Do you talk to your alarm clock? I do. I was recently in a hotel room, woke up in the middle of the night and said, “Computer. What time is it?” Since my Amazon Echo (which responds to the name Computer) was at home, I was greeted with silence. Isn’t the future great?
Of course, there have been a variety of talking clocks over the years. You used to be able to call a phone number and a voice would tell you the time. But how old do you think the talking clock really is? Would you guess that this year is the 140th anniversary of the world’s first talking clock? In fact, it doesn’t just hold the talking clock record. The experimental talking clock Frank Lambert made is also the oldest surviving recording that can be still be played back on its original device.
In 1878, the phonograph had just been invented and scratched out sounds on a piece of tin foil. Lambert realized this wouldn’t hold up to multiple playbacks and set out to find a more robust recording medium. What he ended up building was a clock that would announce the time using lead to record the speech instead of tin foil.
Continue reading “Talking Clock? That’s Nothing New”
You probably learned in school that Thomas Edison was the first human voice recorded, reciting Mary Had a Little Lamb. As it turns out though, that’s not strictly true. Edison might have been the first person to play his voice back, but he wasn’t the first to deliberately record. That honor goes to a French inventor named Édouard-Léon Scott de Martinville. He wanted to study sound and created the phonautograph — a device which visualized sound on soot-covered paper. They were not made to be played back, but the information is there. These recordings were made around 1860. There’s a 9-part video series about how the recordings were made — and more interestingly — how they were played back using modern technology. Part 1 appears below.
We say around 1860 because there were some early recordings starting around 1857 that haven’t been recovered. Eventually, the recordings would have a tuning fork sound which allows modern playback since the known signal can estimate the speed of the hand-cranked cylinder. The date of the first recovered recording was today, April 9th, 158 years ago.
Continue reading “Who Made the First Human Audio Recordings? Edison? Not so Fast!”
The 20th century saw some amazing technological developments. We went from airplanes to the moon. We went from slide rules to digital computers. Crank telephones to cell phones. But two of the most amazing feats of that era were ones that non-technical people probably hardly think about. The transformation of radio and TV from mono and black and white, to stereo and color. What was interesting about both of these is that engineers managed to find a way to push the new better result into the same form as the old version and — this is the amazing part — do it in such a way that the old technology still worked. Maybe it is the rate that new technology moves today, but we aren’t doing that today. Digital TV required all-new everything: transmitters, receivers, frequencies, and recording gear. Good luck trying to play the latest video game on your 25-year-old PC.
It is hard to remember when stores were full of all sorts of audio and video media. We’ve noticed that all forms of media are starting to vanish. Everything audio and video are all streamed or downloaded these days. Records, 8-tracks, cassettes, and even CDs and DVDs are vanishing. However, vinyl records have made a come back in the last few years for their novelty or nostalgic value.
Continue reading “Retrotechtacular: Stereo Records”
[Amanda Ghassaei] has created an awesome hack for making your own vinyl records using a laser cutter from an MP3 file. Her excellent hack uses a Processing sketch that converts a digital audio file into a vector graphics file, which is then burned onto vinyl using a laser cutter. We saw a demo of this at the FabLab11 conference, and it’s an impressive hack.
One of the best parts of her write up are the details of how she arrived at the appropriate processing settings to get the record sounding as good as possible, but still be cuttable. It’s an object lesson in how you iterate on a project, trying different approaches and settings until you find the one that works. She also decided to take it a few steps further, cutting records on paper and wood for the ultimate eco-friendly record collection.
Audiophiles should avoid this technique though. Due to limitations in the resolution of the laser cutter, [Amanda] ended up having to reduce the bandwidth of the audio signal to 4.5Khz and use a 5-bit sampling depth. That translates to a rather tinny-sounding record. Vinyl record snobs can breathe easy: this isn’t going to replace their beloved white-hot stampers. For the rest of us, there are always records etched into tortillas.
Continue reading “Laser Cut Your Own Vinyl Records”
Hackaday Prize judge [Ben Krasnow] has been busy lately. He’s put his scanning electron microscope (SEM) to work creating an animation of a phonograph needle playing a record. (YouTube link) This is the same 80’s SEM [Ben] hacked back in November. Unfortunately, [Ben’s] JSM-T200 isn’t quite large enough to hold an entire 12″ LP, so he had to cut a small section of a record out. The vinyl mods weren’t done there though. SEMs need a conductive surface for imaging. Vinyl is an insulator. [Ben] dealt with this by using his vacuum chamber to evaporate a thin layer of silver on the vinyl.
Just imaging the record wouldn’t be enough; [Ben] wanted an animation of a needle traveling through the record grove. He tore apart an old phonograph needle and installed it in on a copper wire in the SEM. Thanks to the dual stage setup of the JSM-T200, [Ben] was able to move the record-chip and needle independently. He could then move the record underneath the needle as if it were actually playing. [Ben] used his oscilloscope to record 60 frames, each spaced 50 microns apart. He used octave to process the data, and wound up with the awesome GIF animation you see on the left.
