Comments on: $50 Gakken Synth Kit Meets MIDI, Ableton Live

By: nick kent

nick kent — Mon, 29 Jun 2009 13:50:04 +0000

Regarding what Video Music said – a Stylophone puts out more or less just square waves, and an Arduino already can make square waves by itself so all you are getting is that little extra something from the old components that you can’t do with just an Arduino… if you manage to scale it. The thing that’s impressive about the SX-150 is it’s undeniably a real analog synth, albeit a simplfied one. As I mentioned, it’s much closer to a “lite” minimal version of Paia Gnome than a stylophone imho.

By: Create Digital Music » Mod the $50 SX-150 for MIDI: Instructions + Code

Create Digital Music » Mod the $50 SX-150 for MIDI: Instructions + Code — Mon, 29 Jun 2009 11:04:53 +0000

[...] A $50 synth that makes neat noises is fun. But a $50 synth that has a proper housing, audio jacks, and can be MIDI controlled — that’s a whole lot better. So readers were wowed last week as we saw the work MrBook did with his Gakken SX-150. [...]

By: Video Music

Video Music — Mon, 29 Jun 2009 06:09:30 +0000

Just recently had a look at my stylophone, and realised that would probably be a very easy hack to add midi control to it. Have a couple of arduino minis laying around that I will experiment with as soon as I got time.

By: nick

nick — Sun, 28 Jun 2009 20:10:02 +0000

Actually the magazine is called Gakken Otona no Kagaku (Gakken Science for Adults) and costs around $35 now. Obviously a chunk of that goes to paying for the synth, but since it only comes with the magazine and is most often sold in bookstores, it’s fair to say it’s similar to other magazines that also have toys or collectables inside. It comes with the disassembled synth in a box with the magazine glued to the box. I’d definitely consider it more an “assembly required” than a real kit since the PCB already soldered in, unlike say a Paia synth kit, (The Gakken SX-150 resembles the PAIA Gnome from the 1970s). The magazine always has some sort of invention in it. My favorite is a phonograph that records onto CDs with a needle and plays them back. They’ve also done a $24 Theremin in an earlier issue. Some years back I bought an $8 science for kids magazine that contained a simple Stylophone type synth, though instead of a speaker you needed to tune in a nearby radio, presumably a Japanese one.

Anyway the Gakken SX-150 must now have the record as the analog synth produced in the largest numbers.

By: Scott Flavin

Scott Flavin — Sun, 28 Jun 2009 15:07:41 +0000

Awesome! I picked one of these up last year and over the past few months it’s been collecting dust on my desk. Hope to change that in the next week :D

By: Darren Landrum

Darren Landrum — Sat, 27 Jun 2009 16:33:21 +0000

Hrm, looking at the data sheet for the DAC you used:

Output swing goes from .010V to Vdd, which can be as high as 5.5V. Let’s go with 5 for now. So, with a 1V/Oct synth, that’s about five octaves you can control. 4096 / 60 (5 oct) = about 68 voltage steps per note. Probably good enough for most applications. And the difference in price between 12-bit DACs and 16-bit ones is staggering.

By: Darren Landrum

Darren Landrum — Sat, 27 Jun 2009 16:16:40 +0000

@mrbook: It seem to me that the 12-bit DAC, with 4096 possible output voltages, might have some tuning issues at the extreme ends of the piano range. 4096 steps / 88 keys = about 46 voltage steps per key, rather than the 100 or so you’d really want for tuning accuracy (not to mention avoiding zipper noise for pitch bends).The output voltage swing of the DAC matters, too, but can also be dealt with in the analog domain.

Of course, the flip-side is that available DACs at 14 or 16 bits are rather expensive and harder to use compared to these cheap and easy 12-bit guys. But then again, my dream is an analog synth with no knobs, using only CV for control, and then using the computer for patching, envelopes, and LFOs.

By: mrbook

mrbook — Sat, 27 Jun 2009 13:46:47 +0000

Hey CDMers, I added post with instructions, schematics and code for this mod. Make sure you let me know if you make something cool with it!

http://mrbook.org/blog/2009/06/27/sx-150-synth-mod-schematics/

Cheers,

By: fran

fran — Sat, 27 Jun 2009 11:44:13 +0000

This is too cool for words. Makes me rethink synths in general. Also, props to Mr. Book for some really nice sequencing/tweaking, making me want to get up and shake my booty a bit. As a firm believer that less is so often far, far more, this video shows why. It’s also really funny to see digital supercomputer wizardry acting as a glorified porter for a $50 noise box.

By: Luke D

Luke D — Sat, 27 Jun 2009 08:28:52 +0000

I’d definitely be interested in schematics and code!