A Guide To Audio Amps For Radio Builders

For hams who build their own radios, mastering the black art of radio frequency electronics is a necessary first step to getting on the air. But if voice transmissions are a goal, some level of mastery of the audio frequency side of the equation is needed as well. If your signal is clipped and distorted, the ham on the other side will have trouble hearing you, and if your receive audio is poor, good luck digging a weak signal out of the weeds.

Hams often give short shrift to the audio in their homebrew transceivers, and [Vasily Ivanenko] wants to …read more

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Dead Simple Ultrasonic Data Communication

Some of the best hacks are the ones which seem perfectly obvious in hindsight; a solution to the problem that’s so elegant, you wonder how it never occurred to you before. Of course we also love the hacks that are so complex your eyes start to water, but it’s nice to have a balance. This one, sent in by [Eduardo Zola] is definitely in the former group.

In the video after the break, [Eduardo] demonstrates his extremely simple setup for using ultrasonic transducers for one-way data communication. Powered by a pair of Arduinos and using transducers salvaged from the extremely …read more

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DIY Mini-Amp Goes to Eleven

On the day mini-amps were invented, electric guitar players the world over rejoiced.  No longer would they be house-bound when jamming out on their favourite guitar. It is a doubly wondrous day indeed when an electric guitar-inclined maker realizes they can make their own.

[Frank Olson Music] took apart an old pair of headphones and salvaged the speakers — perhaps intending to replicate a vintage sound — and set them aside. Relying on the incisive application of an X-Acto knife, [Olson] made swift work cutting some basswood planks into pieces of the amp before gluing them together — sizing it …read more

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Theremin in Detail

[Keystone Science] recently posted a video about building a theremin — you know, the instrument that makes those strange whistles when you move your hands around it. The circuit is pretty simple (and borrowed) but we liked the way the video explains the theory and even dives into some of the math behind resonant frequencies.

The circuit uses two FETs for the oscillators. An LM386 amplifier (a Hackaday favorite) drives a speaker so you can use the instrument without external equipment. The initial build is on a breadboard, but the final build is on a PCB and has a case. …read more

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Multifunction Raspberry Pi Chiptune Player

General Instrument’s AY-3-8910 is a chip associated with video game music and is became popular with arcade games and pinball machines. The chip tunes produced by this IC are iconic and are reminiscent of a great era for electronics. [Deater] has done an amazing job at creating a harmony between the old and new with his Raspberry Pi AY-3-8910 project.

[Deater] already showed us an earlier version of the project on a breadboard however after having made some PCBs and an enclosure the result is even more impressive. The system consists of not one but two AY-3-8910 for stereo sound …read more

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“What is My Purpose?” You Amplify and Display Signals.

[Andy_Fuentes22] likes to stream music, but is (understandably) underwhelmed by the sound that comes out of his phone. He wanted to build something that not only looks good, but sounds good. Something that could stream music through a Chromecast or a Raspi, but also take auxiliary input. Something awesome, like the Junkbots Sound System.

The ‘bots, named LR-E (Larry) and R8-CHL (Rachel), aren’t just cool pieces of art. They’re both dead-bug-walking bots with an LM386-based amplifier circuit and an AN6884-based VU meter in their transparent, industrial relay bodies. LR-E is the left channel, and his lovely wife is the right …read more

Continue reading “What is My Purpose?” You Amplify and Display Signals.

“What is My Purpose?” You Amplify and Display Signals.

[Andy_Fuentes22] likes to stream music, but is (understandably) underwhelmed by the sound that comes out of his phone. He wanted to build something that not only looks good, but sounds good. Something that could stream music through a Chromecast or a Raspi, but also take auxiliary input. Something awesome, like the Junkbots Sound System.

The ‘bots, named LR-E (Larry) and R8-CHL (Rachel), aren’t just cool pieces of art. They’re both dead-bug-walking bots with an LM386-based amplifier circuit and an AN6884-based VU meter in their transparent, industrial relay bodies. LR-E is the left channel, and his lovely wife is the right …read more

Continue reading “What is My Purpose?” You Amplify and Display Signals.

You Can Have My LM386s When You Pry Them From My Cold Dead Hands

Everyone has a chip-of-shame: it’s the part that you know is suboptimal but you keep using it anyway because it just works well enough. Maybe it’s not what you would put into a design that you’re building more than a couple of, but for a quick and dirty lashup, it’s just the ticket. For Hackaday’s [Adam Fabio], that chip is the TIP120 transistor. Truth be told, we have more than one chip of shame, but for audio amplification purposes, it’s the LM386.

The LM386 is an old design, and requires a few supporting passive components to get its best performance, …read more

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Fail of the Week: The Accidental FM Radio

[B Arnold] is hearing voices and needs help from the Hackaday community. But before any of you armchair psychiatrists run off to WebMD, rest assured that [B Arnold] suffers not from schizophrenia but rather has an RF coupling problem.

The project (which isn’t posted yet) is an attempt to turn a C.H.I.P into an Amazon Echo, for which [B Arnold] needed an audio amplifier. Turning to the junk bin, he unearthed an LM386, that venerable power amp chip that first appeared in the mid-70s. Dead simple and able to run off a 9-volt battery, the LM386 that has found its …read more

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Raspberry Pi Chiptune Player Rocks a Sound Chip from the 80’s

Sometimes it’s worth doing something in an inefficient way. For example, it might be worth it in order to learn something new, or just to use a particular part. [Deater] did just that with the Raspberry Pi AY-3-8910 Chiptune Player (with LED visualizers!)

The venerable General Instrument AY-3-8910 series sound chips were common in older hardware like home computers and game consoles as well as sound cards for the Apple II family. They were capable of generating three channels of square waves with various effects. Developers eventually squeezed every little bit of performance out with clever hacks. The Raspberry Pi …read more

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