Terminal DAW Does It In Style

April 30, 2025 by Fenix Guthrie 30 Comments

As any Linux chat room or forum will tell you, the most powerful tool to any Linux user is a terminal emulator. Just about every program under the sun has a command line alternative, be it CAD, note taking, or web browsing. Likewise, the digital audio workstation (DAW) is the single most important tool to anyone making music. Therefore, [unspeaker] decided the two should, at last, be combined with a terminal based DAW called Tek.

Tek functions similarly to other DAWs, albeit with keyboard only input. For anyone used to working in Vim or Emacs (we ask you keep the inevitable text editor comment war civil), Tek will be very intuitive. Currently, the feature set is fairly spartan, but plans exist to add keybinds for save/load, help, and more. The program features several modes including a multi-track sequencer/sampler called the “arranger.” Each track in the arranger is color coded with a gradient of colors generated randomly at start for a fresh look every time.

Modern audio workflows often span across numerous programs, and Tek was built with this in mind. It can take MIDI input and output from the JACK Audio Connection Kit, and plans also exist to create a plugin server so Tek could be used with other DAWs like Ardor or Zrythm. Moreover, being a terminal program opens possibilities for complicated shell scripting and other such Linux-fu.

Maybe a terminal DAW is not your thing, so make sure to check out this physical one instead!

Rockbox 4.0 Released

April 19, 2025 by John Elliot V 23 Comments

It’s traditional to launch new software on April Fool’s Day, which is when we heard that Rockbox 4.0 has been released. But, in this case, the venerable MP3 firmware actually did update after a long absence. It’s great to see that good old Rockbox is still kicking along. We first mentioned Rockbox here at Hackaday approaching 20 years ago. How time flies. There used to be a whole ‘scene’ around hacking Personal Media Players (PMPs), also known as “MP3 Players”.

We tracked down Rockbox contributor [Solomon Peachy] to ask for some simple advice: If someone wants to install Rockbox on a personal media player today, what hardware should they buy? [Solomon] referred us to the AIGO EROS Q / EROS K, which is the only compatible hardware still being manufactured and sold. Beyond that, if you want to buy compatible hardware, you’ll need to find some secondhand somewhere, such as eBay. See the Rockbox Wiki for supported hardware.

Smartphones and streaming services have subsumed the single-purpose personal media player. Will you put the new Rockbox on something? Let us know in the comments.

Exploring Hidden Lyrics On 1990s DCC Audio Tapes

September 11, 2023 by Chris Lott 18 Comments

Having a fondness for old and obscure audio and video media formats, [Techmoan] recently revisited the Philips Digital Compact Cassette (DCC) format introduced in 1992. Despite being billed as the successor to Philips’ original analog Compact Cassette format from 1963, DCC was short-lived and slipped away after only four years in 1996. [Techmoan] obtained a unique cassette that purports to be the only known published DCC tape which contains embedded song lyrics that scroll on the DCC player’s tiny screen in sync with the music — “Size Isn’t Everything” by the Bee Gees from 1993. Sure enough, he is able to demonstrate this in the video down below the break.

But, there’s more. For reasons unclear, this only happens on on this one Bee Gees’ album. But it turns out that many DCC tapes did in fact include lots of other metadata, and sometimes lyrics as well. But these were only visible using an unreleased Philips system called Interactive Text Transmission System (ITTS). It just so happens that the folks at the DCC Museum obtained a Philips prototype ITTS box and have been gradually hacking the protocol.

[Techmoan] demonstrates a modernized prototype version from Germany designed by [Thomas Falkner] called the ITTS video box NG. Using this, he runs through a bunch of DCC tapes from his collection, and finds a significant number of them were published with lyrics and metadata, presumably in anticipation of as ITTS launch. It’s interesting to see how some publishers spent a lot of effort to format this information and others seemed to just copy / paste over the bare minimum.

The more elaborate pages resemble what you might see on your teletext screens back in the day. On those albums that do have lyrics, the presentation can be different, as well. Lyrics from the Bee Gees album appear like text scrolling up on a terminal, with current phrases shown in yellow. Another album’s lyrics can be scrolled in different peculiar ways, including a one-word-at-a-time mode.

If this kind of historical dive into technology interests you, check out the talk that [Jac] and [Ralf] gave at the 2022 Supercon about DCC, and this video from 2018 where [Ralf] digs deeper into this topic. Also, [Jac] has some more recent details on hacking the protocol posted over on his Hackaday.io project page. If you want a more basic introduction to DCC, [Techmoan] introduced this format some years ago on his YouTube channel.

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DIY Programmable Guitar Pedal Rocks The Studio & Stage

May 16, 2023 by Donald Papp 10 Comments

Ever wondered how to approach making your own digital guitar effects pedal? [Steven Hazel] and a friend have done exactly that, using an Adafruit Feather M4 Express board and a Teensy Audio Adapter board together to create a DIY programmable digital unit that looks ready to drop into an enclosure and get put right to work in the studio or on the stage.

