Unnatural Sounds

Eight-step sequencer

Fri, 18 May 2012 08:29:00 +1200

December 2011

MATERIALS

40106 oscillator
4017 decade counter for ADC
4040 ripple counter for ADC
LM311 voltage comparator for ADC
4046 VCO
Bunch’o’LEDs and slider pots

(Or, “why bread-boarding is a good idea”)

This sequencer uses a poor-man’s resistor ladder combined with a comparator to serve as a note quantiser. Other than that, it’s just a basic eight-step sequencer that spits out a nasty square wave.

It mostly works, although:

Resistor ladder based ADCs are fun to play with but a bit twitchy and a bit of a pain. Plus, most of my components and time spent was to build this - I’d have been better off using a dedicated analog to digital chip.
Despite being too impatient for breadboarding much of the time, the associated photo with this post indicates why it’s probably not a silly idea with any non-trivial circuit…

The Doof Doof Machine

Mon, 14 May 2012 08:12:00 +1200

MATERIALS

Mini Space Rocker circuit
40106 oscillator
CV in jack
Audio out jack
Switches, knobs, LED

The Doof Doof machine comprises of one of Eric Archer’s delightful Mini Space Rockers, combined with a trusty oscillator and a bunch of knobs in order to make it an almost-convincing bass drum machine.

The unit is hooked up with a tempo adjustment pot and a doof speed divider in the form of a rotary switch. This provides the ability to have doofs on every beat, every second beat, fourth beat, etc.

There’s also a switch to toggle between regular and divider modes and a supplementary button to trigger regular mode. This allows for momentary doof freak-out, to keep things corny.

The Doof Doof machine also features a gate input and a gate input selector switch. The gate input allows the unit to be driven from an external sequencer.

Florian

Sun, 25 Mar 2012 00:00:00 +1300

MARCH 2012

MATERIALS

Speakjet speech synthesis chip
Teensy development board
Bunch‘o’components

Florian is a prototype software + hardware text-to-speech solution. It provides a command-line tool to take program arguments as input, uses the CMU pronouncing dictionary to first convert text to phonemes, then to Speakjet phoneme codes.

It then uses the built-in Teensy UART functionality to stream this to the Teensy over USB, which contains a simple program to interact with the Speakjet and provide buffer management.

The audio output is then run through a passive two pole low-pass filter and an LM386-based amplifier.

CODE

Both the client side code and embedded code may be downloaded here. My c/c++ is a bit rusty, but it should be useful as example code or as as starting point for your own Teensy or Speakjet project.

Thorn Pseudoscope

Sat, 05 Nov 2011 08:17:00 +1300

OCTOBER 2011

MATERIALS

Old television
Audio jack
Pot for brightness control

There’s not much to this guy – it’s using the old technique of severing both the horizontal and vertical deflector cables from the television, connecting the horizontal wires to the vertical connection, and connecting the vertical wires to the audio jack.

As an oscilloscope, it’s pretty useless, but it looks good!

Teenage Mutant Ninja Cookie Monster

Sat, 01 Oct 2011 00:00:00 +1300

OCTOBER 2011

MATERIALS

Cookie monster toy
2 × pots
40106 oscillator
Audio output
2 × buttons
Indicator LED

The Teenage Mutant Ninja Cookie Monster was my first circuit-bent toy. It features the speech chip out of a Cookie Monster toy with the timing resistor replaced by a pot, allowing for variable pitch output. The toy’s momentary button is hooked up to both an external button and an oscillator, with a pot to control oscillation speed.

The oscillator mode allows for stuttered output and, in combination with the pitch control, produces a curiously interesting array of sounds.

The Seductobot Jacob's Ladder

Tue, 01 Feb 2011 00:00:00 +1300

FEBRUARY 2011

MATERIALS

10kV neon sign transformer
1930s Rimu cabinet
Metal pudding basins
High voltage glass bushings
Restaurant wine glass holders
Key switch

The Seductobot Jacob’s Ladder was made for a local show, The Seductobot, where it featured in a stereotypical mad scientist’s laboratory. Many thanks to Frampton Signs for the equipment and assistance.

If you’re making one of these bad boys, I’d highly recommend using for electrodes the rack things that restaurants use for storing glasses upside-down. They’re not only sturdy and cheap, but they conveniently have a kink in them, which is perfect for establishing the V shape.

I’d also recommend using slightly more then 10kV, because without an additional central so-called ‘Gabriel’ electrode it’s a bit fiddly to get the spark gap just so.

This unit is currently out-of-action due to an on-set incident. Word for the wise – it’s better to secure electrodes to something non-fragile and sturdy (i.e., the enclosure) rather than to glass bushings.

Overlord Ducky

Thu, 02 Dec 2010 00:00:00 +1300

DECEMBER 2010

MATERIALS

Rubber duck
3V red lasers
USB cable
Toggle switch
Black and bronze paint

Overlord Ducky is a trivial circuit, using USB voltage to power two red lasers and a toggle on/off switch to facilitate workplace harmony. It’s inspiration was taken from this Instructable, however involves less belly-slashing (hint: large eye sockets are convenient for component insertion), and more Overlord.

The lasers were inserted into metal bushings for extra ducky dominance, and the ducky itself painted as a somewhat embarrassed nod towards the steampunk aesthetic.

Two versions were made, one with laser eyes and one with child-safe LED eyes. Both have been sold.