posts tagged with the keyword ‘audio’


Noisemaker from the 1980s4938

I came across a treasure in one of the (many) boxes of “old things” in the basement. What you see is a Radio Shack project box with a speaker and a switch on it. Yeah, it’s a noisemaker, and I built it in the mid-1980s.

Fun fact, I used to do electronics in high school, and while I’m not sure this was a project we did in class, I’m guessing I may have built it around the time I was in school. It was probably around 1985 or so, if I had to guess. (I think I took two years of electronics classes.)

Noisemaker from the 1980s4939

The speaker has a “grill” that appears to be made from a metal screen, maybe from an old scrap window screen? I do know it would have been built with whatever stuff was around the house. I think I used Elmer’s glue to attach the screen to the speaker. It seems to have held up! The lettering for the “ON” label was most likely done using Liquid Paper and there’s a bit of clear Scotch Tape covering it as a protective layer. This also held up well!

Noisemaker from the 1980s4940

There’s a hole in the case. I’m not sure why. If I had to guess, I probably burned it with my soldering iron. I should say “Solder Gun” because at home we had one of these, and I don’t know if it belonged to my dad and I used it, or he bought it for me, but I do remember it wasn’t easy to solder with. At the time I didn’t realize this wasn’t the preferred tool for delicate electronics work…

Noisemaker from the 1980s4942

It looks like the soldering joints on the speaker held up fine… not so much for the masking tape, which dried up and lost its “stick”. I guess I just taped the speaker down, and used the tape as an insulator for the speaker contacts. (I did not know about hot glue yet.)

Noisemaker from the 1980s4945

Let’s pop this sucker open! Solid core wire and a 9 volt battery connector are visible. There’s also a piece of paper that I assumed was to insulate the metal battery housing from the electronics. And then…

Noisemaker from the 1980s4946

I took out the piece of paper and… oh my gawd, I actually documented this thing. There’s a circuit diagram and a Bill of Materials! This explains so much about my life, and honestly, I’m sort of proud of teenage me. Good Job, Petey!

And no, it’s not a proper schematic, but it’s approximately how I document most of my work/projects nowadays, using circuit diagrams, like you might create with Fritzing.

Noisemaker from the 1980s4947

Finally! We’ve got a perf board inside with a few components soldered onto it, and and rudimentary strain relief by running the wires through the mounting holes of the perf board. Well done, Petey!

Noisemaker from the 1980s4949

Let’s flip it over and… oh my gawd, the soldering! Sheesh! Now I am embarrassed! But this does lead me to believe I did this project at home, since that’s where I was using a giant soldering gun and giant solder not quite suitable for delicate electronics. Oh well, at least my soldering skills have improved since the mid-1980s!

Oh, in case you’re wondering how it works, look at the diagram for a clue. You touched the metal bolt sticking through the enclosure and the top metal piece of the enclosure, and you completed the circuit, and could get weird tones based on how much you touched and how hard you pressed. I was really hoping to include a video but sadly, it did not work after 30 years of sitting in a box. Drat!

(And yes, I’m really tempted to build a new version of this to see what it sounds like!)



Now that summer is over and the cold months have arrived we no longer sleep with fans running, but that means we sleep without the sound of fan running, and who can sleep with all that quiet?

The wife asked if I could make something that sounded like a fan, which if you know me, is right up my alley. I grabbed a Raspberry Pi Zero and got to work. I found an audio clip of an oscillating fan (wow, there are tons of fan videos on YouTube!) and dropped it onto an SD card with Raspbian and mpg123 and had something working.

The Raspberry Pi Zero has no built-in audio output so in the past I’ve tried using a USB audio dongle, but the one I tested failed miserably in The Sonic Titan so I decided to go a different route. I used a 1080P HDMI Male VGA Audio Video Converter Adapter Cable for PC Laptop PS3 Xbox I got from eBay and then sent the audio out via HDMI so it would go to the adapter. I also needed a Mini HDMI adapter for that to plug into. It works fine, and I’ve not seen the same audio problems I did with the USB dongle.

As you can see from the photo I used a custom enclosure designed by SparkFun and modified with a stabby knife. ;)

I also used a set of powered speakers, and a dual USB power supply from Monoprice. This was hacked together rather quickly, but it all works quite well. We just plug it in before bedtime and within 30 seconds we’ve got our noise. (It also helps drown out the sound of my cat trying to wake us up at 6am.)

The thing I find most amusing about this project is that even though the Raspberry Pi Zero is a “$5 computer” it comes out to almost $30 when I add in the power supply, SD card, speakers, and HDMI audio adapter. Still, I think it’s a better option than running a full desktop computer or laptop with white noise all night. (Which apparently some people do. I’ve also heard that an old phone or tablet is a good option.)

The thing I like most about “Sleepy Noise Machine” is that is was something I could easily slap together with existing parts I had around the house. I mean, you can buy a white noise machine, but why bother when you can make your own?


NoiseMaster VI

Once again we’re moving along in our noisemaker series and this time we’ve got a few new things going on, but again, we’ve got a device that makes noise when you press a button. This is also the first noisemaker that features an external speaker.

NoiseMaster VI

The enclosure is another simple wood affair, and there’s a push button, and we’ve also got a… gear? Yes, there’s a gear, and under the gear is a copper board which is usually used for making PCBs, but in this case it’s used as a thin surface that allows the gear to mount to the shaft of a gear motor hidden below.

NoiseMaster VI

Just like with the last noisemaker, I used some Forstner bits to hack out a large hole and then cover it with a plate. It makes the surface look nice, and the inside/bottom is a hidden mess (which is totally fine, right?) This noisemaker has one more trick up its sleeve, I mean, it would if it had a sleeve.