The bulk of the work is done with two parts, and can be prototyped easily on a breadboard.

[Steven] also made a custom PCB to mount everything, including all the right connectors, but the device can be up and running with not much more than the two main parts and a breadboard.

On the inside, the Adafruit Feather M4 Express board works with the audio board over I2S, a standard for sending serial digital audio between chips. Working with the audio itself is done with the Teensy Audio Library, providing a fantastic array of easy-to-use functions for processing and manipulating digital audio streams.

Together, all the right pieces are in place and [Steven] provides the code for a simple tremolo effect as a glimpse of what’s possible with the unit. Interested in going a bit further? [Steven] shares additional details about what’s involved in writing a custom effect from scratch using the Teensy Audio Library.

As mentioned, I2S is where it’s at when it comes to working with digital audio at the chip level, and our own Jenny List can tell you everything you need to know about I2S, a useful protocol that has actually been around since 1982!

Reading Data From A CD, With A Microscope

January 22, 2023 by Jenny List 18 Comments

There was a time when electronic engineering students studied the audio CD, for all its real-world examples of error correction and control systems. There’s something to be found in the system still for young and old though, and thus we were intrigued when we saw [Peter Monta] reading the data from a CD using a microscope.

CDs encode data as so-called pits and lands in a spiral track across a metalised surface, with a transition from pit to land signifying a logic 1 and a missing transition signifying a 0. Reading a section of the raw data is achieved in the first part of his write-up, but in the next installment he goes further into retrieving more data through stitching together microscope pictures and writing some code to retrieve data frames. He’s not quite at the audio playback stage, but he’s planning in the future to spiral-track a full image to rip an entire disc.

There are plenty of CD drives around to read audio the conventional way, but the techniques here still find a use where less ubiquitous media has to be read. In the last decade for example there was an effort to read the BBC Domesday Project from the 1980s, as it became clear that few of the original readers survived in working order.

Audio Old And New Meet In Perfect Harmony

December 30, 2022 by Jenny List 20 Comments

There’s an uneasy meeting in the world of audio between digital and analogue. Traditional analogue audio reached a level of very high quality, but as old-style media-based audio sources have fallen out of favor there’s a need to replace them with ones that reflect a new digital audio world. To do this there are several options involving all-in-one Hi-Fi separates at a hefty price, a cheaper range of dongles and boxes for each digital input, or to do what [Keri Szafir] has done and build that all-in-one box for yourself.

The result is a 1U 19″ rack unit that contains an Orange Pi for connectivity and streaming, a hard drive to give it audio NAS capability, plus power switching circuitry to bring all the older equipment under automation. Good quality audio is dealt with by using a Behringer USB audio card, on which in a demonstration of how even some digital audio is now becoming outdated, she ignores the TOSlink connector.

The rear panel has all the connectors for power, USB, network, and audio laid out, while the front has an array of status lights and switches. We particularly like the hand-written lettering, which complements this as a homebrew unit. It certainly makes the Bluetooth dongle dangling at the back of our amplifier seem strangely inadequate.

If audio is your thing, we had a look at some fundamentals of digital audio as part of our Know Audio series.

How The BBC (Still) Sends Audio To Transmitter Sites

September 13, 2022 by Jenny List 25 Comments

Running a radio station is, on the face of it, a straightforward technical challenge. Build a studio, hook it up to a transmitter, and you’re good to go. But what happens when your station is not a single Rebel Radio-style hilltop installation, but a national chain of transmitter sites fed from a variety of city-based studios? This is the problem facing the BBC with their national UK FM transmitter chain, and since the 1980s it has been fed by a series of NICAM digital data streams. We mentioned back in 2016 how the ageing equipment had been replaced with a modern FPGA-based implementation without any listeners noticing, and now thanks to [Matt Millman], we have a chance to see a teardown of the original 1980s units. The tech is relatively easy to understand from a 2020s perspective, but it still contains a few surprises.

In each studio or transmitter site would have been a 19″ rack containing one of these units — a card frame with a collection of encoder or decoder cards. These are all custom-made by the BBC’s engineering department to a very high standard, and use period parts such as the familiar Z80 microprocessor and some Philips digital audio chips, which followers of high-end consumer audio may recognize. As you’d expect for a mission critical device, many of the functions are duplicated for redundancy, with their outputs compared to give warning of failures.

The surprise comes in the NICAM encoder and decoder — it’s a custom LSI chip made exclusively for the BBC. This indicates the budget available to the national broadcaster, and given that these units have in some cases been working for over 35 years, we’re guessing that the license payers got their money’s worth.

You can read about the original switch-over in 2016, and a little more about NICAM, too.