Knock-Off AirPods Merged into Bluetooth Receiver

Whether or not you personally like the concept of the AirPod Bluetooth headphones is irrelevant, as an Apple product one thing is certain: all the cool kids want them. That also means that plenty of overseas manufacturers are pumping out janky clones for a fraction of the price for those who are more about the Apple look than the Apple price tag. Are they any good? No, of course not. But that doesn’t mean you can’t do something interesting with them.

[Igor Kromin] took apart a pair of fake AirPods and was predictably underwhelmed. So much so that he didn’t …read more

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Listening To Mains Power

There’s a lot you can tell by looking at the waveform of your mains power. There are harmonics, transient changes, and periodic fluctuations that are correlated to the demand on the grid itself. Frequency shifts will tell you how fast or slow your clocks are running, and someone probably has a poorly isolated power line communication thing somewhere in your neighborhood. There’s a lot you can learn by looking at the waveform coming out of your outlets, but how do you tap into that? [David] is doing it with a PC sound card and some really interesting hardware.

The Grid …read more

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Cross-Correlation Makes Quick Work Of Ads

Once relegated to the proverbial Linux loving Firefox user, ad blocking has moved into public view among increased awareness of privacy and the mechanisms of advertising on the internet. At the annual family gathering, when That Relative asks how to setup their new laptop, we struggle through a dissertation on the value of ad blockers and convince them to install one. But what about mediums besides the internet? Decades ago Tivo gave us one button to jump through recorded TV. How about the radio? If available, satellite radio may be free of The Hated Advertisement. But terrestrial radio and online …read more

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3 Key Mobile Enterprise Threats in 2018

As attackers constantly innovate new exploitation and evasion techniques, enterprise security teams are having to stay ahead of a host of emerging threats. Often, these threats have been encountered in other enterprises, and shared knowledge of these t… Continue reading 3 Key Mobile Enterprise Threats in 2018→

The VU Meter and How It Got That Way

Given its appearance in one form or another in all but the cheapest audio gear produced in the last 70 years or so, you’d be forgiven for thinking that the ubiquitous VU meter is just one of those electronic add-ons that’s more a result of marketing than engineering. After all, the seemingly arbitrary scale and the vague “volume units” label makes it seem like something a manufacturer would slap on a device just to make it look good. And while that no doubt happens, it turns out that the concept of a VU meter and its execution has some serious …read more

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Finding The Linear In A Laser

If your path has taken you through any work with hi-fi audio, you will be aware of the effects of distortion on sound quality. The tiniest non-linearity in a component can ruin the result, and people who work at the extreme end of the hi-fi spectrum will go to impossible lengths to chase the tiniest percentages of distortion that no human could possibly hear.

[Monta Elkins] has a Boldport kit, the Lite2Sound, which as its name suggests translates a light level to an audio signal. Given a laser diode and a source of country music from his Amazon Echo then, …read more

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A Stereo Tube Amp For Less Than $5

Many of us have aspirations of owning a tube amp. Regardless of the debate on whether or not tube audio is nicer to listen to, or even if you can hear the difference at all, they’re gorgeous to look at. However, the price of buying one to find out if it floats your boat is often too high to justify a purchase.

[The Post Apocalyptic Inventor] has built a stereo tube amplifier in the style of the Fallout video games. The idea came when he realised that the TK 125 tape recorder manufactured by Grundig was still using tube audio …read more

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The Hot and Cold of Balanced Audio

A few summers of my misspent youth found me working at an outdoor concert venue on the local crew. The local crew helps the show’s technicians — don’t call them roadies; they hate that — put up the show. You unpack the trucks, put up the lights, fly the sound system, help run the show, and put it all back in the trucks at the end. It was grueling work, but a lot of fun, and I got to meet people with names like “Mister Dog Vomit.”

One of the things I most remember about the load-in process was running …read more

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