Page 1 of 36 1234511 ... LastLast
Results 1 to 10 of 353

Thread: USB Audio DAC mod + LaserBoy Correction Amp

  1. #1
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default USB Audio DAC mod + LaserBoy Correction Amp

    Here are some nice pictures of a hand made LaserBoy Correction Amp and one of those famouse USB sound cards.

    GRIBYX = green, red, intensity, blue, Y, X !

    Cable shield is grounded.

    The twin lead is USB +5VDC and GND (white stripe).

    In order to get the right levels out of this audio DAC, you need to display the provided software effects / mixer application and set it to 6 channels. Then you need to set the level of each channel. This goofy thing has a built in digital gain with automatic digital limiting (YUK! ). It has NO EFFECT if you set the levels to just high enough but not too high!





    See the long, plain black box? That is a DC/DC converter that takes +5VDC and provides +/-9VDC for the op-amps. How cool is that?

    BTW, the printed boards are done and a bunch of parts are on their way! We will have 25 kits available very soon. More after that! Those DC/DC buggers are made when ordered!

    James.
    Last edited by James Lehman; 07-30-2008 at 21:38.

  2. #2
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,091

    Cool

    Excellent! I've got the same sound card sitting on a shelf, just waiting to be modded. Looking forward to being able to run Laserboy on a real DAC. (Also looking forward to trying out Dr. Lava's sound card driver that emulates the Easylase USB DAC. Hoping to be able to play some of Zoof's creations on it!)

    Let me know when the printed balance boards will be available!

    Adam

  3. #3
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Question

    Hey, will Dr. Lava's driver et someone use LDS on a sound card DAC?
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  4. #4
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,091

    Cool

    That's my understanding, Aaron. I'm hoping to be able to use it with Mamba Black myself. (Yeah, I know that Mamba Black has a driver for the QM-2000. I've actually run it that way, but I prefer to run Showtime with the QM-2000...)

    Adam

  5. #5
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Lightbulb

    Quote Originally Posted by buffo View Post
    (Yeah, I know that Mamba Black has a driver for the QM-2000. I've actually run it that way, but I prefer to run Showtime with the QM-2000...)

    Adam
    Amen to that. I'd like to find a "cheap" way to be able to run both, ST and LDS, on separate scanners of course...

  6. #6
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    This amp should work with just about any USB or PCI, Dolby 5.1 or 7.1 surround sound card. I have not tried one yet that didn't work!

    You might have to look a bit farther than the obvious output decoupling caps on some boards.

    In the good old days, I just looked in the Linux kernel to see what DAC chips were supported by Linux drivers and got cards with those chips.

    The card you see on my website is one I got of a shipment of three that cost a total of $21 sent to my door. It's a C-Media 8738 chip.

    Something to note about The LaserBoy Correction Amp: It is an inverter! So if your DAC is NOT an inverter you will end up with an inverted signal! That means that you need to send inverted wave to the DAC so that it can pass it to the LaserBoy amp to be inverted again. Does that make any sense at all? Some audio DACs are inverters, so you send positive (non-inverted) information to the DAC.

    James.

  7. #7
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
    Posts
    2,334

    Default

    Quote Originally Posted by James Lehman View Post
    Something to note about The LaserBoy Correction Amp: It is an inverter! So if your DAC is NOT an inverter you will end up with an inverted signal! That means that you need to send inverted wave to the DAC so that it can pass it to the LaserBoy amp to be inverted again. Does that make any sense at all? Some audio DACs are inverters, so you send positive (non-inverted) information to the DAC.

    James.
    That's OK since both the driver and your wav writer routines have options for inverting the data.

  8. #8
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    Excellent! Pretty soon, everyone will be thinking in waves!

    James.

  9. #9
    Join Date
    Jun 2008
    Location
    Boston, MA
    Posts
    58

    Default

    im back!

    anyways, i have a lot of catching up to do, but i saw this and I am very excited!

    I've been meaning to clean up my external electronics, and a printed board would be quite spiffy. I also told some one I would build them one, but this would be a lot easier!

    Cool James! Will you be selling the kits with parts and the printed board? Any ideas at what the cost is going to be?

    Barold

  10. #10
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    DrLava and I put it together. He's got the boards and I just ordered a bunch of parts. We don't have printed instructions yet, but you already know everything you need to know!

    James.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •