Custom Slimline CD Player Hides Out Under Speaker

March 27, 2025 by Tom Nardi 10 Comments

In the era of digital streaming, the market is full of wireless speakers that will play content from your smartphone or pull it down from the Internet directly over WiFi. But if you’re feeling a bit nostalgic and want to throw on one of your old CDs, well, you might have a problem. That’s the situation [Chad Boughton] recently found himself in, so he decided to build a compact CD player that could discreetly connect up to his fancy Klipsch speaker.

The optical drive itself was the easy part, as [Chad] already had a laptop-style drive in an external enclosure that he could liberate. But of course, the speaker wouldn’t know what to do with an external disc drive, so there needed to be an intermediary. Enter the Raspberry Pi.

It might not look like it at first glance, but that’s a Pi 3 tucked into the back of the 3D printed frame. It would have been too tall in its original configuration, so [Chad] removed the USB and Ethernet ports; a modification we’ve covered in the past. Of course, he still needed to use the USB ports, so he ended up soldering the two cables — one to the CD drive and the other to the back of the speaker — directly to the Pi.

When plugged into the Raspberry Pi, the Klipsch speaker shows up as a USB audio device, so the software side of things was relatively simple. [Chad] installed VLC to handle CD playback, but he still needed a way to control everything. To that end, a IR receiver hooked up to the Pi’s GPIO pins means the Pi can detect the signals coming from the speaker’s original remote and pass the appropriate command on to VLC. The whole thing is very well integrated, and you could be forgiven for thinking it might be some kind of stock upgrade module at first glance.

Despite recently celebrating its 40th birthday, the CD is unlikely to completely disappear from our lives anytime soon. Manufacturers can turn their back on the standard if they want, but so long as folks still want to play them, they’ll keep coming up with inventive ways to make it happen.

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Decoding Compact Disc Audio From Scratch

February 16, 2023 by Lewin Day 36 Comments

In the rare case we listen to an audio CD these days, we typically rely on off-the-shelf hardware to decode the 1s and 0s into the dulcet tones of Weird Al Yankovic for our listening pleasure. [Lukas], however, was recently inspired to try decoding the pits and lands of a CD into audio for himself.

A fair bit goes into decoding Red Book digital audio.

[Lukas] did the smart thing, and headed straight to the official Red Book Audio CD standard documents freely available on archive.org. That’s a heck of a lot cheaper than the €345 some publishers want to charge. Not wanting to use a microscope to read the individual pits and lands of the disc, [Lukas] used a DVD player. The electrical signals from the optical pickup were captured with an oscilloscope. 4 megasamples of the output were taken at a rate of 20 megasamples per second. This data was then ported over to a PC for further analysis in Python.

[Lukas] steps us through the methodology of turning this raw data of pits and lands into real audio. It’s a lot of work, and there are some confusing missteps thanks to the DVD player’s quirks. However, [Lukas] gets there in the end and shows that he truly understands how Red Book audio really works.

It’s always interesting to see older media explored at the bare level with logic analyzers and oscilloscopes. If you’ve been doing similar investigative work, don’t hesitate to drop us a line!