[Ben] wasn’t done though. He checked out a few other recording formats, including CD and DVD optical media, and capacitance electronic disc, an obscure format from RCA which failed miserably in the market. The toughest challenge [Ben] faced was imaging the CD media. The familiar pits of a CD are stored on a thin aluminum layer sandwiched between the lacquer label and the plastic disc. He tried dissolving the plastic with chemicals, but enough plastic was left behind to distort the image. The solution turned out to be double-sided tape. Sticking some tape down on the CD and peeling it off cleanly removed the aluminum, and provided a sturdy substrate with which to mount the sample in the SEM.
We’re curious if stereo audio data can be extracted from the SEM images. [Oona] managed to do this with a mono recording from a toy robot. Who’s going to be the first one to break out the image analysis software and capture some audio from [Ben’s] images?
Continue reading “Phonographs Through The Eye Of An Electron Microscope”
[smellsofbikes] recently came into possession of a 1970’s “stereo radio phonograph” cabinet consisting of a vinyl record player, AM and FM radio, and eight track tape player. The radio worked, the turntable didn’t sound too nice, and the tape player didn’t work at all. A new needle fixed the turntable, but the eight-track was in bad shape. So he replaced the tape player with a BeagleBoneBlack which plays streaming internet radio.
Hopefully, this fix is temporary, since he has carefully disconnected the tape player connections in the hope of fixing it soon. The swap out involved a fair bit of engineering, so he’s split his build log into several bite sized chunks. The first step was to set up the BBB, upgrade it and add in all the network and audio related stuff. Audio on the BBB is available only via the HDMI port, but [smellsofbikes] had a USB soundcard handy, so the next step was setting that up. He installed mpg321 – the command line mp3 player and set it up to play music streaming from somafm. Next up was getting some scripts and programs to run automatically during system bootup. The final part of the setup was adding a WiFi router as a repeater connected to the BBB via an ethernet cable. He could have used a tiny WiFi USB dongle, but he already had the router lying around, and he wanted to dedicate USB to audio functions alone, and use the Ethernet port for Internet.
He then worked on identifying the wires that go from the tape player to the amplifier, spliced them, and hooked them up to the audio sound card on the BBB. With this done, the upgrade was more or less complete – the system played streaming music and stations could be switched remotely (via SSH to BBB). [smellsofbikes] reckoned it would be nice to use the existing controls in the phonograph cabinet to control the internet streaming music, instead of controlling it via a remote computer. The cabinet had 4 indicator lamps that indicated which track was being played and a button to switch between tracks. He removed the old indicator panel and put in a fresh PCB, designed in KiCad and cut on his LPKF circuit board plotter. An aluminum knob machined out of hex bar-stock works as the new track change button. At this point, he called it a wrap. The BBB and Asus router go inside the cabinet, and the old (non-functional) tape player is put in place. Quite an interesting build, and we look forward to when he actually gets the tape player working. [Alan Martin], aka “The Most Interesting Engineer In The World” has told him that “it is a moral imperative that you repair the eight-track and get it working”. [Alan] has promised to send [smellsofbikes] a suitcase full of brand new, still in their plastic wrappers, eight-track tapes when he gets it working.
If you were a child of the 80’s or early 90’s you probably remember Magic Mike. He went by many names, but he always said the same thing “I am the atomic powered robot. Please give my best wishes to everybody!” [Oona’s] version of Mike had been malfunctioning for a few years. He’d stopped talking! She decided he needed more input, so she disassembled Mike to reveal the flesh colored plastic box in the center of his chest. This talkbox was used as a sound module in several toys. Before the days of cheap digital playback devices, sounds were recorded in a decidedly analog fashion. [Oona] found that Mike’s voice and sound effects were recorded on a tiny phonograph record in his chest. The phonograph was spun up by an electric motor, but the playback and amplification system was all mechanical, consisting of a needle coupled to a small plastic loudspeaker. The system was very similar to the early phonograph designs.
Mike’s record contained two interwoven spiral tracks. Interwoven tracks is a technique that has been used before, albeit rarely on commercial albums. One track contained Mike’s voice, the other the sound of his laser gun. The track to be played would be chosen at random depending upon where the needle and record stopped after the previous play. The record completely sidetracked [Oona’s] repair work. She decided to try to read the record optically. She started with a high resolution image (image link) of the record, and wrote some Perl code to interpolate a spiral around the grooves. The result was rather noisy, and contained quite a bit of crosstalk. [Oona] tried again with laser illumination using a Lego train set. Unfortunately the Lego train / laser system wasn’t smooth enough to get a good image. In the end she used a bit of Gimp magic and was able to pull better audio from her original image. We never did find out if she put poor Mike back together though.
Continue reading “Atomic Powered Robots and Records Played With Optics”