Sinister Tone Generator
Here’s something I made for the Concerned Citizens exhibition opening this weekend in Wellington. It’s a bass drone synth with two pairs of heterodyning oscillators.
The Sinister Tone Generator was created for a charity auction that raised funds for the Urewera 18. It’s a long story, but in a nutshell: after 9/11 the NZ Police got a bunch of money to set up an anti-terror squad. Problem is that there actually are no terrorists in New Zealand: everyone in this country is too busy having barbecues, smoking dope, going on nature walks, and generally being relaxed to worry about violent overthrow of the status quo. So in order for the anti-terror squad to keep their funding, and to keep the US diplomats happy, the Police contrived to arrest 18 “terror suspects”, most of whom are eco-, animal rights, and indigenous-rights activists: some of whom I know personally to be among the most peaceful and conscientious people on the planet.
In order to make the terror suspects more terrifying the Police then proceeded to leak soundbites to the media: ‘terrorist training camps’, ‘napalm’, ‘assassination plot’, and so on. As the court case has dragged on (five years and counting), all but 2 of the suspects have been acquitted, and more and more facts of the case are coming to light. For instance: the ‘assassination plot’ that the Police were so worried about was purely based on, and I’m not kidding here, a clandestine recording (illegal under NZ law by the way) of 2 drunks saying how they would like to kill George Bush by catapulting a bus onto his head. Terrifying, right?
So the Sinister Tone Generator was my comment on how easy it is for the powers-that-be to make people out to be terrorists: all you need is a creepy soundtrack and some vague accusations.
Here’s what it sounds like with some reverb and filtering added:
If you want to build your own here’s a schematic (updated) and layout (with and without off-board components) that should help you along. I got Ponoko to lasercut the case, I’ll be putting a story up about that soon.
Here’s a gut shot:
And this one gives a better idea of the engraving on the top.
As always, hit me up with any questions.
25 Comments
[...] wrote in to share a new device he built called the “Sinster Tone Generator”. It’s basically a bass drone synthesizer that uses two pairs of heterodyning oscillators to [...]
Looks like an error in the schematic: switch SPST shorts IC1C or IC1D output to ground. The IC won’t last too long with it’s output shorted.
Hey this is really awesome. About how much would all of the components (not including the case) cost to build this from the ground up?
[...] wrote in to share a new device he built called the “Sinster Tone Generator”. It’s basically a bass drone synthesizer that uses two pairs of heterodyning oscillators to [...]
Right you are Kelly, good spotting. That switch should be connected to the other side of R7 and R14. I’ll update it shortly.
Matt if you were to buy the parts retail you could spend about $40 ish. With a good supplier though you could bring that cost way down, probably under $20. Case was $13 FYI.
This is a waaaaaaay cool project! I love the sounds it produces! I’m gonna have to build one of these.
Sounds cool – I’ll have to come check it out on Saturday!
Hi!!
One question… Is the schematic updated?? I don’t know if the switch is now in the right position or not…
Sorry David I’ll fix it up this morning, been distracted. The correct version has the switch running to pins 5 and 9 and V+, as opposed to 6 and 8 and GND like it shows currently.
Ok!Thanks for the update!Amazing stuff!
Wow! Very cool. Can signals be usably (perhaps not important if you’re ripping them apart!) injected into this circuit, such as say a synth or bass?
hey Carl, you can’t inject a signal into this per se, but that’s something I’ll look into in the future because everyone asks that question! As it currently stands the circuit is strictly a signal generator, it doesn’t know anything about the outside world.
Hi again!
The potentiometers are linear or audio (log)?? Wich value of Diodes are you using?1N4148?
I’m ready to buy the materials!
Yep, linear pots and 1N4148 diodes.
Cool project.
I feel like trying this out. The only experience I have is my Midi Mod on my Atari 2600. Hope I can do this one!
On second thoughts David, it won’t make a huge difference but you’d probably get a better response out of log pots for the pitch control.
[...] a schematic, if you’re interested. You can hear it in this demo, where I’ve used the sinister tone generator as a source. There’s plenty more work to do on it yet but it’s pretty fun just as [...]
I’ve added another center-off SPDT switch to allow you to connect pin 1 or 3 to V+ if you want to switch out one oscillator from the voice. And duplicated it on pins 11 and 13 for the other voice.
Hey
I want to build one of these.
What board did you use for this and where did ya get it from? Also is the schematic all good?
Finally. What supplier would you recommend?
Thank you!
Hey Liam I just use cheap nasty protoboards from China, pad-per-hole type. All my parts are supplied by jaycar.co.nz but there are plenty of better suppliers online that will do you fine, the parts are all very common components. The schematic is sweet.
Hi!
This is a great project! One question: What value is the electrolytic capacitor? Its the only value missing from your excellent schematic.
Also thank you very much for sharing your work!
Ups! Just realized the cap. is for the LED only. Just ignore my question
Hi again!
I built the synth and is sounds fantastic! Only a quick question about the circuit:
What is the point of IC1C and IC1D? Is is some form of amplification? Wouldnt discarding them make the output sound smoother?
Good question Knute. It’s been so long now I’ve forgotten. I think you are right that it is smoother without them, I think I made one version of the circuit with a switch that allows you to bring the last gate in or out.
I’d love to hear a sample of your machine!
that is so great to hear! Any recordings or photos? So exciting