The kid synth came about as I sat hunched over a tangled mess of synthesizer wires. My friend Oliver came over, assessed the situation, and said, "You know you have succeeded in making the world's most complicated children's toy." While my initial reaction was to grunt at him, and shoo him away, I later realized that he did have a point. The synthesizer I was working on would make a good kid's toy. So, I took a detour from finishing my big boy synthesizer and embarked on making a child's toy for my one year old nephew.

I designed the synthesizer to have direct feedback, bright colors, and big parts. This makes it easy to understand, easy to use, and fun for children of all ages. Even if the person using it does not quite understand what all of the buttons and knobs are doing, it is fun to just smash buttons, and flick switches and listen to the sound change.

Overall, I am pleased with how this came out. I am hoping that my nephew will enjoy playing with this half as much as I do.

Step 1: Kid-Friendly Design

Making a kid's toy proved to be an interesting design challenge. It not only had to be fun and inviting to a small child, but also virtually indestructible and safe to play with. This meant that I had to minimize the amount of detachable parts, and make it difficult for a child to take apart.

For starters, I decided to use big colorful arcade buttons because of their sturdy construction and inviting appearance. I tested this theory on the Instructables resident toddler and she seemed more than pleased to smash away at the button panel, whether or not the buttons did anything. I next decided to replace the switches, sliders, and potentiometer knobs with home lighting fixture parts. From my experience, I find that small children like to play with light switches and other big buttons. Unfortunately, they were not very colorful and inviting. I solved this problem by adding colored resin to the tops of each of the knobs.

The power switch was also a challenge. I wanted it to be easy enough that my nephew could feasibly use it himself, but difficult enough that he would not get the immediate feedback of turning the synthesizer on and off repeatedly (which would defeat the point of all other switches). I resolved upon a lamp pull switch for this task. Toddler testing thus far has proven successful.

One more thing I had to keep in mind was how to make changing the battery easy enough my sister could do it, but impossible for my nephew. I didn't want him to be able to get into the case and tug at the wiring. I resolved to use a hatch system with two child-proof magnetic latches. In order to get into the inside of the case, you need to know to carefully place a magnet on two specific places on the hatch. This makes the case both seamless, and easily accessible (to those in the know).

The one weak point in the case is the speaker grill. I considered reinforcing this with a metal mesh, but ultimately decided against it. I'm just hopeful he won't try to jab anything long and skinny inside the holes. I did, however,  water seal speaker cone, because - well - you never know.

