I'm going to set up a simple, local digital music player out of the internals from an old laptop I have lying around. Yes, I could have ponied up €80-100 for a used Rpi, but I'd rather get some more mileage out of the old hardware, plus I like to tinker.

The player is probably going to run Daphile, and will sit between the USB HDD housing my digital music collection and my stereo amplifier. No streaming required to other rooms or on the go at this time, just a straight, wired connection into the living room speakers.

The idea is to yank the motherboard out of the laptop casing, preserving as many ports as possible, and putting it into a slim customised cabinet instead. It'll probably be fugly in the first version, but like I said — I like to play around with things.

There are two issues though, and I want to solve them in one go if I can. The laptop board only has a ratty 3.5mm audio port — and I'd rather build a DAC into the music player than add two separate new boxes to the stereo setup. So,

  • has anybody tried hardwiring a DAC module directly to a laptop motherboard?
  • if not, does the perversity of the idea somehow tickle your creativity to offer a solution?

I suppose the DAC will also need to draw power from somewhere, so suggestions on that part are also welcome.

What DAC do I plan to use, you ask? At this point I'm undecided. I'm tempted to hack one together myself, but that may introduce too many wild cards into the equation. Alternatively, a simple prefab board with RCA connections. Happy to hear your suggestions on that front, too 🙂

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[–] [S] 1 point 4 months ago (1 child)

Thanks for following up.

Last thing first, I found the sound chip and identified it as a Realtek ALC3236. It's listed on a lot of sales sites that claim to have data sheets. It seems they all link to alldatasheet.com, which only has ALC3246 onward AFAICT. I'll dig on, but at a glance it feels like a dead end.

I don't think I'll have to worry about load on the USB connection; 99% of my music files are still mp3, so it should be nowhere near megabytes/sec? Once I've replaced more of it with lossless audio that may change, but for now I think I'm good.

As for the built-in SATA connections, I think the specs oversold the number a bit. Looking at the mobo I can find only two; one for mounting the system disk, and one for the optical drive. From what I've seen the latter would be noticeably slower than needed for a hard drive. So unless I find a good PCIE to install an NVME disk, I'm probably stuck with USB for now.

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  • [–] 1 point 4 months ago

    I'm not an audiophile, but I have a basic understanding of circuitry. I initially started looking at the PDFs on all datasheet since similar hardware usually has the same features. After frowning at the pinouts and my morning coffee, I realized I didn't really know what I was looking for.

    It turns out that a DAC is an external sound card and both cables are for unbalanced analog.

    That said, you might want to start with a 3.5 mm to RCA adapter, but not because I think it doesn't matter. My reasoning first is that (per link) the purpose of the DAC is to get the audio away from the noise of the PC. My thought is that the component is far enough from the rest of the machine that it might be okay. The second is that you are listening to lossy MP3. Try it, and see if you feel it needs improvement.

    To reduce interfere, try putting adhesive thermal pads over both sides of the board and cover a little larger than the components in that area. Cover the outside of the thermal pads with aluminum foil. Tack a wire from the shielding to a convenient ground, like the housing of a USB out.

    If that doesn't work, then I advise the DAC.

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