Fun & Games Music Technology
The Most Beautiful Homemade Device I’ve Ever Seen

I covered British electronics hobbyist Rupert Hirst’s lovely freeform headphone amp back in December, when it was still “just” a skeletonized circuit. Now he’s finished up by casting the meticulously-constructed electronics in clear resin, with equally meticulous care. He built a custom mold from 1.5mm cardstock, carefully sealed the jacks against resin infiltration, and mounted the wire frame inside the mold. After pouring the resin and allowing it to cure, he squared up the block on a belt sander, chamfered the edges with a router, and finally polished everything up with wet/dry sandpaper and Brasso. Rupert’s aesthetic—doing relatively simple things with extraordinary attention to detail—is always inspirational to me.

Crystal cMoy Freeform Headphone Amp

28 thoughts on “The Most Beautiful Homemade Device I’ve Ever Seen

  1. ooooh…Beautiful
    I just wonder (slightly) about heat dissipation and thermal expansion/contraction. I suspect in this circuit it may not be much of an issue at all, but in something more complicated probably could be.

    I might have to try this technique with a thumb drive.

    1. I use a very thin micro-SD to USB adapter. The business end of this adapter is covered with a thin sheet of plastic which breaks after being used for a month or two. Now, when I buy an adapter, I pry the case apart and fill the space behind the thin plastic sheet with epoxy resin, then reassemble it. This makes them last much longer (actually, I haven’t had one break yet).

  2. I’ve seen mechanical samples (electric motors) potted in optically clear epoxy, sliced in half on a bandsaw, the similarly polished to create a cut-away view. As with this project, it turns something mundane into a display worthy object of interest.

  3. When I was a kid (Late 60’s) I found some military surplus avionics that were encased similarly in resin and had a male type plug on one side. I thought they were pretty cool then, this beautiful object reminds me of one of those.

  4. What specific resin did he use to pot this? Excellent clarity and very few bubbles (I think I spotted a few), very good wetting job! Would love to hear his technique for potting!

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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