Some of us are guilty of picking up questionable hardware from garage sales, fleamarkets, and well-meaning relatives. There is a balance between turning down a good investment and hoarding, and if we figure out how to tell the difference you will be the first to know. [Clem Mayer] may start on the side of unwise acquisition, but he pushes a broken fetal detector into the realm of awesome by converting it to an analog synthesizer, born to headline at an Eastern European dance party.
He starts with a basic teardown, and we get to see how old hardware was serviceable with only two standard screws. It is a good thing too, because the nickel-cadmium batteries are older than some of you and they are in need of replacement. New nickel-metal hydride batteries got it up and running but [Clem] does not have a baby bump so its functionality turned to Pink Floyd era synthesizer circuit bending. Circuit bending involves modifying a circuit for sound it was not intended to make.
Continue reading “A Baby Named DJ”
Have you ever wanted to build a high quality audio crossover and amplifier? [Rouslan] has put a lot of thought into making his dual amplifier studio monitor both high quality and simple to build.
With a concise schematic, a meaningful block diagram, and simulation results to boot, his well-written post has everything you need to build self-powered bi-amped speakers based on the LM4766 from Texas Instruments. It is great to see simulations which verify the functionality of the circuit, this can go a long way when working with complicated analog filters and audio circuitry. For those of you who do not have access to PSPICE (an expensive professional simulation tool), [Rouslan] uses LTspice from Linear Technology. TINA-TI from Texas Instruments is another great free alternative.
Additionally, [Rouslan] goes over the typical issues one has with a bi-amplifier studio monitor, such as phase misalignment and turn-on pop, and then provides a solution. Note that his project is powered by 20VAC, which requires an external transformer to convert the 120VAC in the wall to 20VAC. Be careful with high voltages! In the future, adding a high quality voltage regulator will most likely increase the performance.
His post finishes up with a very clean circuit board, which he ordered from OSH Park. With such a complete design, there is nothing keeping you from building your own. Go out and put that old speaker sitting in your basement to good use!
If you don’t have an old speaker sitting around, check out these very cool DIY speakers.
Here’s the scenario: You’ve got the rage to play som CoD (we’re more GTA fans but whatever) but the monitor you’re going to play on has no speakers. You can get a crystal clear image using HDMI, but getting sound is a different matter. What’s the fix? Crack open your PS3 and solder on some audio connectors.
[Paul] knew there is a special cable that breaks out analog audio. Like original Xbox hacking of ages past, there is now plenty of information online about the internals of these machines. He grabbed a copy of the A/V pinout and found the analog audio pins. After soldering on this pair of RCA cables he
cut savaged a hole in the case and put the console back together. The machine he’s working with is a salvaged unit with no Blu-ray drive — he links to his past posts on the repair process. You may be thinking what good is it without an optical drive? Remember, this is the beginning of the Internet age… everything is downloadable.