DIY USB Stereo Headphone Amplifier

The biggest and best audiophile projects are usually huge tube amps, monstrous speaker cab builds, or something else equally impressive. It doesn’t always have to be that way, though, as [lowderd] demonstrates with a tiny DIY USB DAC build that turns a USB port into a headphone output.

In the Bad Old Days™ putting a DAC on a USB bus would require some rather fancy hardware and a good amount of skill. These days, you can just buy a single chip USB stereo DAC that still has very good specs. [lowderd] used the TI PCM2707 USB DAC, a chip that identifies as a USB Audio Class 1.0 device, so no drivers are needed for it to work in either Windows or OS X.

The circuit fits on a tiny PCB with a USB port on one side, a headphone jack on the other, and the chip and all related components in between. There are some pins on the chip that allow for volume, play/pause. and skip, but these pins were left unconnected for sake of simplicity.

The board was fabbed up at OSH Park, and the second revision of the case laser cut out of bamboo and acrylic by Ponoko. It’s a great looking little box, and something that fits right inside [lowderd]’s headphone case.

26 thoughts on “DIY USB Stereo Headphone Amplifier

    1. There are many writers that contribute to hackaday, but 95% of complaints about spelling and grammar seem to revolve around one writer “Brian Benchoff”. Personally I don’t really care if the writer can spell or if he graduated the 3rd grade, but when I click on comments I want to hear about what people think about the project, not how awful Brian is. Complain to the hackaday editor, create a greasemonkey script that blocks his posts, cut off his head IDK. If you post something in the comments make sure it’s about the project. Example that’s a nice circuit board the soldering work is amazing, but what’s with the wooden box, wood is an insulator.

      1. HaD need a mod system. It needs an “English Major” mod. People who love nitpicking on that stuff could set a preferenced to show posts that are moded “English Major” while others could hide them. This would be best if it were a seprate rating and filter system from any good/bad troll/insightful sort of stuff.

  1. While its nice to have a dedicated output, there have been “USB Soundcards” for quite a while. Some even offer S/PDIF outputs, in electrical and optical format.
    I used one of these with a Raspberry Pi when they were first released, in an attempt to get 5.1 channel sound into a [non HDMI compatible] amp. unfortunately, there was always a delay – so sound never synced with the video out. The amount of delay varied depending on the format of the video, so I never overcame that point.

    Maybe newer sound cards & development boards are better.

    1. Some video playing software has an option to delay sound in milliseconds, including negatively (ie in advance). I’d be surprised if the Pi couldn’t, but it’ll presumably be in some nebulous txt file somewhere. With it’s own standard and format. Like everything on Linux.

  2. Cool but I feel stereo is getting outdated.

    Maybe it’s just me as I’ve been using 5.1 surround headphones for 2 years now. Digital via HDMI to SPDIF via adapter to analogue via amp that came with headset. They also have 5 drivers in each cup. Valued at $140 USD.

      1. As long as we have 2 ears that we can deliver sound directly to, there is no need for more than 2 channels. I am absolutely unimpressed with 5ch headphones compared to this, with simple stereo ones:
        The trouble is, we still don’t have a good way to deliver that sound without headphones, that is where x.1 comes in. But realistically speaking, I have yet to hear a multi channel system where I could not find “artifacts”, be it in cinema or someones home. It does not sound natural.

  3. “In the Bad Old Days™ putting a DAC on a USB bus ”

    Huh? The “bad old days” were when Gravis Ultrasound was your only choice for quality sound on your computer. Probably one of the very first USB devices I ever bought was a 5.1 DAC adapter. It worked like a champ then, and it still works like a champ today. When were these “bad old days” of USB audio? I must have missed them.

  4. What I could really do with, is an amp between my phone and wired headphones, to make music louder. The phone just puts out a pathetic amount. Could also do with some sort of preamp software for Android, that works in realtime, for all the MP3s that are too low-level. I’ve got an MP3 gain-adjuster on the PC, but it works in batch mode, it’s a PITA having to do it that way.

    I did try some new audio players on the phone apart fromthe existing Android one. But I use Bluetooth headphones currently, and the play / pause button on them didn’t control the new audio player, it just kept summoning up the Android system one, while I’m using Winamp or whatever.

    Is there a good guide for sorting Android’s shit out, for people who already know a lot about computers? There’s a million “how to switch your phone on” for simpletons. But then I guess they’re easier to write.

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