Here is the code running on the chip: https://github.com/spookysys/attiny-synth
I took nearly a decade off (shifting into contract app/game dev work, university, and then starting my career did not leave a lot of room for my electronics/robotics hobby) and now the bargain basement price for a batch of 5 "passable" quality boards is <= $10 (and "good" quality for <= $50), surface mount parts suddenly became very accessible and to be honest, for some of the stuff I've played around with, the price savings by using SMT usually pays for the boards. DIPs are getting really expensive. It completely blows my mind.
Now 3D printing is a thing, and it excels at making enclosures for your projects. With a couple hours in CAD, you can have a perfect enclosure on the first try, and they work and look great. Since getting a 3D printer a few years ago, every bare circuit board project in my house has gotten an enclosure, and it's wonderful. You aren't constantly worried about static shocking it, or pulling out some critical wire. You can just use the thing you built like it's a real product.
Other important equipment like PC-connected oscilloscopes and lab power supplies are super cheap now too.
You might have missed an opportunity in the 1990's to make your own boards by drawing with an etch-resist pen. I was making boards like that using money from my paper run.
Maybe we need a new national anthem "Praise God for the rise of China" ;)
I've long ago retired me FeCl acid and DIY copper boards; 3 day shipping from China is just too convenient.
How does the pricing for "extended parts" work? It says $3 per component, but it would seem they mean per component type?
Thinking of doing an FPGA board with them because the concept of soldering an 0.8 mm pitch BGA with hand alignment and a modified toaster oven where a screw up ruins a $50 part is a bit much for me.
If anyone is interested in an incredible piece of music along these lines, please do yourself a favour and check out
TRISTAN PERICH 1-BIT SYMPHONY
(you can skip buying the hardware and find the music on Spotify and similar)
A downvote for this? It nearly blasted my ears while listening this on in-ear headphones after listening to "Chiptunes on the ATtiny4".
EDIT > Are there any similar products to this which are procedurally generated? Is the OP procedurally generated?
Also, not quite procedural either, but the Buddha Machine might be worth having a look: https://en.wikipedia.org/wiki/FM3#Buddha_Machine
If you have any questions, shoot!
I can't imagine how tedious this must have been. It's fascinating what can be archived with determination and this little piece of hardware.
After seeing this heroic SID chip reverse engineering (0), I tried building the filter section using a quad opamp to make the state variable filter. It sounds kinda nice for such a simple circuit.
I've been planning a project of using a micro controller to do the oscillators and then use the PWM outputs to drive the filter control voltages.
But a proper LP/HP/BP resonant filter is almost a musical instrument in itself.
Though hole has... well... holes. It requires tediously placing all your stuff through those holes.
SMD on the other hand, can be solder-pasted and then baked with a $20 skillet + hot air gun to finish off the last bits. The solder has surface tension and naturally "pulls" pieces into place.
SMD is slightly more expensive than a soldering iron: you still need the soldering iron for some bits. And solder paste goes bad over time, and flux to keep stuff clean. You'll also need more expensive PCBs with a solder mask if you want to keep things easiest (but its really not that much more expensive: most costs seem to be shipping costs these days).
So you get your skillet (or toaster oven), a hot air gun, soldering iron, solder wire, solder paste, and finally flux... and you're pretty much set.
Maybe get some "desoldering" pump and "desoldering braid", in case you need to rework some stuff. But the skillet + hot air gun works pretty well.
Work with larger 0805 resistors/capacitors. They look small at first, but you can probably work at that level even without tweezers. More skilled people can work with 0402 and smaller pieces (though that's entering tweezer-only territory)
If 0805 is too small, there are larger pieces available like 1206. But I personally think 0805 sufficiently large for beginners to work with.
EDIT: I'm talking about American codes. 0805 American is equivalent to 2012 European.
Want to try using a flat tip I use for QFPs, but if it's too difficult, I'll get some solder paste and use my hot air station (which I initially bought to de-solder some seriously annoying DIPs (DS1687+ in EDIP) on some old SBCs - the solder just would not come out with solder wick or a pump).
I'm basically imagining tweezers and holding one's breath.
With this stuff at hand, if you're going the beer route, drink it. It'll have two effects: your hands will shake less, and you'll care less how it looks.
Now, tape your board down and set up your magnifier so that you can comfortably look through it as you work. Pick a pad on the footprint of the biggest thing that needs to be soldered (preferably on the side that you hold your iron with). Apply enough solder that there's a noticable bulge. Now, pick up the chip with the tweezers in your non-dominant hand, place it in the right place. While holding the chip in place with the tweezers, melt the solder you placed earlier using your iron until it wicks onto the pin of the chip. Check the opposite corner and make sure that it's lined up, then put a small blob of solder there. Don't worry if you bridge some pins; it's easy enough to fix. Now, solder the rest of the pins. If you're feeling dexterous, you can solder each pin individually, but I don't usually bother. Alternatively (and this is what I usually do), just solder all the pins down with a blob every couple of pins. Most of them won't end up bridged because soldermask repels solder. Once every pin is soldered down, press the wick against the joint with the iron to suck up all the excess solder. Inspect all the joints to make sure you've gotten all the bridges. If there are still some, there are a number of different techniques to get rid of them, but usually just sliding the tip of your iron along the space between the pins will be enough. Worst case, put more solder on and rewick it. Congratulations, you're done!
Repeat for each chip, until you're good at it :-D
(FWIW, I learned from this guide http://goodfet.sourceforge.net/construction/ , which goes into more detail, and also has a nice technique involving taping chips down that works very well)
But author of the article linked right above your comment absolutely can. And wrote a TFA going into great details into how exactly. No stencils, no reflow.