August 5, 2012
by Chris Randall
I was at Target a couple weeks ago, and (as I occasionally do) I took a quick browse through the toy section to see if there was anything that could be construed as "cool," and furthermore "neat," and could be co-opted in to being used as a musical instrument. As luck would have it, they happened to be blowing out these for $2.50. It is essentially a cardboard box with a little battery-powered amp inside and a 3.5mm jack input. I thought it would have a little speaker, but when I opened it up, it turned out to be a transducer attached to the cardboard of the face with double-stick tape.We'll leave aside the tedious discussion about the fact that speakers and mics are essentially the same animal, and that all mics are transducers, as are all speakers, and just hope that the members of the Pedantic Posse can be happy with that. Hope in one hand, of course. But, given the context, I'll just assume that you know what I mean and move along.
So, looking at this contraption, my first thought was "PLATE REVERB!" I didn't know if such a tiny transducer could move a plate of any size, but as it turns out, it most certainly can. I drove over to the Industrial Metal Supply shop, where they have an excellent department of leftover pieces of cold-rolled steel for $0.69/lb. I bought two 1" square tubes that were 4' long for the uprights, and a piece of 1' x 3.5' 26-gauge steel sheet for the plate itself. Total $10.90. I then bopped over to Ace Hardware and grabbed four little springs to hold the plate, which ran me $7.25. Total spent: $20.65. I had some scrap lying around for the cross-pieces and the feet, but if I had to buy that metal as well, it would have been another $2 or so.
Anyhow, took me about an hour to build the thing. I didn't get fancy and dress the welds or sand the whole unit or anything, as I didn't know if it would work or not. It stands about 3 3/4' (just over a meter) tall, and as I pulled the amplifier entire out of the Paperjamz thing, it runs on 4xAAA batteries, of all things. As to how it sounds, here's my first test:
BabyPlate by Chris Randall
That's with the Barcus Berry piano transducer I've been using. I also have some piezos for it, which I will install in the fullness of time, as well as coming up with a more permanent mounting solution for the transducer. The drums are from Tattoo, and I gradually roll the send knob up from 0% to 100%. The only "production" I did was to roll off the low end on the reverb return, as that Barcus Berry pickup has too much bottom for this usage. When I install piezos, I expect that problem to go away, as they don't normally have the big lows that this pickup produces. But long story short, I got a portable battery-powered plate reverb that doesn't sound half awful for $20. I'm gonna go ahead and put that in the Win column for the day.