[Dan Hemingson’s] been refining a design for building a tetrahedral ambisonic recording system. This is a set of four microphones used to record audio that can later be mixed down for a three-dimensional listening experience. His goal is an easy and inexpensive build while maintaining the highest fidelity standards possible. Lucky for us he’s made a set of extremely detailed build instructions you can use to make your own. In addition to the mounting bracket seen above he has also developed a pre-amp module that connects to the four mics; it’s part of the build instructions with schematic and board layout files available as well.
If you’re curious about tube amps but don’t have a firm enough knowledge base to dive right in you might want to try a kit. [Mark Houston] reviewed one such kit and we enjoyed reading about his experiences. It comes with everything you need save soldering tools, an enclosure, and the final connectors ([Mark] used RCA connectors). There is a full schematic available and the assembly instructions take you through tube matching and using that piece of copper coil you see in the picture to wind your own inductor. Consider trying this primer before you jump into building a single tube, multiple tube, or an amplifier of your own design.
[Bryan] sent in this old but excellent guitar cable hack. [J. Donald Tillman] managed to fit a fet based pre-amp inside the 1/4″ connector of a guitar cable. It’s phantom powered – so it’ll leach power from the sound board/mixer. I’m just impressed that he fit the thing inside there.
On a side note, This is the kind of crap that gives hackers a bad name. I hope the jerks behind it end up as Soylent Green.
Yesterday, I was standing on a tropical island off the coast of Belize. Vacation rocked with lots of SCUBA diving, spearfishing and snorkeling. I’m back home, shaking off the jet lag and clearing up my inbox. Thanks to [fabienne] for filling in and letting me unplug for a while!
[Darkrom] has set a new standard for Hack-A-Day readers… I haven’t seen it in person, but that looks like a legit Hack-A-Day tattoo.
[null] sent in a new use for a frequency generator, a spare car amp, a sub-woofer and a plastic coffee can – brass cartridge polishing.
[LoopyMind] sent in this Game Boy Advanced Movie Player IDE hack. It’s pretty much a direct CF to laptop drive cable with an external battery supply.
[Dingolishious] sent in a POE UPS/remote power control solution. Could be handy if you’re using many POE devices, or if you’re having power issues. He added an inexpensive remote power monitor/switch solution behind his UPS. It senses power outages and kicks out an email – and allows remote power cycling of his POE devices. Of course, if you’ve got a linux box behind the UPS, it can monitor the output from the UPS and send notifications.
[William] added a preamp stage to his iKEY usb recorder. looks like an interesting toy – it’ll record audio directly to a USB flash key. The pre-amp allows him to record in more challenging environments.
[Andrew] noted a simple mod to increase the deadly fire power of the ubiquitous airsoft pellet gun. It’s just a matter of reducing some extra space in the spring compression area.
Last but not least, [VIPER] modded his projector to use a 12v halogen headlight bulb. Not a bad idea – at one point I was pondering a 550 watt source four halogen as a possible replacement.