NoiseMaster VI

There’s no microcontroller in this one. The electronics consist of a power supply running to the button, then to the motor, and then to the speaker. That’s it. Interestingly enough, you can get some pretty cool noise happening just by running power through a motor and speaker. Since it’s a gear motor it’s already got a great whirring sound to it, so the speaker helps amplify it. And, the bonus is that by affecting the spinning of the motor, you affect the sound. (See the video below for a demo.)

NoiseMaster VI

When I started this project I had to find old speakers, and this is from a set I rescued from the trash and had to bust apart the old wooden cabinets that had way too many screws in them. (I had these sitting under my desk at work for a few months.)

NoiseMaster VI

Still, they’ve got a funky look and mounting them just took some scrap wood, plastic strapping, and a few screws. Easy speaker stand!

NoiseMaster VI

There’s a few more two-piece noisemakers coming, but this was the first one in the series I finished. Stay Tuned!

This is just one post in a series about noisemakers. Check out the other posts as well:


NoiseMaster V

We’re moving along in the series with yet another noisemaker. This one features a control interface! Which is to say, there’s a potentiometer involved to alter the sound. This one is mainly wood with some pieces of HDPE added in. Originally I had the speaker mounted to the front, and it sort of looked like a radio, but for some reason I can’t remember, I moved the speaker to the back of the unit.

NoiseMaster V

Besides just having a button to activate the sound we’ve added a slide potentiometer. I grabbed a big pile of them from eBay years ago to have on hand, and I still have a lot of them around so I figured an audio project would be a good use for one. You may notice that the green button I used is a pretty close match to the green filament I used for 3D printing the potentiometer mounting plate. That worked out well.

NoiseMaster V

I designed the mounting plate so it could hold the potentiometer in place using two #4-40 bolts, which screw directly into the potentiometer to hold it to the plate. I then added four more mounting holes so the plate could mount to the enclosure. I kept those #4-40 for consistency. Again I’ve gone with the green PLA for the plastic parts, creating some interesting contrast between 3D printing with plastic and wood working. (And yes, there’s also blue HDPE pieces on this noisemaker.)

NoiseMaster V

Because the slide potentiometer needs to mount fairly close to the surface, and I’m using wood that is well over a 1/4″ thick, I had to chew out a bunch of the wood to make a big hole for things to work properly. I used some Forstner bits to make a rough slot in the top. Since the plate will cover it the beauty (or lack of beauty) of the slot didn’t matter much. (I’ve never really used Forstner bits in the past, but they’ve become a favorite of mine in recent years.)

NoiseMaster V

Our control interface, a button to activate the sound, and a slide potentiometer to alter the sound. I tried to position them for comfort when using two hands, though you can sort of operate it with one hand. The handle (knob?) for the potentiometer is also 3D printed, though it is covered in black Plasti Dip which gives it a nice feel when touched. I thought about making spares in case one “disappeared” during the show, but I never made more, and it did not disappear.

NoiseMaster V

The knob model had some rounded edges, and once again I’ll have to say I was pretty impressed with the Maker Select Plus at being able to handle it. It did take me a few iterations to get a knob that I liked, but this one turned out pretty well for a quick ‘n dirty project. It slid onto the potentiometer shaft very well as a press fit, and I felt pretty good that it would not have been easy to remove without some effort.

NoiseMaster V

And of course, one last hack… The screws I had were a bit too long for mounting the speaker as I did for some other noisemakers so I ended up hot gluing a white plastic puck behind the speaker to increase the distance so the screws would work. The puck was another thing I grabbed from the junk pile at work, because you never know when you’ll need some small white plastic pucks.

This is just one post in a series about noisemakers. Check out the other posts as well:


NoiseMaster IV

The next noisemaker in our series is a bit more sophisticated in its construction and finish. This is the first one that features painted wood, and as a nod to what one of my design instructors used to call the “El KaBong” I added a large arrow pointing towards the button that the user is meant to press.

NoiseMaster IV

This one is also a “standoff enclosure” (is there another name for it?) where there is a top and bottom surface, separated by legs (or standoffs.) The standoffs were 3D printed, and I do have to say that the MSP did a good job. The standoffs for the speakers were also printed, and those required a bit more detail to work properly…

NoiseMaster IV

You can see in the model the small indent needed for the speaker to mount. This is due to the metal from the speaker mounting holes being present, and not providing a flush surface for mounting. There’s also countersink holes designed into the bottom of the legs, to allow the screws to sit flush. I do enjoy being able to model parts that fit exact, with the holes for screws the perfect dimension. As this whole project moved forward I found myself combining wood working with 3D printing, and I liked it.

NoiseMaster IV

I think it turned out well. I didn’t really plan for the “Xmas” colors, but I had green filament loaded up, so I just went with it. The speaker is from a weird set of car speakers I got from the Hack Rack at Milwaukee Makerspace. They were encased in a plastic enclosure that was not fun to tear open, but the speakers were nice, and worth the time…


Speaking of time, while the first few noisemakers I built were quick ‘n dirty, this one looks like it took a lot more time. At this point I was working on multiple noisemakers, so I’d still have plenty to do while paint or glue was drying, or I was waiting for parts to 3D print. Once again, this one just has an ATtiny85 making the noise. At this point I still had a pile of ATtiny boards and kept stuffing them into noisemakers. (I did branch out a bit later, though.)

NoiseMaster IV

This is just one post in a series about noisemakers. Check out the other posts as well:

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