Building An Audio Box Out Of Thrown Away Boards

The last time [Mark] was at the scrap yard, he managed to find the analogue input and output cards of an old Akai DR8 studio hard drive recorder. These cards offered great possibilities (8 ADC inputs, 12 DAC outputs) so he repaired them and made a whole audio system out of them.

The repair only involved changing a couple of low dropout regulators. Afterwards, [Mark] interfaced one of his CPLD development boards so he could produce some sine waves and digitize signals generated from a PC based audio test unit. He then made the frame shown in the picture above and switched to an Altera Cyclone IV FPGA. To complete his system, he designed a small board to attach a VGA screen,  and another to use the nRF24L01 wireless module.

Inside the FPGA, [Mark] used a NIOS II soft core processor to orchestrate the complete system and display a nice user interface. He even made another system with an USB host plug to connect MIDI enabled peripherals, allowing him to wirelessly control his creation.

9 thoughts on “Building An Audio Box Out Of Thrown Away Boards

  1. So, where can one find a salvage yard that has electronic items, that also allows browsing? Most of these types of items end up in dumpsters in my area, destined for the land fill, which doesn’t allow browsing due to safety concerns. The salvage yards I have seen mostly contain items that are mostly metal, with little to no electronics….

    1. Good luck finding one. Most yards wont allow people to browse for liability reasons. Another reason is sometimes they have contracts with companies to make sure what they send is scrapped and will not enter the market. Then there is data destruction.

      There is a local scrapyard to me that allows only 3 people to buy from them, one is a friend of mine. When I have nothing to do I go with him sometimes to pick stuff up. It is really amazing what gets scrapped by high tech companies. I got a nice Metcal soldering station, I did have to repair it but that was just a couple caps and transistors.

      1. That has been my experience also. Now that you mention it, the one place I was allowed to browse for about 60 seconds was the collection area at a yearly “bring us your old electronics for recycling” event sponsored by our local electrical co-op. Got a perfectly working Tandy Model 100 for free there….

        Also, love my Metcal so much that I even have a spare backup power supply and wand…

    2. Tough to find – a lot of U.S. states are enacting electronics recycling programs to keep electronics out of the landfills. Recycling electronics is becoming more and more popular due to the precious metals in them.

  2. I have no idea why there are so few comments to this one. Incredible hack! Guy just grabs random dumpstered PCBs, repairs them, then rigs his own backplane and soft-CPU + VGA output bitbanging the output lines just like they used to do on the Atari 2600. Much respect.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.