Show HN: I built a synth for my daughter
bitsnpieces.dev555 points by random_moonwalk 5 days ago
555 points by random_moonwalk 5 days ago
This is such a good idea!
Kids music toys are often just purely toys tap a button, make a sound... But the skill ceiling could be so much higher, offering the ability to learn and express themselves more. Awesome work.
Thanks for all the kind words and feedback. There are some comments expressing interest in supporting a Kickstarter etc. If you're interested in receiving updates you can leave your email here:
Thanks again - this was a bit of a surprise!
Looks amazing! Reminds me of a funny reddit thread about a man who built a fiber optic star ceiling for his daughter. The top comment was "First child?". :)
https://www.reddit.com/r/DIY/comments/8g8pce/fiberoptic_star...
And then the things you do to redeem your guilt for the second child is a whole interesting area.
Don't assume: Could be an only child, or the spouse is stay-at-home, or the author has family wealth and doesn't need a full time job.
What I love about this is how physical it is. So yeah, there's some board running DSP. but the design is amazing. It really relates to some recent posts also in HN about many objects loosing their physical UX. from an age of having buttons and tactical interfaces, everything became more touch based / app based which indeed cut price and allows easier updating. but also lacks some romance which is exactly what this device shows.
> A 3D-printed enclosure is fine for a prototype, but a real product likely needs injection-molded parts, which require expensive tooling.
For kid-friendly toys, yes. But for older users not necessarily:
How are these, are they worth the money? I have seen these before, but thought they might be crappy "jokes". However, if they are decent, I would love to play around with them.
[context: I have eBay’d a couple of Pocket Operators because I was curious and the price was low enough I knew I could at least break even reselling on Reverb even after fees and shipping…This is how I rationalize my gas.]
Maybe buy one and if it is not for you be ok reselling it at a loss…framing it as renting an instrument helps me.
The Pocket Operators are musical and inexpensive for musical instruments.
Like any musical instrument practice hours are how you get amazing results and whether the instrument gels with you is the biggest influence of whether you put in the hours.
For me, the Pocket Operators haven’t gelled…I just don’t enjoy them enough to put in the time. But other people find them great and I can see why (not-for-me != bad).
The pocket operators have kind of 'grown up' and now they are doing a larger format thingie that is kinda like a pocket operator: https://teenage.engineering/products/ep
I especially like the bardcore one: https://teenage.engineering/products/ep-1320
I have a friend that writes lots of music on the PO-33. They are fun, definitely toyish, but you can get good results:
https://www.youtube.com/watch?v=TBo8Rd7HxdU <- a friend that creates a lot of music on small "affordable" pieces of gear.
They -are- decent modular chunks. They have a bit of opinion pushing you in certain directions as far as sound goes.
Each one does a pretty limited set of things and combining them can be annoying.
But you get a lot for the money you spend on them.
combining them can be annoying
The strong design opinions about how the Pocket Operators interact with other musical gear are a big part of why I haven’t had high enthusiasm for using the small PO’s when I’ve had small PO’s.
For me, Volca’s are a similar ecosystem but to a lesser extent…maybe because the Monotrons sit lower in Korg’s product portfolio while the PO’s are rock bottom of TE’s product line.
It’s pretty capable hardware, but in my personal opinion the UI sucks. It falls into the category of “why did you make this hard on purpose” and I resent it.
Wood is also pretty child friendly.
But neither injection molding nor carpentry will protect a synth from a child dunking it in a puddle of water.
I have two of those. They are great additions to my drawers.
One has a silicon case and is nicer to use though.
You say "they are great additions to my drawers". Is that because they suck, or is it that you don't have the time to enjoy them? (which I totally understand) I have seen these before and didn't know if they were worth the money. What is your opinion on them?
On one hand, $100 will buy a lot of hamburger. On the other hand, it's relatively low for a musical instrument and pretty easy to justify when if you suffer from gas.
I am only speaking for myself, but I have a drawer of small musical electronics that I use occasionally. I bought them because I was curious.. I keep them because they are musical and not worth selling.
I have the PO-12 (drum machine), and the PO-33 (sampler). They are somewhat limited but that can a good creativity booster.
I don’t use them often because I’m not a great musician. I think they were worth the money, for sure.
Amazing the things we do for our little ones. I built a toddler-friendly keyboard for my son. He's still playing some form of piano 6 years later, no longer with his fists or feet.
It's not kid friendly, but in case anybody's interested I just wrote up how I made a simple "hardware" synth by bodging together a Raspberry Pi Pico 2 and I2S audio module, total cost around £10 on Amazon UK.