Beyond that, I simplified the synthesizer circuit that I was working with to only include functionality that gave immediate or near immediate feedback. While some knobs may not work when some of the switches are toggled, my nephew will never be far from making it create some sort of noise, or toggling it back into some sort of highly playable state. This makes it fun enough for a toddler to wail away on, but complex enough that it will still be rewarding as he gets older. This toy is compelling to children of all ages.
It's a great toy! We love to play with it! Thanks Randy!
<p>Just a thought, could you bring your connections to a central PCB, say with an old computer or floppy IDE cable and save a little on space?</p>
<p>That's a good suggestion. That would keep things cleaner.</p>
so... is Instructables going to sell a kit for this? :)
Unlikely. It would cost a bit too much and be very hard for the average person to assemble.
This is awesome!!! You got my vote! I wish I could vote for this ible twice. <br>-BLUEBLOBS2
This is, indeed, the world's most complicated children's toy. <br>-BLUEBLOBS2
Question: besides soldering the 76477 to the breakout board, should one also solder the male header pins to the board? This is not mentioned in the tutorial; a press fit would not seem to assure electrical contact.
Why the yelling? When I get some time I will draw out a diagram. You can get an idea of what the switches do by looking up the 76477 datasheet.
thank you for your answer. sorry about caps. wasn't paying attention when typing. will look up data sheet.
Congratulations on your 200th project! <br /> <br />Your exhaustive yet focused write-up allows me to understand this project just as I would a romance novel at the grocery check out counter. So approachable, so pretty, such nice white balance. <br /> <br />Having heard the synth is person, it's certainly impressive. It beeps and bops with a slight tone of crazy to it, but more of in a way that seems to inspire some kind of artistic genius rather than institutionalization. <br /> <br />I see this as the mozart toy for the 21st century and I think that it's full effects are excitingly not yet known.
Thanks Noah!
Great idea! I built almost exactly the same thing, I think using the very same chip, when I was a kid in the 80s. I was using whatever surplus switches I had, so it wasn't quite as pretty. I used white acrylic for the box--sort of a macbook look back when the beige mac desktop was just coming out. It was endless fun. My only regret was that after I figured out how to make a great end-of-the-world explosion/earthquake sound I nearly gave my mom a heart attack with it.
Very cool. Yes... this thing can make endless amounts of sound. I've been having a ton of fun playing with it.
This is super cool. It definitely looks very kid friendly. Any chance you'll post a video of your nephew playing with it?
If my mom or sister send me one. I actually have not mailed it quite yet... tomorrow perhaps.
I am really impressed with the amount of thought and energy you have put into this. Do you think a person with average electronic skills could build this?
Yes... with enough patience and breadboarding (before trying to build the circuit)
I just had the pleasure recently of a hand's-on experience with this lovely toy. If Randy ever parts with it, his nephew will most certainly enjoy it! If that day comes, I personally will take a picture of him playing with it, send it to Randy to post! Nice job, Randy! <br> <br>Love, The Grandmother. :-)
Working on it.
what is the price of this <br>and would you sell parts <br> <br>i live in England
I didn't keep track of costs, but if I had to guess, the parts alone are probably in the $200 - $300 range. I didn't really have any plans to sell them.
I didn't keep track of costs, but if I had to guess, the parts alone are probably in the $200 - $300 range. I didn't really have any plans to sell them.
This is so awesome! Wish I could build this for my son with cerebral palsy, he would love this. You are very good at explaining but I'm not at all electronically inclined. Maybe I can find something comparable at the store that is not a baby toy as he is a young adult. Any ideas?
The <a href="http://www.teenageengineering.com/products/op-1">Op-1</a> is pretty cool, but it is a bit pricey. I am not sure there is anything that comes readily to mind beyond that. There was a thing with a lot of buttons I saw a while back, but it is not coming readily to mind. I will ask some friends. They will know.
Awsome instructable! I have all of the stuff in my basement somewhere, and am planning on building it soon.
Cool. Let me know how it goes!
While I think it's beyond my abilities with electronics to build this, I would absolutely buy one! I have some nephews and nieces who would love playing with it.
You are not the first person to say this, but between parts and labor, the cost of actually making one is more than most reasonable people would be willing to pay.
I loved this one. And if we put one arduino e one lcd here, what we can get?
Once I get some free time I will answer this question... that was sort of what I was actually doing before I got distracted making this.
Simply brilliant - the concept is great and the colours, brilliant. My granddaughter will love this. Off to the electronics shop I go .....
If you do make one, let me know how it goes!
And I think that would be &quot;heed the warning&quot;, not &quot;head the warning&quot; <br> <br>Nit picking, I know. The 'ible is simply brilliant.
Cool. I wondered why you needed to make it easy to change the &quot;batter&quot;, until I realized that you meant &quot;battery&quot;
Great Scott !!! Too cool w/ the video game arcade system buttons! <br> <br>(ps) almost &quot;just in time&quot; for Moog's birthday!
Yep, his 78th. Did you see the Google doodle for it?<br> <a href="http://www.google.com/doodles/robert-moogs-78th-birthday" rel="nofollow">http://www.google.com/doodles/robert-moogs-78th-birthday</a><br> -BLUEBLOBS2
This seems really cool, but it's a bit too daunting for me. Suggestion, though, maybe make an instructable 'bout electronics and music. I'm confused about how to set up these sound chips and what not.

About This Instructable




Bio: My name is Randy and I founded the Instructables Design Studio. I'm also the author of the books 'Simple Bots,' and '62 Projects to ... More »
More by randofo:Robots ClassBringing it All AroundTelepresence Robot: Shields and Modules
Add instructable to: