DIY boxes

I’d like to make something along the lines of this interesting box:

I have previously made passive boxes meaning they are not powered but using circuits like Mutable’s Ears I’ve amplified the contact mics. I have experience at building circuits from kits but I’m just not sure where to start with something like this.

Does anyone have any circuit designs with guide notes for building an acoustic box of a similar type? I want to use springs, strings, motors, solenoids, contacts etc to create a range of different noises - rhythmic and otherwise.

Interested in more knowledgeable or experienced experimenters opinions on where to get started. I’m particularly at a loss regarding wiring and power.

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I can really recommend a copy of Nicolas Collins’ Handmade Electronic Music, which touches on similar topics, and elements of this level of simplicity.

What seems to be going on in that box, visually, is:

  • there’s a contact mic going into some kind of contact mic amp. This is powered from the 9V supply.
  • there’s some acoustic sound-making things - strings, springs - and a motor fed from the supply, possibly with a pot in the way to alter its speed.
  • there’s a simple amp of some kind and a speaker.

so really, most of it is your standard passive box, with one/two extra components. If you’re looking for a headphone amp circuit, the CMoy circuit is simple and works really well. To amplify a contact mic from a unipolar power supply like a battery, the Alex Rice circuit is good.

I appreciate that’s not a ton of detail, but the Collins book starts from the point of view of ‘a contact mic’ and goes from there, focusing on battery circuits; it’s a lovely thing to have anyway. And then, at the other end, you’re making something out of building blocks: a couple of distinct units (mic amp, speaker/phones amp, connections, perhaps a motor circuit), which you can build up in turn.

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Have you had a look at the Koma Field Kit? (The first one, not the FX.) That could fill in a lot regarding power and signal amplification, leaving the sensor part up to you.

Yes I was one of the original backers of the Field Kit. To some extent I’m expanding on what I have there and adding in some extra elements. The other aspect to my interest is expanding my skills and knowledge.

Thanks for mentioning Nicolas Collins. I’d forgotten that I had a pdf of his Hacking Manual - an early version of the book you referenced. I’ve now located it so I’ll give that a good look over. It’s the obvious jumping off point … thanks again. I’ll look out for the updated version.