Unnatural Sounds

Barcade

Tue, 28 Nov 2017 20:41:03 +1300

MATERIALS

Pine laminate
Miserable MDF
LED strip light
Lightly tinted perspex for the screen
Clear and opal perspex sandwich for the backlight artwork
PWM controller for backlight brightness control
Intel i5 / 3.2GHz, overclocked to something silly
AMD Radeon HD 8490
Seimitsu PS-14-DN-K buttons and LS-40-01 joysticks
Black spray paint and clear coat
I-PAC arcade control interface
Less blood and fewer tears than the moogCade

My barcade^* uses the wonderful Galactic Barcade designs over at Instructables, except I wanted a bit more beef than a lowly Pi and I still had a thing for 70s synth wooden sides. And so it was.

The moogCade was scrapped for parts. It was far too heavy, stupidly bulky, was comprised of an embarrassing amount of filler and, containing an exposed CRT tube, was a little lethal.

The barcade uses a compromise of a regular 4:3 LCD monitor with software CRT effects for an oddly soothing pastiche of the more deadly, less practical option.

Unlike the moogCade, I took great pains to not be a muppet and rotate the controls.

There isn’t a back, as I couldn’t be bothered. Speakers are free standing, also because I couldn’t be bothered. One day.

The backlight’s brightness is controlled by a quick and dirty PWM circuit. The motherboard happened to have a spare 12v and ground pins, so I used these for powering the circuit and the backlight.

The machine is running Windows 10, Attract Mode with the Flat Blue theme, and a patched version of MAME to remove nag screens and the like.

^*Hillarious and punny name pending.

GLAMOUR SHOT

SHAMEFUL GUTS

The PWM backlight brightness controller is the little ghetto circuit to the right of the motherboard.

moogCade

Sun, 12 Jul 2015 20:52:18 +1200

MATERIALS

CRT tube
RGB SCART TV main board
Intel Core 2 Duo / 3.06GHz
Custom RGB SCART to VGA connector
Ultimarc I-PAC
ATI Radeon video card of some description
Seimitsu PS-14-DN-K buttons and LS-40-01 joysticks
Aluminium sheet
Knobs and switches and stuff
Letraset
Black spray paint and clear coat
MDF, pine, wood stain, blood, tears

moogCade is a MAME-based arcade cabinet with aesthetics crudely inspired by classic Moog synthesizers. Sorry, Bob.

Using a CRT tube with RGB input both allows for the weird and wonderful resolutions and dot timings old arcade games require and provides an authentic visual experience. Who needs fake scanlines when you can risk electrocution and get the real thing?

GroovyMAME is used to generate the correct modelines for the games to keep the CRT, the video card, and myself happy.

The cabinet houses the TV innards as well as a chopped PC running Debian Linux.

Main control panel with mislabeled insert coin button and reversed player two joystick. I must fix that.

The panel is a spray painted aluminium sheet over an MDF base. The joysticks are screwed into the top of the MDF, so the aluminium was chosen to hide the screws and mounting plate.

Letraset is used for the lettering and is protected by a layer of clear coat. As long as you’re careful with your kerning, this is a really effective technique for professional control panel labeling.

Power control panel, with reset hooked up to PC’s ‘on’ button.

Bastard arpeggiator

Sun, 22 Sep 2013 17:21:22 +1200

MATERIALS

4017 IC
4051 IC
40106 IC
Knobs, lights, caps, resistors, etcetera

The bastard arpeggiator is based off the standard quasi-random melody generator circuit, which works by a mixture of multiplexing three oscillators, a decade counter and general misuse of logic chips.

My version differs slightly from the regular circuit in that I’ve added a hand-rolled vactrol hooked up to yet another oscillator in order to give more variety to the output signal.

Huge thanks to the wonderful Mindkits for the components.

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.