One-button Audiobook Player Made From A Raspberry Pi

November 1, 2012 by 35 Comments

[Michael Clemens] was looking for gifts for his Grandmother’s 90th Birthday. She is visually impaired and loves to be able to listen to audiobooks. The problem is that she doesn’t really get the hang of using electronics. He made things easy by building her a one-button audiobook player.

The Raspberry Pi board is a perfect solution for this project. It’s cheap, it has an audio port, it has storage for the books on the system SD card, and it runs Linux. The last part is key as it made things very simple when [Michael] started pulling together the various components.

When the RPi is powered up it drops immediately into a Python script which loads the audio track and places the music player daemon in pause. The yellow button seen above works as a play/pause button when clicked. If the listener misses something she can hold the button for more than four seconds to go back one track. Loading new books is easy too. [Michael] copies the files onto a thumb drive with a special volume label. When plugged into the RPi USB port the script automatically copies the book and starts playing when the drive is removed. He included a video demo on his project page linked above.

Audio-Forward Case Mod Of Classic 90s Portable TV

April 24, 2026 by 11 Comments

The humble cathode ray tube (CRT) was once the technology behind almost all of our televisions and computer displays. Its replacements, from LCD screens to OLED and others, are generally cheaper to make and better to look at. Old televisions were comparatively large as well, but their size can be an advantage for people like [ManicMods] aka [Jeff]. His latest build ditches the CRT from an old Bently portable TV and uses the huge space available in the case for a hi-fi audio system and some other parts that turn it into an impressive portable home theater system.

After removing most of the internals of the TV, the first part to go in is the stereo and subwoofer combo as it takes up the most amount of space. The subwoofer section points downward and the two stereo speakers are mounted to the sides. To free up the most space inside, the new display is mounted forward of the original bezel, with a new 3D printed one helping to hold it in place. Behind it goes a Raspberry Pi, loaded with the moOde audio player, a high quality DAC for audio output, and a 1 TB SSD with [Jeff]’s uncompressed audio library. Most of the ports are extended out to the case including the SD card slot so other operating systems can be loaded on the Pi, and there are a ton of options for hooking up external speakers and displays as well, making it an extremely modular and expandable portable media center.

Also added to the finished product are a few small game controllers, since the Pi is perfectly capable of playing retro games, as well as a small wireless keyboard and trackpad combo. Although the CRT’s demise will be felt harder by some than by others, the original look of the case is preserved somewhat by keeping the original tuning display and locations of the original control buttons and knobs. If preserving the CRTs are of upmost importance, though, this build used a pair of them in a VR headset.

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Soviet CDs And CD Players Existed, And They Were Strange

March 29, 2026 by 11 Comments

Until the fall of the Soviet Union around 1990 you’d be forgiven as a proud Soviet citizen for thinking that the USSR’s technology was on par with the decadent West. After the Iron Curtain lifted it became however quite clear how outdated especially consumer electronics were in the USSR, with technologies like digital audio CDs and their players being one good point of comparison. In a recent video by a railways/retro tech YouTube channel we get a look at one of the earliest Soviet CD players.

A good overall summary of how CD technology slowly developed in the Soviet Union despite limitations can be found in this 2025 article by [Artur Netsvetaev]. Soviet technology was characterized mostly by glossy announcements and promises of ‘imminent’ serial production prior to a slow fading into obscurity. Soviet engineers had come up with the Luch-001 digital audio player in 1979, using glass discs. More prototypes followed, but with no means for mass-production and Soviet bureaucracy getting in the way, these efforts died during the 1980s.

During the 1980s CD players were produced in Soviet Estonia in small batches, using Philips internals to create the Estonia LP-010. Eventually sanctions on the USSR would strangle these efforts, however. Thus it wouldn’t be until 1991 that the Vega PKD-122 would become the first mass-produced CD player, with one example featured in this video.

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Simple MIDI Sample Player Runs On ESP32

March 19, 2026 by 4 Comments

[Jakub] is a musician, and found himself in need of a simple way to trigger samples via MIDI when on stage. So many commercial solutions exist, but most were overkill for the job or too messy and complicated to justify their use in a live environment. Thus, [Jakub] worked up Samplotron to do exactly the job needed with a minimum of fuss.

