Reproducing A Reproducer: Servicing A Cylinder Phonograph In The Year 2021

[Jan Derogee] pulled out his phonograph the other day to hear the 100+ year old wax cylinder warble of “It’s a Long Way to Tipperary”, but couldn’t locate the reproducer — this is the small circular bit that holds the stylus and transfers the groove-driven vibrations to the center of a thin diaphragm, which vibrates into the sound horn. It’s easily the most important part of a cylinder phonograph. What do you do when you lose your reproducer? You could search ebay for a replacement, but that wouldn’t be nearly as fun as reproducing your reproducer yourself.

Traditionally, diaphragms were made from mica or celluloid, and the Edison disk phonograph used seven layers of shellac-soaked rice paper. Reproducers typically have a Dagwood sandwich of gaskets surrounding the membrane, but they don’t have to be so convoluted to work — a single strong membrane will do just fine. Just ask [Jan], who made a new reproducer with a 3D-printed case, a hand-pulled glass stylus, and a disposable aluminum foil pan for the diaphragm.

It’s difficult for us to say which part looks more fun — stretching the glass shard over a gas kitchen stove with the flame focused by a stack of wrench sockets, or cutting up a bicycle inner tube and using a car jack to press the aluminum into shape against a 3D-printed mold. The whole video is awesome and you can check it out after the break.

As [Jan] notes in the video and on the project site, the glass stylus should really be made from borosilicate because it’s harder than regular soda lime glass (that’s why they often make vaccine vials out of it). Regular glass will work and takes much less time and gas to reach the pull-able stage, so that’s what [Jan] used in the video, but it will wear out much more quickly. Fortunately, this was a temporary solution, because as soon as [Jan] made a replacement, the missing reproducer showed up.

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Tunes You Can Eat

This week retro-gadget collector and video blogger [Techmoan] featured perhaps the most delicious audio recording format that we know of — a chocolate gramophone record. (Video, embedded below.) Compared to his typical media format explorations, the chocolate record is of quite recent vintage. He first heard of them back in 2015 when Tasmanian artist [Julia Drouhin] offered chocolate recordings as part of her art project. The one that [Techmoan] finally obtained was from a UK chocolatier who offers them with custom labelling and your choice of two songs. There are some pointers in the video about how to playback your chocolate disk without ruining it (use the lightest stylus tracking force as possible). These disks are recorded at 45 RPM on one side only, and are about the same size as a standard single. But being about five times thicker, they pack a lot more calories than your typical phonograph disk.

No reflection on the Tewkesbury Town Band, but this is probably the lowest fidelity recording media ever, but at least you can eat it when you’re done listening — label and all. We hope the Mission Impossible movie producers are paying attention so we can see the secret audio briefing being eaten instead of going up in smoke next film.

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Talking Clock? That’s Nothing New

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.

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Who Made The First Human Audio Recordings? Edison? Not So Fast!

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.

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Retrotechtacular: Stereo Records

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.

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Laser Cut Your Own Vinyl 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.

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Phonographs Through The Eye Of An Electron Microscope

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 imagingphono_anim_1. 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. 

pits[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?

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