Most audio tube amps we see use common tubes – usually a 12AX7 for the preamp and one of the more common power tubes such as an EL34.[Daniel], on the other hand, decided to build his own audio tube amp with a 13EM7, a tube originally used for a television’s vertical oscillator. The resulting project is a wonderful stereo amp that sounds really good, to boot.
[Daniel] picked up the idea of using a 13EM7 tube from [Fred Nachbaur]’s MiniBlok SET amplifier. This very tiny 1-watt tube amplifier uses a single tube originally designed for use in old, old televisions. The secret behind this build is the fact this tube is actually two triodes in one package; one side of the 13ME7 has tons of gain but not much power, making it perfect for a preamp. The other side has a lot of power, useful for delivering two watts of power into a speaker.
After [Daniel] etched a few boards for his amp, he milled out a piece of wood for the chassis. When everything was mounted he had an awesome looking stereo amplifier that also sounds great.
With the help of a microcontroller, a few strings of GE Color Effect Christmas lights can be easily turned into a fully programmable LED strip, or if you are so inclined, a huge RGB LED display. [Hubbe] had a few strings of these Color Effect Christmas lights, but didn’t want to spend the time arranging his light strings in an array simply to get a programmable display. His solution to this problem – the Chaos Display – turns strings of Christmas lights randomly thrown on a tree into a fully programmable display capable of displaying text and images.
[Hubbe] was inspired by QC Co-Lab’s light wall powered by GE Color Effect lights. Having a huge RGB LED display is very cool, but requires building a frame for each of the Christmas light pixels. [Hubbe] had a different idea – just throw the lights on a tree and use a web cam to figure out where each Christmas light is on the display.
The actual build consists of six strings of Color Effect lights. After throwing them on the tree, [Hubbe] set his phone on a tripod to record an image for each individual light. With some computing power, he was able to create a virtual display made of tangled strings of Christmas lights.
You can see a video of [Hubbe]’s work after the break.
Continue reading “Displaying text on random strings of Christmas lights”
[Bunnie Huang], creator of the Chumby and artisan of chips and electrons, is building his own completely open source laptop. It’s called the Novena, and is powered by a quad-core ARM CPU, it’s got enough bells and whistles to make any hacker happy including an on-board FPGA, dual Ethernet ports, and enough GPIO pins to do some crazy, crazy stuff.
[Bunnie]’s laptop is an attempt to create a completely open-source laptop capable of some light code development, and web browsing. Every single chip on [Bunnie]’s laptop has a datasheet available (without requiring an NDA, unlike the Raspberry Pi), meaning this laptop might be the beginning of a completely open source laptop.
Officially, this laptop is a one-off project made just for [Bunnie]. He’ll be spending the next few months validating all features on the board and making a proper case. [Bunnie] says a few people may be interested in their own Novena (smart one, that guy), so he might consider a Kickstarter campaign in a few months. Don’t expect it to be cheap, but if you’d like to try your hand at making your own, all the files are up on the Novena wiki.