The hardware's very cheap and easy. The "default" synthesis is pretty simple but also pretty hackable (in Rust) if you want to customize it.
Great finish. I was busy designing and soldering the prototype synthesizer during the summer, but I had to put it on hold because my baby was born in September.
I had the same problem back then: injection molding is quite expensive to start. But you could consider a more creative approach: using a PCB directly as the panel, such as a TE's Pocket Operator. Korg also has this solution for some educational products. Alternatively, you could use 3D printing; there are many inexpensive services in China. CNC doesn't have the mold-making issue, but it's more expensive and doesn't seem suitable for children.
Another interesting point: after my child was born, I didn't have much time for my sound work. But recently, I was surprised to find that I spend most of my time playing white noise on Glicol (http://glicol.org/) and it works great for my kid.
``` o: noise 42 >> lpf ~mod 1 >> mul ~mod3
~mod: sin ~mod2 >> mul 200 >> add 1000
~mod2: sin 0.1 >> mul 0.04 >> add 0.1
~mod3: sin 0.04 >> mul 0.3 >> add 0.8 ```
Good luck with kickstarter!
Would love something like this for my daughter, but with a max volume option she can't tamper with LOL
I've been learning CAD, 3d printing, PCB design and brushing up on my embedded programming... all with the goal of being able to build toys for/with my son. It's incredible how accessible it is in todays world, made possible by these advancements:
- incredibly powerful and cheap microprocessors (esp-32) - Fast, high precision desktop 3d printers - Affordable small batch PCB manufacturing - LLM's to advise on circuit design and help with embedded programming
Would you have any interest selling a non-comm license to the PCB, f3d files and source code? My 1.5yo son would absolutely love this!
If I have zero experience designing PCBs but wanted to do a similarly (non)-complex one, how much of a tall order would that be? In my completely made-up mental model, I'm guessing I just take the parts I've already breadboarded, look them up in some sidebar, and drag and drop them around, snapping to nice clean spacing, and then connect all the various pins together and have it automatically organize things? We're not going for perfect here. Just "Baby's first PCB" that at least works.
And then when I have one designed, how much would it cost to get made and sent to me if I was okay if it took a month?
But most importantly: how do I build personal confidence that I'm not shipping a potato off to be printed? Is there a community I could ask for a review from?
For another data point: last week I ordered my first PCBs from JLCBCB. 2 fully assembled (parts already soldered) and 3 bare. $40 for the boards themselves, $40 for shipping, and $20 for US Tariffs, for total $100. Should take a week to arrive, shipping's cheaper if your willing to wait a month.
Re help: I asked for some help on libera ##electronics. I think there are larger communities on reddit that would also take a pass over designs.
My impression is that for straightforward circuits (not very high frequency or high power) you can get away with almost anything as far as layout goes. You punch in some generous setting for spacing of traces etc in the CAD software and it does some basic validation. (Are all the parts connected, not too close?).
I used KiCAD. It works well, though for assembly EasyEDA is probably lower friction. I had to dig around to find the right footprints for certain parts.
Hi, your mental model is essentially correct, though it took me a good few evenings over a couple of weeks to get the workflow down in fusion 360. The electronics retailer will usually have the footprint and 3d model available on the component page. You can then import it, define which pins you want connected to each other in the footprint and in the PCB editor you can drag the routes (wires) to connect them.
Printing is way cheaper than I initially thought it would be - I paid £35 or so, including delivery and 5 of them arrived in 5 days. You can get cheaper delivery though. Also most of that cost is shipping and the setup fee - the marginal cost for each additional PCB print in the order is on the order of low single digit dollars.
Tbh my circuit was fairly simple so I just took a bit of a chance (and some extra care wiring things up). I think there’s a subreddit where people give feedback though I haven’t submitted anything.
As a hobbyist, I have had a good experience using EasyEDA [0]. It's free to use, with the caveat that you are pretty locked in to their PCB ordering service from China. However, pricing is crazy good, like <$50 total for 5 PCB's (although there will be tariffs).
Regarding your mental model, it's more like a 2-step process. First, you draw the netlist, which is the electrical circuit diagram. It's this stage you ensure there are no short-circuits, etc. Then in the second stage, you drag-drop the components to the physical layout you want. The software then has an auto-router that references the netlist and automatically generates the first pass of PCB traces. You can tweak them if you wish. The EDA software also has a rules engine that checks for correct trace spacing, vias, etc.
For a "baby's first PCB", I bet you have more skills than you realize and I would encourage you to just give it a shot. Also, if you make a small mistake, you can manually "bodge" the board by cutting wrong traces with an exacto knife and/or soldering wires to the pads.
