent a Sega Genesis for MIDI-controlled glitch visuals. I can hook it up to a DAW or MIDI sequencer and then glitch out a game in sync with music.
I put this together a few years ago, but had some questions about it, so I cracked open the game system to show how it works. All I’ve done is set up some places to short out the VRAM, where the Genesis stores the sprites for the graphics. Then I added an Arduino to control when it short them out (triggered by MIDI).
Keep in mind that not all Genesis systems are the same, they have different board revisions, so your Genesis might have things in different places.
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 does it mean to “disobey” technology? Expanding on Ernesto Oroza‘s term “technological disobedience”, let’s think about how we can “think beyond the normal capacities of an object, and try to surpass the limitations that it imposes on itself”, working toward a more personal expression through technology using circuit-bending, hacking, creative coding, 3D printing, and glitch art.
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.
Working out how to get the new guts into the old housing
USB MIDI control, 1/4″ output
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.
A few last-minute modifications to the audio-chain
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.
I’ve finally got my workbench set back up following the move out to Connecticut for my new gig at the University of New Haven, and I’ve started to get back to some tinkering.
I had been poking around on eBay for a little while, trying to find an Intellivoice module to build my collection of vintage consumer audio chips. The Intellivoice was an add-on for Mattel’s Intellivion Game Console that strapped on to the side and added a couple of chips allowed a few games to have computerized speech output.
It sounds a little something like this:
Anyway, I found and Intellivoice for about $10 (plus shipping).
The seller, however, neglected to mention that it seems like he had been storing it in a bath of saltwater. I had to drill out a couple of the screws to get it open, as they had rusted beyond recognizability as screws.
After I got the RF shield off, however, it all looked relatively clean. The whole piece isn’t particularly attractive as a collector’s item, but the chips seem to be in good shape.
So, let’s make this thing talk. With a little Arduino magic, I got some words out (see below), and, with a little more tinkering, I should be able to make a MIDI-controlled Intellitalker instrument.
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.
Wires soldered to the underside of the VRAM
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.
Not a huge fan of electrical tape, but what can you do?
Wires run to a set of female headers
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.
Female headers plug into phone keypad
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?
Behold!
The Keypad-Controlled Glitch Genesis!
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).
