Making A Phono Preamp For A First Electronics Project

Nearly everyone’s first electronic project is something that blinks a LED. There are a million ways to go about this ‘Hello World’ project of electronic design; 555 timers, microcontrollers, or maybe even discrete components if you’re really cool. When [miceuz] was asked by a friend to help with his first electronic project he eschewed the usual blinking LED project and taught him how to build something he actually needed: a phono preamp for an old turntable.

Back in the day when vinyl was king, albums needed to be mastered to play on a record player. The mastering process cuts some of the bass and increases the treble. When the record is played, this process needs to be reversed. It’s a preamp that does this job by attenuating the high frequency sounds and boosting the thumping bass.

[miceuz] found a nice DIY RIAA preamp  project and found a nice little op amp  somewhere in his parts bin. After laying out the circuit, [miceuz] etched a few boards and taught his friend how to solder SMD components.

Of course the project didn’t work the first time around, but after poking around with a meter and checking out the old turntable, the preamp came to life with the clang of chords from an old record. If you’d like to build your own, you can get the files from [miceuz]’s git.

Edison Cylinder Recordings Need More Cowbell

bruderhofer2-1

[Norman] spent three years developing and building his own Edison cylinder phonograph with electric pickup. We’re glad he did, and that he shared it with the world because the product is a thing of beauty. Every part is clean and precise with plenty of room for adjustments to accommodate differences in media. He’s reused the head from a VCR and attached it to a CNC machined polypropylene mandrel. The needle is interfaced with the cylinder via a delicate passively driven carriage. This consists of an aluminum rod with the cartridge at one end, and two wheels at the other. The wheels travel along a precision rod, propelled by the needle tracking the groove in the wax. Wonderful!

We’ve embedded a video of the device playing a recording of Sousa’s El Capitan from the late 19th century. Although familiar with these cylinder recordings, we were surprised by how little recording space there is available on one. Continue reading “Edison Cylinder Recordings Need More Cowbell”