I’ve been wanting to make my own stomp-box for literally years. If you need a quick intro, a stomp-box is just something you can rhythmically hit with your foot while playing. Essentially you become your own percussionist. It can add a lot to a solo performance, especially a harmonica one, as you can’t back yourself while singing like you can on guitar, for example. You can buy commercial stomp-boxes, of course, but it’s far cooler to make your own.
Most stomp-boxes use a kind of pickup called piezo (pee-Yay-zoh). These are small contacts containing a kind of compressed crystal. The crystals turn vibration from a moving surface (e.g. the body of an acoustic guitar, or the lid of your stomp-box) into an electric charge, which can then be amplified. Thus, stomp on the box to wobble the surface and you get a thuddy, percussive sound out of your speaker.
I’ve used a different technique I first read about here. This method uses a magnetic pickup from a bass guitar instead of a piezo. Magnetic pickups use coils and magnets to create a magnetic field that is disrupted when you wiggle some metal close to it (e.g. a guitar string, or for our purposes, the lid of a tin box). That gets converted into an electrical signal which can then be amplified.
I like the magnetic pickup idea more as I’m not a fan of piezo pickups in general and I’ve read about them sounding pretty weak for stomp-boxes. Just seems like a neat, solid, solution, and I was hoping to get some interesting sounds out of it.
To that end, I ordered the cheapest P-bass pickup I could find on eBay (I forget exactly how much I spent but it was way under a tenner). Then, I ordered a good quality Switchcraft input jack (a couple of quid) and found myself a suitable tin. This tin used to contain chocolate, I bought it from an airport gift shop.
Putting the project together is really straightforward. Just solder the pickup to the output jack and mount both in the tin. That’s it!
Straightforward it is, but I own neither a drill to make a hole for the output jack, nor a soldering iron to connect the parts, so I enlisted the help of my friend John from acoustic duo Robber John. He has the tools and knows how to use them.
John put the thing together for me on a sunny spring morning in Slaithwaite. The only additional item needed was a block of wood John cut to mount the pickup on. It needs to be very close to the lid to work properly. The wooden block takes care of that.
John glued the wood to the tin, the pickup to the wood, then soldered the pickup wires onto the jack socket, stuck that in the hole he drilled and…… done. Worked the first time too.
As for the sound. It’s pretty good! The first thing we noticed on plugging it in was how accurately the pickup converted the sound. It really does sound like someone tapping a tin box with their foot.
We talked about adding volume and tone controls to the box, but I decided to keep it simple for now and use it for a while. If I feel extra control is needed I can add them down the line. I can EQ bass and treble to taste on the active PA speaker I use anyway.
Once home with my new toy, I needed to find a way of stopping the box from sliding around too much during use. I added some furniture anti-skid pads (mounted to a bit of thick cardboard so the height exceeds the lower rim of the tin). Seems to do the job okay for now, but I might need something a bit more robust for frequent live use.
I think I also need to put something else in the box to weigh it down a bit. Nothing seems obvious right away so I’ll just keep that in the back of my mind and I’m sure something will turn up eventually. Also, the lid may need reinforcing a little as it’s possible to stomp too hard and cause it to contact the pickup. This makes an unwanted clicking sound.
Overall though, it’s a super simple project I should have sorted out years ago. All I need to do now is put the practice hours in so I can actually play the thing properly. Meanwhile, here’s a quick demo.
UPDATE April 23rd 2022. I just had a brainwave and stuffed all the empty space inside the tin with a jiffy bag and some bubble wrap. This removed a lot of the tinny noise and made it sound more bassy and thuddy. I liked the way it sounded before but it’s much better now. I needed to wrap a bit of tape around the box to keep the lid on though. An unforeseen side effect is that the tendency for the lid to get too near the pickup and create unwanted sound is significantly reduced. Win.
I’ve also had a change of heart about the weight. I always travel as light as possible because I’m extraordinarily lazy. Better I think to upgrade the non-slippiness of it. I’ll have a think on that.
UPDATE UPDATE, Same date: Just thought, while I’m sorting out the non-slippiness I wonder if angling one side a bit higher (like the pic of the wooden commercial box above) might be beneficial for both comfort and sound. I’ll bear it in mind.