[Rogers Gomez] has posted up this hybrid tube based headphone amplifier over at DIY Audio. Being a fan of tube amplifiers, but wanting something with lower voltage and lower cost, he put together this little system out of spare parts he had lying around. He wanted it to have as few parts as possible and be able to power his 32 ohm Grado headphones.
He states that he'd built several YAHA amps, and a Szekeres Mosfet follower and was curious how they'd sound together. He was pleasantly surprised with the resulting quality.
There are less than 30 individual components involved in the project. The complete parts list and schematics are available from the site. He notes at the very end, to unplug your headphones when powering up as there is a surge that could damage them. That might be good to know at the beginning just in case you get eager to test it out.
Deogen is a small, self contained device for testing monitors. It was designed back in 2000 to reduce the amount of space and effort required to test monitors in a computer shop. The initial design used an AT90S1200 microcontroller to generate test patterns for the monitors. Being about the size of a portable CD player, it was much easier to take to any monitor and plug in for testing.
Version two of the device, pictured above, is much smaller, being about the width and height of a credit card. The depth is slightly larger than a 9 volt battery. Compared to the last vga test project we ran, this one is tiny. The unit boasts a decent set of features, such as; eight test patterns at four different resolutions, battery or DC power, and small form factor.
The processor of version two is an ATtiny2313 at 20MHz, and controls the H sync and V sync signals directly. The RGB is converted to analog using a resister network. The power circuit is custom made for low power consumption, though they note that a 78L05 equivalent unit could be used in its place.
The plans for the PCB and the software are available from their site. Head on over and check out some pictures of it in action.
[Scott] shot us a tip about some progress on hacking those creepy [Elvis] heads produced by Wowee. The head uses a flash cartridge to store all the data used for the motion/audio control. The cartridge uses NAND flash, so a quick solder job to an XD flash card reader yielded a useful dump of the memory cartridge - which happened to be fat32 formatted. There's still plenty of work to do, but it seems that it'll be trivial to replace the data with custom audio and motion commands.
Popular Mechanics contributor [Rob Sabin] has posted his experience building a pair of bookshelf speakers. He purchased a kit from North Creek Music Systems. It included the drivers, assembled crossovers, and pretty much anything that wasn't wood. He constructed the cabinets from MDF with a birch front a back. Something interesting we hadn't seen before: the instructions included stuffing the port with straws to "fine-tune the speaker's low-end bass limit". The article has plenty of pictures of the construction, but we would have enjoyed a little more info on the electrical side. Have any of you built a significant portion of your audio system? It's easy to spend a lot of money on audio components, so we can't chide someone for saving money by building their own, especially on something so subjective. Being true audiophiles, we personally use a cheetah blood coating on our braided CAT-5 speaker cables when auditioning new components.
[GonzoMPM-1] Has gutted an NES knock off called Super Joy III and crammed it inside of a light gun. Inspired by a daughter that loves duck hunt, he wanted to consolidate the package and make it more portable. He's managed to pull off some nice finish, it look almost professional in the picture above. The unit is powered by 3 AAA batteries in the handle. The game system works just fine, and he claims that the controls are actually more responsive now. The light gun works as well if you have a CRT television around.
You many notice that there is no cartridge slot. There really isn't a need for one in this mod. The Super Joy III comes equipped with 76 games on the board. He notes that he can make an external cart at some point, but may leave it off in favor of the compact design.
While he acknowledges that this is not a completely self contained gaming device, we feel it earns honorable mention for being cool.
USB NES controllers are old school these days, but [Jay] put together a nice new take on the project. He shoehorned a USB interface adapter, USB hub and a USB memory stick to store his collection of NES roms and emulators right on the controller. He even dug up a black USB cable to keep the original look of the controller. Now he can just plug in and load his game selection directly from the controller.
Today, [sprite_tm] let us in on one of his pet projects. This is an inexpensive portable game platform runs about $50 and happens to use an ARM CPU and a 320x240 color LCD. Because it's so cheap, he's been working on reverse engineering the thing and there's already a proof of concept homebrew version of Pong out for it. Update: Yeah, yeah - title's fixed.
The first video game every created is attributed to physicist William Higinbotham. Tennis for Two is played on an oscilloscope using two controllers. Each one has a knob that controls the trajectory and a button to hit the ball. The fine folks at Evil Mad Scientist Laboratories have recreated the game so you can play it on any oscilloscope. An ATmega168 is used to control everything. It takes user input from the paddles and outputs an the X and Y analog signals for the scope. An R-2R style DAC is used for the output stage which gives a 256x256 resolution. Everything is built on top of one of their business card sized project boards-which really shows how useful such a simple board can be. The source code is free and the write up includes plenty of detail. We'd love to see what modifications people come up with since the base game doesn't even have scoring. There's a video of EMSL's system embedded below.
The mod is not particularly complex. The Microvision 360's creator [PvP_LostKnight] only removed the working parts from the Xbox 360's case and mounted them to the back of the TV. A few of the inputs of the TV had to be moved and rewired, and a repurposed and painted tupperware container was added to cover the Xbox 360 parts. Unfortunately, [PvP_LostKnight] did not post a writeup, and even added "The wiring for this is horrible, I would not recommend anyone trying this."
Setting aside his recommendation for a moment, a few of the advantages to his design are improved airflow to the Xbox 360 and better space usage. What we'd like to see added more than anything is power integration, with a single button to turn on both and a single power source powering the TV and the Xbox. See the proof of concept video after the break, or more photos and comments at the read link.
If you've got an extra grand laying around, you can pre-order one of [nortd]'s touchkits. It features a unique custom made acrylic screen with a crap ton of IR LEDs embedded in it. An included IR camera provides the input and a projector (you get to supply your own) is used to light the surface. We mentioned this in our multitouch roundup and you can find a video of it embedded after the break.
A small group of enthusiasts have apparently been restoring and reprogramming the animatronic bands from the former Showbiz Pizza Place chain. Original engineer [Aaron Fechter] and car salesman/choreographer [Chris Thrash] have started performing modern pop songs with the bands and have a page where you can bid on new songs to perform. This feels like Billy Bass hacking on a much larger scale. The original machines were controlled by a four track reel, but now they're using a hard disk recorder. The trailer above is worth watching just for the rows of partially assembled bears performing on the factory floor.
The Netflix Player continues to gain in popularity. Roku has finally released the GPL code for their Netflix Player. Just today Forbes published that Roku would roll out a software update allowing it to stream from other online services. The diminutive device has no internal storage and just enough RAM to buffer the stream. Many have wondered how a Linux box is handling the DRM; this is purely a feature of the NXP PNX8935 processor being used. While waiting for the code, hackers have already popped the box open to see what's inside. We found [hokiokie7]'s photos of the internals on Roku's forum. The only really interesting thing we've seen so far is that the WiFi is on a daughter card that plugs into the USB. That should make it much easier to support other devices, if users ever manage to get into the system.
UPDATE: [mbailey] points out in the comments that he was able to telnet to the device.
[Gio] sent in this slick Class A headphone amp. An old CD-ROM case was gutted to hold the goods. The design is fairly simple. Cost can be kept fairly low although the capacitors can add up if you're a fanatic about quality. If you've ever lost any of your headphone gear to sticky fingers, you know that having it blending in to the background can be a great feature.
You can make pretty much anything a speaker by vibrating it. Japanese engineer, [Keiji Koga], has been working for many years to perfect his plant based sound transmission system. The voice coil is at the bottom of the plant container and transfers sound up the stalk to the leaves. It's and interesting idea, but we can't imagine it sounds much better than vibrating a rigid surface.
