A noise box is a great introduction to building simple instruments.
You require a limited number of parts, many of which you can salvage from old or defunct equipment. In it’s very simplist form all you need is an old tin, a piezo pickup, socket and spare hardware such as springs, nuts and bolts.
You also need a limited number of tools – pliers are helpful and you’ll need to solder a couple of wires and be able to drill holes in the box or tin that you use. Small clamps can also be useful.
I had an old tin that used to contain plasters and a range of nuts, bolts and a couple of springs I salvaged from old electronic equipment. I already have sockets and piezo pickups in readiness for such a project.
The first thing to decide is what you want to include on your noise box. Springs are a very popular choice because they tend to resonate quite well. The great thing with making a noise box is that there are no rules. You’re only limited by the available size of the tin and your imagination.
This tin is quite small, ideal for a first project. The main size constraint is that standard guitar jacks require a 9 – 10mm hole so your tin needs to be deep enough for the jack to fit without the connections touching the top or bottom. On one side I’ll have a spring, on the other I’ll add a couple of bolts with grommets and maybe put an elastic band on.
The first task is drill the holes. Being a tin and fairly thin metal this is fairly straightforward. One at the bottom for the socket and four for the bolt holes.
These are very useful – stepped drill bits. It means you can drill a small pilot hole, say 2 – 3 mm and use this to get the correct size, I find it easier than drilling a bigger hole to start with.
One issue with a tin like this is you don’t have much room to work, it would be much easier with a removable rather than hinged lid. I would normally fit the socket then solder the wires but in this instance I solder the piezo wires to the socket before installation. It makes it easier using pre-soldered piezos. They usually have a red wire for the output and black for ground. The socket has two connections, tip and ground so I need to make sure the red wire is connected to the tip connector on the socket.
Two bolts go in fairly easily, I hold them in place with pliers whilst attaching the nuts to fix them in place. The other two bolts are too long to fit, even after cutting down. I have a couple of spares that I use instead.
The socket is a bit fiddly to get in the hole, more than expected. This because there is a burr on the inside of the tin. Difficult to file, I use a small file from the outside which gets the worst off and allows the socket to fit in place. You may find this is more likely to be an issue drilling holes in thin metal tins like this.
With the socket and bolts in place, I can attach the piezo. It’s a case of gluing it to the tin and I have a small clamp that will hold it in place.
With the piezo glued in place, I attach the spring. It is fairly tight, maybe should’ve paid a bit more attention to the stretch before drilling the holes for the bolts but it does work ok. I also glue a push button switch – it’s not connected as such, more for the click noise. I put grommets on both bolts initially but replace one with a picture hook and small hooks to provide rattle sounds.
The assembly process takes me less than an hour although I leave it a few hours for the glue to fully dry.
Now the big test – does it work?
It does, and really well. I test it with a multi-fx unit and it sounds good with fuzz, delays and reverbs. In fact the piezo is so sensitive it even picks up the sound of me pressing buttons on the effects unit. Using a standard guitar jack allows you to easily connect the noise box to guitar pedals / effects units and then connect to a guitar amp or an interface to record the sounds on a computer.
Using bolts allows you to easily change the hardware at a later stage if desired. You can fine tune the size of spring for example or easily add other noise creating options. Anything that rattles, vibrates or scrapes is fair game!