The biggest and best audiophile projects are usually huge tube amps, monstrous speaker cab builds, or something else equally impressive. It doesn’t always have to be that way, though, as [lowderd] demonstrates with a tiny DIY USB DAC build that turns a USB port into a headphone output.
In the Bad Old Days™ putting a DAC on a USB bus would require some rather fancy hardware and a good amount of skill. These days, you can just buy a single chip USB stereo DAC that still has very good specs. [lowderd] used the TI PCM2707 USB DAC, a chip that identifies as a USB Audio Class 1.0 device, so no drivers are needed for it to work in either Windows or OS X.
The circuit fits on a tiny PCB with a USB port on one side, a headphone jack on the other, and the chip and all related components in between. There are some pins on the chip that allow for volume, play/pause. and skip, but these pins were left unconnected for sake of simplicity.
The board was fabbed up at OSH Park, and the second revision of the case laser cut out of bamboo and acrylic by Ponoko. It’s a great looking little box, and something that fits right inside [lowderd]’s headphone case.
Not wanting to wait for Apple to step up their game and complete their purchase of Beats headphones, [Carnivore] decided he wanted his own pair of Apple-compatible Beats cans with Bluetooth. He created something that will probably be for sale in the Apple store come Christmas: a pair of Beats Pro headphones with Bluetooth and a Lightning connector for charging.
[Carnivore] liked the sound of his Beats Pro headphones but hated the wires. After disassembling the headphones, he carefully rewired the speakers with smaller gauge wire, added a small Bluetooth module and battery, and sealed everything back up.
There are a few interesting bits to this build – by getting rid of all external wires, [Carnivore] was left with a few holes in the headphones. These were a perfect place to add a 3D printed mount for the power button and the Lightning adapter taken from an Apple Lightning extension connector.
Thanks [Tony] for the tip!
Noise-Cancelling Headphones actively cancel external sounds so the listener can hear their media without distraction. They do this by taking external sound waves from an on-board microphone, inverting the audio signal and mixing that with the media audio. The outside sounds and their inverses cancel each other out before reaching the listener’s ears. There is one downside to these types of noise-cancelling headphones, they are very expensive.
[Mike] works in a wood shop and didn’t want to pony up the hundreds of dollars it would cost for a pair of noise-cancelling headphones, let alone having such an expensive electronic device in a dusty workshop. The solution? Make some headphones that will block out the noise but still allow the comfortable listening of music. This project is simple but effective; inexpensive headphones taken apart and installed in a pair of Industrial Ear Muffs. If you’d like to make your own, [Mike] gives step by step on the above link.
Continue reading “Block Noise, Listen To Music”
It’s hard being a kid sometimes. [Young] likes his music, but his dad is an overnight trucker. With his dad sleeping during the day, [Young] has to keep the volume down to a reasonable level. He could have bought some commercial headphones, but he wanted something a bit more customized. Rather than give up on his tunes, he built a pair of headphones with an internal tube preamp amplifier. [German language link — Google translate doesn’t want to work with this one but Chrome’s translate feature works].
Two 1SH24B preamp tubes feed two LM386 amplifier chips, creating a hybrid amplifier. The 1SH24B tubes are designed to work on battery voltage, so a step up circuit wasn’t necessary. However, [Young] still needed to provide an 8 cell battery pack to run his amp. Speakers were a 3 way coaxial of [Young’s] own design. He built the headphone frame using candy tins and cups from commercial headphones. A final touch was a window so everyone can see all that vacuum state goodness. Considering that [Young] is only 16, we’re looking for some great things from him in the future.
If you don’t want to strap the tubes to your skull there are other options. But you have to admit it makes for a cool look. Starbucks here we come.
[Mansour] was disappointed to find out that his Bose QC15 headphones had a dead right channel. These headphones have active noise cancelling, which uses a microphone to capture ambient noise and digital signal processing to insert an out of phase signal. Since they’re quite expensive, [Mansour] was determined to resurrect them.
First, he determined that the right speaker had died, so he found a replacement on eBay. These were designed for a different set of headphones, but matched the impedance of the original Bose part. After replacing the driver, it seemed that the repair was a failure. The sound cancelling wasn’t working, and a the playback was high-pitched. As a last attempt, he potted the speaker with glue, to match the original construction. Much to his surprise, this worked.
The problem was that the new driver didn’t have sufficient sound isolation from the microphone, which is meant to pick up passive noise. This feedback likely caused issues with the noise cancelling DSP. A little glue meant a $20 fix for a $400 pair of headphones.
We’ve come to expect quite a lot of convenience from our technology, to the point where repeatedly plugging in a device for recharging can seem tedious. Hackaday regular [Valentin Ameres] decided to ditch the plugs and built his own wireless headphone charger. We’ve seen [Valentin’s] work before, and one thing’s for certain: this guy loves his laser cutter. And he should, considering it’s churned out key components for a gorgeous Arc Reactor replica and his Airsoft Turret. [Valentin] fired it up yet again to carve the charging stand out of acrylic, then used a small torch and the edge of a table to bend the stand into shape.
He sourced the needed coils online and soldered the receiving coil to a spare miniUSB plug. These components are glued onto a laser-cut acrylic attachment, which fits against the side of the headphone and is held in place by plugging directly into the earpiece’s miniUSB jack. The headphones rest on the laser-cut charging stand, which has an extrusion of acrylic on one side that holds the emitter coil in position against the receiver coil. [Valentin] also added a simple momentary switch at the top of the stand to activate both the emitter coil and a status LED when pressed by the headphones.
Stick around for a video of the build below, and check out some other headphone hacks, like adding a Bluetooth upgrade or making a custom pair out of construction earmuffs.
Continue reading “Custom Wireless Headphone Charging Station”
When work on an engine control circuit [Scott] found himself in need of a way to compare the performance of two control circuits at once. The hobby quality oscilloscope he owns wasn’t up to the task. After thinking about it for a bit he ended up using his ears as the oscilloscope.
The signals he was measuring are well suited for the challenge as they fell within the human range of hearing. He used some wire wrapped around each of the three conductors on the jack of his headphones in order to connect them to a breadboard. Then he simply connected each channel to one of the motor driver circuits, and connected the common ground. Listening to the intonation of the pitches in each ear he was literally able to tune them up.
If he had been looking for a specific frequency he could have used his sound card to take and analyze a sample. But balance was what he needed here and you must admit that this was an easy and clever way to get it!