Lo Fi – Page 3 – Simon Hutchinson

Over the break, I took some time to put together an arduino-driven synth from this “instructable” by Brian Peters.

Yeah, inside the radio case

This is a synthesizer made from four SN76489 chips. These chips appeared as a cheap audio solution in a number of old computers and game consoles, including the ColecoVision, NeoGeo Pocket, Sega Genesis (although the Genesis had another chip capable of FM Synthesis).

Because these chips are cheap, this ends up being the cheapest synth on my rack:

$19.00 – Teensy 2.0 Board
$4.50 – 4x SN76489AN Chips (includes shipping)
$1.30 – 1.8432 MHz Oscillator
$0.10 – 4x 75k Resistors
$0.10 (or so) – 4x 10µF Capacitors
$5.00 – 4x 1/4″ Audio Jacks (these were way too expensive on Sparkfun)
$5.00 – Breadboard

$45.00 – Total (give or take)

So, it’s been about 15 years since I bought it, but I think that’s even cheaper than my Alesis Nanobass (appears in the background of these photos).

Why did I put it inside and old radio? Because that was what I found a Goodwill for $2 that was an appropriate size.

The aptly named Arduino "Teensy" — The aptly named Arduino “Teensy”

Teensy, SN76489 chips, and quartz clock ready for wiring

So what does it sound like? Here’s a quick and dirty demo:

Always looking for an excuse to open something up

For my latest “chiptune” project, I’ve put in some RCA jacks on my Super Game Boy.

Of course the Super Nintendo already has the possibility of a component out (via RCA jacks), but, since the Super Game Boy basically contains all the circuitry of the Game Boy, this mod bypasses the Super Nintendo altogether.

If you’re interested in trying this yourself, check out this instructable for step-by-step instructions.

So… Does it sound better? I don’t really know, and I don’t really have the time to set up a comparison, but this mod sure makes it easier to get sound to my mixer.

Here are a couple quick recordings of games I had lying around:

Battletoads

[audio:http://www.simonhutchinson.com/BattleToads.mp3]

Ninja Gaiden

[audio:http://www.simonhutchinson.com/NinjaGaiden.mp3]

The thing I have to be careful of, though, is that the clock speed of the Super Game Boy (4.295 MHz) is 2.4% faster than the Game Boy (4.194 MHz). A minor change, certainly, but a significant one if I’m trying to keep my music in tune between different devices, and I’m switching between the SNES and a Game Boy.

…like the time I brought my NOPera to Germany, forgetting that Europeans don’t tune to A440.

Tag: Lo Fi

SN76489 Chip-Based Synthesizer

RCA Output on a Super Game Boy