Everything else just comes from experience! If you're staying in the sub-kHz (audio) range, you probably won't need the crazy high-frequency tricks/trace capacitance/trace-length-matching concerns.
Does EasyEDA not allow you to download gerber files anymore? Gerbers are universal and you'd be able to send them to any fab you wanted. Obviously EasyEDA being sponsored by JLC means they make it easy to order through JLC.
Depends on complexity. The article gives a price, for 5 PCBs which isn't unreasonable. However this was a simple PCB that used a lot more physical space than it would need to (for this application most of the space was needed because of the physical space the buttons/sliders needed so it was needed so this isn't a criticism). If you want to make a small PCB much more work is needed. This was a few analog sliders and buttons - no high speed digital data, if you are designing a computer (even Apple II level complexity) it is a lot harder. If you are designing a radio there are a lot of complexity. If you want to get this FCC (whatever your local government is) certified there is a lot more complexity.
This project is something that should be easy for someone with basic CAD experience. However many projects require a lot more complexity, so don't think that because most people could figure this PCB out in a day make you think anyone can do more complex PCBs, things get complex fast.
If the board is small (10x10cm or less) it will be almost completely free, like single-digit dollars, through somewhere like JLPCB. So I’d say don’t worry too much about that, just jump in and try!
As for actually designing, it’s a little more complicated than that but not by much. I did my first pcbs with KiCAD ~5 years ago by pretty much just guessing and googling where things were. Completely feasible if you have 0 background experience.
jmb99 already said the part about cost/price. I just made a PCB for someone’s Halloween costume and it was only the 4th PCB I ever made. (So far I’ve used PCBWay for all 4 but since I’m in the US I also ended up doing a rush order from US-based Osh Park because I was panicking about how long the shipping was taking. Tariff situation has made shipping from China to the US more complicated. I found out DKRed, which is part of DigiKey, also makes PCBs in the US.)
For designing it I’d check out a kicad 9 tutorial playlist. You don’t need to know everything but it helps to know the right things, like how to run the design rules checker to make sure your PCB layout conforms to your schematic. There are a bunch to choose from but this one seems good: https://youtu.be/4YSZwcUSgJo
I haven’t done this but you can also try submitting your PCB design to /r/PrintedCircuitBoard subreddit for review, and they can also answer questions there.
What an awesome project. It looks fabulous!
Reminds me of the Dato Duo I have.
The "Dato Duo" is also a synth aimed at kids. It allows 2 kids to play together. it is made by a Dutch company called Dato (https://dato.mu). Their latest musical invention the "Dato Drum" had a successful Kickstarter and is shipping now. This drum machine allows even more kids to play together.
PS: As the owner of a Dato Duo I can share you a little secret: it's also fun for adults :)
The traditional approach is you give noisemaking toys to your niblings, not your own children.
This sounds like a lesson I’m going to be learning the hard way
Good parenting is doing things the hard way.
So why not go all in with a full set of acoustic drums?
Do you have $800? I'm trying to get my daughter a full set of acoustic drums (though odds are her brother will use them more even though he plays clarinet and she does percussion). I've seen full sets for as little as $30 - but it doesn't take much checking to realize they are not worth it even at that price. Good sets quickly cost more, but $800 is a good starting point for a set that isn't unusable.
Your daughter is so lucky! I meaning the physical UX is very reminiscent of teenage engineering, looks great! The more I was scrolling down the article the more I hoped for an « order » button :)
Looks like a fun project. I can highly recommend Teensy Audio Library for audio projects: https://www.pjrc.com/teensy/td_libs_Audio.html
Were you aware of the Dato Duo (https://dato.mu/)? It's very cool for kids, except for the fairly steep price point.
The advantage is that it's limited, so it greatly reduces the wall of difficulty to manage to get some 'nice-sounding' music (mostly the restriction to the pentatonic scale). However, kids still manage to find the most horrible-sounding settings, and insist on keeping them as is...
Cool! Reminds of the Music From Outer Space synth in which the designer makes the claim that it "can actually get a child away from a television" and includes a video to prove it.
https://www.youtube.com/watch?v=i6M_KrZByz4
MFOS Weird Sound Generator
https://musicfromouterspace.com/index.php?CATPARTNO=WSG001&P...
This is absolutely FANTASTIC, and I am humbled by your mad skillz!
My son and I are also fascinated by the sweet, sweet synth sound, but as I have no discernible talent, we went this route:
https://www.sweetwater.com/store/detail/Nts1Mk2--korg-nutekt...
Which, unfortunately, has a HUGE learning curve in terms of operation.
