More car audio input hacking

[Dave] pulled the head unit out of his dashboard to add an iPod input. He took a much more invasive route than the other hack we saw a few days ago. He actually patched into the audio lines going from the Dolby reader head chip to the amplifier.

The first step was to trick the deck into thinking it had a cassette inserted. He scoped an enable pin on one of the chips to discover the timing and emulated that signal using a PIC microprocessor. From there he popped off the chip that reads the tape data, patching directly into the audio out traces. This presented some noise issues when charging the iPod but [Dave] fixed that with some decoupling capacitors.


  1. Brennan says:

    That is just TOO COOL. Great job man!!! Truly the definition of a hack!

  2. andrew says:

    This is so awesome, all these aux input hacks are inspiring me to finally do something about the failing CD player in my Mazda Protege.

  3. Jack says:

    Lindstrom wire cutters are the best!!

    Oh and good job by the way :) it’s always nice to see a simple but effective hack.

  4. vonskippy says:

    Very sad that his work bench got destroyed by a hurricane.

    Is there a “save the workbench” foundation set up to take donations?

  5. hawkeye18 says:

    Wow, he didn’t hack that head unit – he made it his bitch. Very nice!

  6. Eric says:

    where were thess input hacks 5 years ago when i needed them?

  7. Ryan says:

    Wow, looks just like my work bench.

  8. George Johnson says:

    Yeah, I was going to ask if that was indeed a pair of Linstrom cutters down there in the lower right hand corner. Fantastic cutters! Will last a ligt time unless you seriously abuse them.

  9. Hitek146 says:

    Holy shit, I can’t believe how much those Lindstrom cutters cost! When I was with TI, they supplied me with an awesome set of cutters similar to this, but with a black tapered steel flush-cut head, hard green squarish(in cross-section) handles and a golden(if I recall correctly) silk screened logo, of which manufacturer I don’t remember, but wish I did!

  10. Hitek146 says:

    Hmm… Searching a little, the molded grips looked similar to the Velleman VT100 cutters(but with a flat, not glossy, finish). Unlike the Velleman cutters, though, the ones I had were not the stamped-steel type, but the milled-steel type, with a head similar to the head on the Lindstrom. I can’t believe that Google is failing me here… :)

  11. Steve says:

    My work bench looks WAY worse then that! Cut him a break.

  12. cde says:

    If you could find the datasheet for the tape deck control IC, it would be simple to take over the builtin controls without modifying the front buttons without the hacking he had to do.

    As for using a pic, if it’s just a delayed enable, wouldn’t using a large enough capacitor work as well?

  13. Marto says:

    mmm… Lucas aids. The drink of gods

  14. strider_mt2k says:

    A messy workbench is a loved workbench.
    -and this one isn’t even that messy. ;)
    (not to imply that it isn’t loved)

    I’m a Snap-On man personally, but any fine quality tool is worth having when you work with them and take your work seriously, especially if you spent any time at all getting along with um, shall we say…LESS than fine quality tools.

    The hack? It’s awesome.
    I’d do the same thing if I still had a cassette player.

  15. fartface says:

    Old hack. Guys have been doing this to stock and other stereos for a decade now.

    Most everyone in car audio circles knows about this.

  16. Alex says:

    errr…. wouldn´t it be simpler and easier just to make a cable and connect to the AUX port behind the stereo?? Than having all this trouble for doing something with exactly the same result??

  17. Farris says:

    Alex, not all stereos have AUX inputs on the back.

  18. Alex says:

    good point, sorry didn´t think of that…… noob comment of mine.

  19. Jordan says:

    Hey, I just remembered seeing this and feeling left out. I know this is old to be posting on, but maybe this will help someone else out :). I have a 2004 Subaru, and as some of you may know Subaru wasn’t too keen on the idea of AUX jacks until around 2007. I found a way to cut into the FM traces and have a fully functioning head unit with an AUX jack and no stupid “noiseless Blank cd” playing.
    Heres a link

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