The project is based around the ESP32. It’s effectively a lightweight hardware sampler that can trigger sounds on command via MIDI. Sample data is loaded from an SD card, which also stores the device configuration. The Samplotron plays back mono 16-bit WAV files at 44,100 Hz, delivering audio via an ES8388 audio codec module connected via I2S. Two encoders are used to control the device, with a menu system presented via an SSD1309 OLED screen. Samples can be loaded and managed via this interface, and it allows tweaks to be made to volume levels and one-shot/loop playback as needed. MIDI input to the device is simply handled via the onboard UART functionality of the ESP32 itself.

It’s a neat little bit of music hardware that does exactly what [Jakub] needs and nothing more. We’ve featured similar builds before, like this neat RP2040 soundboard. If you’re building rad custom hardware for your own musical adventures, we’d love to know all about it. 

Belting Out The Audio

December 8, 2025 by 17 Comments

Today, it is hard to imagine a world without recorded audio, and for the most part that started with Edison’s invention of the phonograph. However, for most of its history, the phonograph was a one-way medium. Although early phonographs could record with a separate needle cutting into foil or wax, most record players play only records made somewhere else. The problem is, this cuts down on what you can do with them. When offices were full of typists and secretaries, there was the constant problem of telling the typist what to type. Whole industries developed around that problem, including the Dictaphone company.

The issue is that most people can talk faster than others can write or type. As a result, taking dictation is frustrating as you have to stop, slow down, repeat yourself, or clarify dubious words. Shorthand was one way to equip a secretary to write as fast as the boss can talk. Steno machines were another way. But the dream was always a way to just speak naturally, at your convenience, and somehow have it show up on a typewritten page. That’s where the Dictaphone company started.

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DIY MP3 Player Inspired By The IPod

August 1, 2025 by 6 Comments

These days, the personal MP3 player has been largely replaced by the the smartphone. However, [Justinas Petkauskas] still appreciates the iPod for its tactility and portability, and wanted to bring that vibe back. Enter JPL.mp3

The build is based around the ESP32-S3 microcontroller. It’s hooked up with a PCM5102 DAC hooked up over I2S to provide quality audio, along with a micro SD card interface for music storage, and a small IPS LCD. The best feature, though? The mechanical click-wheel which provides a very tactile way to scroll and interact with the user interface. Everything is assembled into a neat 3D printed case, with a custom four-layer PCB lacing all the electronics together.

On the software side, [Justinas] cooked up some custom software for organizing music on the device using a SQLite database. As he primarily listens to classical music, the software features fields for composer/piece and conductor, orchestra, or performer.

[Justinas] calls the final build “chunky, but nevertheless functional” and notes it is “vaguely reminiscent of classic iPods.” We can definitely see the fun in building your own personalized version of a much-enjoyed commercial product, for sure. Meanwhile, if you’re cooking up your own similar hardware, we’d certainly love to hear about it.

When A Record Player Doesn’t Work Due To Solid State Grease

July 20, 2025 by 24 Comments

Normally, mechanical devices like record players move smoothly, with well-greased contact surfaces enabling the tone arm to automatically move, the multi-record mechanism to drop down a fresh disc, and the listener to have a generally good time. Unfortunately, the 1972-era ITT KP821 record player that [Mark] got recently handed by a friend wasn’t doing a lot of moving, with every part of the mechanism seemingly frozen in place, though the current owner wasn’t certain that they were doing something wrong.

Fortunately, this record player was in exceptionally good condition.. The primary failure was that the BSR record player mechanism, with its many touching metal surfaces, was suffering from a bad case of solidified grease. Although this is easily fixed with some IPA and a lot of elbow grease, the biggest trick with these mechanisms is putting it back together after cleaning, with many seemingly randomly shaped parts and every single E-clip that the manufacturer could design for and source at the time.

With that complete, this just left some pot cleaning and replacing a busted fuse in the amplifier section. The selenium rectifier was still functional, as were the SGS TAA621AX1 audio amplifier ICs. Despite the age of this ‘portable’ record player, both its BSR mechanism and the twin speakers that are part of the record player are in remarkably good condition. Much like with a car, it seems that you just have to swap out the liquid-y elements before they turn into a solid.

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