I was too fascinated by the different thumb nail lengths to concentrate much on the video.
I trained as a classical guitarist, so I maintain some longer nails on my right hand :)
Wow, what an amazing demo for such a simple synth. Great work! If you ever start a Kickstarter, I’d be happy to donate. If it inspires some kid out there to get into music production, it’s a win for me :)
Kinda funny but my adult son has taken an interest in guitars and keyboard and that has me working on MIDI routers with AVR-8 and building an ESP32 based synth module.
This is great. I’m going to start making something like this, but with some cut apple wood knobs, for my birds.
Looks so nice! The sam is a midi synth chip right? Super cool. How/where did you get the knobs?
Thanks! Yes it's a little digital synth that receives MIDI.
I used Chroma Cap knobs: https://store.djtechtools.com/products/chroma-caps-knobs-and...
Aah kool, i had one in a arduino format board, was great to cycle through all the instruments randomly + some sequence/chords. Instant Aphex Twin
I'm not a kid. I still want it !
Same. It's a solid four-note ARP that sticks to a fixed set of musical keys. You literally can't make bad sounding music with this.
A more grown-up version of this would be 16 notes, with variable length patterns (4-16?), and a "swing" function. A little bit of I/O mux under the hood and I bet this design could be expanded in that way. Or maybe you just daisy-chain multiple sequencers?
This is great. I did a similar thing when my kids were young (revived an old, dead Kawai synth with a Raspberry Pi and sound fonts), but doing it with semi-discrete circuits seems a lot more fun.
Wow! Looks great and very inspiring. Great idea to make separate components that can be connected - something like a drum machine, sequencer, maybe even a chord synthesizer? It can be constrained such that you are always diatonic, you could have a mode knob too.
Jamming with other people can be a life changing experience, and to do that as a child would be a great privilege to have.
Im not sure youre aware of this but look up modular synthesizers. This is how electronic music was made starting in the 60s/70s
Yes exactly, it would be great to be able to sync the clocks so they all ‘just work’ together. And maybe also a module that gives all the other synth parameters for the more advanced user too. I say it’s for my daughter, but I actually would love this too.
As someone who has never 3d printed anything, I'm surprised by how clean the case looks as opposed to what we usually see. Why is it so smooth?
The surfaces you're seeing in the pictures are almost all the "bottom" surface that was printed directly on the build plate. It basically just picks up the texture of the build plate and is otherwise smooth. That's actually a fairly bumpy build plate they printed it on (which lots of people like for aesthetic reasons).
That said modern 3D printers are good at producing pretty nice parts these days, especially if you print with small layer heights. You might be underestimating the possible quality of 3d printed objects.
This is an inspiring project! I would love to see more stuff like this and updates if you decide to evolve the project further.
Thanks so much! Please drop your email here and I'll keep you updated with any next steps: https://tally.so/r/Y55dXv
The korg monotribe is magic for kids
This is fantastic, as a hardware synth lover and a dad you’re making me pretty jealous.
This is awesome. Just awesome. Love that it looks like a baby toy and packs enough punch to get a kid about 20 years up the line of music understanding.
This is awesome. I had vibecoded something similar called https://chippytune.com for myself. Still working on wav support though
Makes me wonder what the difference, in definition, is between a sequencer and a synthesizer? Is this really a synthesizer, or is it really a sequencer?
Yes, I'm splitting hairs about semantics.
A synthesizer is generally a higher-level ready-to-use product containing any number of oscillators, sequencers, and other circuits and bells and whistles under the hood. A device with an oscillator and a sequencer qualifies as a basic synth.
At a lower levels you find modules like sequencer, oscillator, etc. They are generally not used by themselves: you plug a sequencer into an oscillator to make use of it, just like a standalone oscillator by itself simply makes a continuous noise that gets old quickly. A synth does that connection for you and exposes the controls.
(To make things even more fun, the lines between lower-level audio modules are often blurred. For example, the difference between a sequencer and an oscillator can be best summed up as: the former is commonly designed for unipolar control rate signal change where you can specify exact level per step, while the latter is designed for bipolar audio rate signal change between two predetermined extremes—however, as the “designed for” hints, you could configure some sequencers to output a bipolar signal changing so fast it is audible, just like you could run a square wave oscillator so slowly that it becomes a 2-step sequencer.)
The linked project is both. A synth makes sounds, and a sequencer controls the sound over time usually with note on/off data. This sequencer has 4 steps before looping back to the beginning. To simplify, think of a sequencer as the music box drum and the synth as the tines in a music box.
