From HacDC Wiki
The Noisemaker Workshop will teach you how to build noise-making electrical devices from the ground up. We'll be mostly building our own gear, but we'll also borrow a couple tricks from the glitch/bender tradition.
This workshop series involves soldering, (ab)use of digital CMOS chips for analog ends, a smidgen of electronics knowledge (provided), and plenty of noise. You bring the musical sensibility (not required).
Day 1: Getting Oscillating
This class focuses on the 74HC14 logic chip and how it can be used to make a square-wave oscillator. By using a light-dependent resistor in the feedback loop, you can control the pitch by waving your hands around.
Day 2: Modulation
So you've got one oscillator. Great, now build another. Now have the second feed into the first. Fun.
In this class, we get around to Frequency Modulation and gate/sync modulation. We'll also learned about the importance of buffering. LED blinked rhythmically.
Slides, without nearly enough pictures or comments: Media: modulation.pdf
Day 3: Amplification and Filtration
Here we go a little bit analog. Using a 74hc04 chip as a buffer/amplifier, we start to get non-square waves. An amplifier with a capacitor in its feedback loop makes a nice lowpass filter.
(Elliot says: I didn't write out notes for this workshop, and just kind-of winged it. It wasn't stellar. We'll probably need to re-visit some of this later anyway...)
Day 4: Sequencing, Clocking
Using a low-frequency as a clock source, we'll drive a counter which drives a multi-way switch. Point the switch at different resistors = different pitches = 8-step sequencer. Mayhem? Music?
Here's the slides from class: Media: sequencing.pdf
Day 5: Ring Modulation and Sync
This wiki page is still being worked on. What should we do next week?
- Re-visit the LM386 and make ourselves a nice line-level amplifier/speaker combo that'll run on batteries and provide us with a good source of 5v.
- Revisit the 74HC04 and work on filters some more
- Ghetto ring modulation and pulse sync
- Voltage control (?)
- "Handmade Electronic Music: The Art of Hardware Hacking" is a very good dead-tree book on DIY sound hacking. If you've got money to drop on it, it's worth it. You can probably con me into lending you my copy for a week or so. It's a quick read, but you could spend months replicating his projects.
- Some of the sequencing ideas are loosely taken from: fun with sea moss (or, basic digital sound devices).
- For pushing the limits of tolerable noisemaking, The Cacophonator is pretty cool, and uses some of our tricks. It gets a lot of noise out of a single 40106/74hc14 plus the circuit-bender trick of current-starving the chip.
- Ray Wilson's Wacky Sound Generator is another good starter noisemaker.
- The Bug Brand Workshop Oscillator gets a lot of mileage from simple Sync sounds combined and distorted. See his how-to PDF for details.
Note: many of these resources require translating from old 4000-series CMOS into lower-voltage 74hc00 series chips:
- 40106 -> 74hc14 (Inverter with Schmitt trigger)
- 4051 -> 74hc4051 (8-channel switch)
- 4040 -> 74hc4040 (Binary Counter)