A sequencer is always in steps. A synthesizer has a signal generator and can modulate a single step. This toy is both a synthesizer and a sequencer, but since you cannot toggle the 4 steps off, it will always be a sequencer in addition to the synthesizer
The answer to your question is "yes".
It is a synthesiser AND it is a step sequencer.
Regarding case material for productizing, you could consider a combination of plywood and bent sheet metal, eg like a Moog. Also check out dato.mu for a few examples of kid proof synth enclosures.
Would bent sheet metal have any sharp corners or edges? For kids it's probably best to avoid those.
You can debur it as part of the manufacturing process, and then when it gets powder coating it smooths out even more. But you can just embed the sheet metal edges in a groove on a wooden side.
That depends on how much effort your spend on finish work. Files and sandpaper works wonders, but that take time. Or you can fold the edges over so that the sharp edges are on the inside (cars do this). The plywood is likely to cover all those sharp edges - plywood is easier to shape than sheet metal so this is a common cheat that can look good if done right.
Very cool. Reminds me of things like the Blipbox myTRACKS and the CHOMPI.
I'm a 44 year old man and I would love this - for years I've tried to dabble with music with much lack of success - but this looks really fun to play with. Great job.
I've been messing around making a small web based project that does something similar if you're interested in trying a dabble: https://shantylab.com
If you want a synth you can buy that has a similar playing style, you could check out the Modern Sounds Pluto: https://www.modernsounds.co/pluto (the original run is sold out but you can find them on ebay/reverb)
It's two of these 4-note step sequencers with some fun timing randomness. Similar to the OP's synth it uses knobs to set pitches but the knobs are picking notes from a specific key so they always sound good together. It's a lot of fun to play and doesn't require any musical knowledge!
The problem with music is you can't dabble. You need to dedicate half an hour per day for a few weeks before you reach the point where you are not terrible. You need years of dedicated practice before you can call yourself good. Finding that time is hard. Still making your own music is run and so I encourage you to press through.
Not trying to get good is a liberating step. I never was and never will be good at music, but it’s still fun to play loud punk-ish tunes on a guitar, or twiddle the knobs on a faux-303, none of which requires years of your life.
There are also free software synths and DAWs available. GarageBand is the obvious one if you use macOS. I had lots of fun with that and with NanoStudio on iPad. I also own a Pocket Operator, which is fun and very mobile, but a bit pricey.
Go grab a Teenage Engineering Pocket Operator, it's definitely worth a try ! I personally recommend the PO-33 (KO!), it is fun and easy to play with :)
The POs are fun to play with, but from experience I would much rather recommend getting a used mk1 Novation Circuit. For $150 - $200 you have a four track drum machine plus two tracks of a great synth engine, with a built in mixer and simple effects, midi in if you want to use a keyboard, and the thing is still compact and battery powered.
This is great, i’d kickstart it, my 5 year old would love it.
that's great! may your daughter make great use of it!
love the fact that your step sequencer even has a display to tell you what note you are adjusting to and from. i've always found that tuning synths and sequencers both analog and digital can be a pain because you can forget the note (or you don't have a good set of ears or perfect pitch) even if the result sounds good.
Totally rad! Makes me think about what kind of simple programming could be possible with a minimal HCI like this.
Great work! This brings back memories of futzing with knobs on a boombox as a kid.
For your sake, I hope you built a heaphone jack.
Thank you! Unfortunately I decided to save that feature for v2!
Strong sugestión for v2: Add a hidden knob to regulate the max volume. Kids love to raise it to the max.
(In a tablet, I had to secretly add some transparent tape between the speaker and the plastic cover case.)
It's beautiful and the demo video shows how someone with music background can make even such a limited tool sound so amazing.
As a father to a daughter this warms my heart. Well done daddy! Points to you!
So cool, I think all kids would love this
is it feasible to built one with a PCB? just straight to the UNO like your initial prototype - did that work ok?
Dad of the year <3
This is very impressive, it looks great!
I can't put into words how awesome this is. Perfect demo.
My kids would love this.
Reminds me of the concept of the Data DUO, very inspiring
Absolutely, Kickstarter is a good idea
Wow looks professional
The other day I came across a post on Facebook that was just some guy grousing that the new Teenage Engineering gadget looked like "a baby's activity center". And now we've come full circle: a baby's activity center that's actually not far off from Teenage Engineering kit.
wow
Another good option for a child: https://www.eltamusic.com/solar-42
On a serious note: https://www.ericasynths.lv/shop/standalone-instruments-1/bul...
Perhaps more realistically, Teenage Engineering products: https://teenage.engineering/store
yes, the pocket operator is a great gift for 8-9+ year olds if you're not as talented as OP :D