BabyPlate...
From the original Analog Industries archive. Some links and images from that era no longer resolve.
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:
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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.
29 comments
nicely done! sounds interesting and useful. this one turned out well!
I've been wanting to do something like this for a while, nice job. Is it hard to find the driver normally, do I need to go find one of those paper amps? I just assumed it was something you could pick up anywhere.
bb
You can always use one of those window speakers; (like so: https://www.amazon.com/dp/B0042L29KW/ref=as_li_ss_til?tag=analogindustr-20&camp=0&creative=0&linkCode=as4&creativeASIN=B0042L29KW&adid=0NTAPQ9H92XFQVRQ2G79&; ) that's actually a much better solution than what I did, and I'll probably swap the Paper Jamz transducer out for that, or something similar. You can also take the cone out of a speaker, and connect the transducer itself to the plate via several different means that are described in various places around the intertubes.
-CR
I've been wanting to build a plate verb for ages, but just never got around to doing it. No I have to, or risk looking like I'm lazy. This also reminds me that I need to finish my tiny reverb tank made out of a broken water heater tank project. Keep the fun going. This series is really inspiring me.
-William
I'm with boobs.
interesting. a couple comments:
-shouldnt you hang it horizontally instead of vertically like it is now? as it sits, all the weight it on the top springs, not divided evenly amongst the 4 springs. i think this would yield "better sound"
-whats the thickness of the metal plate?
-anything else that could be used in place of the pickups? im thinking rat shack piezo transducers.
-to make this stereo, you could duplicate the whole thing and make 2 of them, or could you just put two pickups on it in different places on the plate?
awesome! i'm curious how the old EMT plate units worked in terms of their plate suspension. having never seen one up close and personal i mean...anyway i like its quality - not a spring, definitely, but not quite a full plate sound either, although given the fact i've only heard emulations of plates in most cases, i'm certainly no expert.
anyway - win, indeed.
@soundsubs: I initially tried it horizontally; the difference in sound between the two configs is undetectable, to me at least. The plate itself isn't heavy enough to counteract the top springs' tension in any meaningful way. The difference between the top ones' stretch and the bottom ones is about 1/16th an inch.
As I said in the OP, the steel is 26-gauge, which is .0179 inches, or about 1/64th inch. Pretty thin, in other words. 26-gauge cold-rolled steel is what is used in most plates; there are a couple that use stainless, but the EMTs, the gold standard for real plates, use 26-gauge cold rolled. I would get better propagation at this size with thinner steel, but the obverse is that thinner steel won't have any structural integrity to speak of. Ergo, this is about as small as a meaningful plate reverb can be.
Regarding the piezos, that is exactly my intention. I have better quality ones than the shitty Radio Shack ones, but they have the same net effect. We'll see how it works. I plan to try mono-in, mono-out at first, and I may make a second one and double them up if I get more inspired.
-CR
If you'd finished it a wee bit earlier you could have put it on the Mars rover, then you wouldn't have to worry about orientation hardly at all. Latency might be an issue though.
To my super special reverb nerd ears, it has the immediate diffusion of a plate, but with the "ringiness" of a spring reverb. The ringing is associated with a lower number of resonances, or more space between resonances. Kinda like turning the Size control on Eos way down.
Slightly less geeky description: It sounds like the plate version of the short spring reverbs that would have been built into synths, like the ARP 2600. Very unique and cool.
I moved into a new place six weeks ago, and I realized there is this void next to my studio (roof slope) that would be absolutely perfect for a plate. Don't have the skills/tools to do such a thing. Well done, sir.
This is perfectly timed to compete with DSP Doctor's introduction of the Pluto Plate.
There is a slight financial differential, though.
http://bit.ly/PEaGvJ
- c
does it matter where the pickups are in regards to the transducers? ie, does farther = better?
how about shape? are there resonances of a rectangular piece of metal that could be tuned either by cutting or by damping?
-metaphysician-
A real EMT is just freakin fantastic. That and one of those AKG springs is some kind of reverb heaven. You need a room to keep one in though, they are big and impressive.
bb
Also, if you listen on monitors, they can't really be in the same room as you due to feedback. As I do 99% of my work on 'phones, only switching to monitors for the final mixdown, I can print the electromechanical shit, and not worry about it.
Most of an EMT plate's mass is in the supporting framework (which is extensive) and the wooden box that surrounds it. The actual plate itself only weighs in at about 20 - 30 lbs. But the whole unit is... gigantic would be the first word that comes to mind. And extremely heavy.
Regarding stretta's comment, I've actually had the exact same thought. I was pondering making a gigantic spring reverb in the ceiling. But seriously, if you have an empty space like that, and your shit isn't too loud, you can just hang a piece of sheet steel (thinnest gauge you can find, usually 26), put a thumper in the middle, and a pair of transducers (active acoustic guitar pickups will work splendidly). There's really not very much to it. If you want to use a damper, you can just tape a sponge or some shit to a broom handle, and lean it against the plate in a good spot.
Matt, I have to come to Cambridge next month for a meeting; I'll be happy to help you make one. It's a pretty simple process.
-CR
I just had a rather large piece of 24 AWG stainless custom cut for the front of the kitchen island I'm building. The metal place insisted on me buying the entire 4x8 sheet, so now I have two pieces on my porch, one of which is roughly 2x5. And now I know what I'm gonna do with that sucker. As an aside, it was impossible not to notice the awesome array of noises the big piece for my island made while shuffling it around.
There are a few how-to guides on building your own spring reverb. It seemed like more work than I wanted to do. I do have the metal back of our old dryer that I've used in experiments with a Creme Demented bottlecap contact mic; it's fun to hang in front of a guitar amp and record it's vibrations....
Amazing recreation of the first 20 seconds of every Cabaret Voltaire track!
So could you have multiple transducers and create a 'multi-tap reverb' so to speak?
Sonically a bit of a mess probably but, y'know, nothing ventured...
You can do whatever you want. Generally, with one this small there's not much separation, but the way it propagates, I think if one put one pickup at the top and another at the bottom, with the transducer in the center, one could get a stereo-ish signal. I'll try a number of configurations, see what gives the best result.
But the way these work, you're not going to pick up different _times_, per se. More like different phases. Think of it this way: on a guitar, the neck pickup and the bridge pickup don't pick up different pitches, right? They pick up different timbres due to the way the string is constrained at the bridge, but they're the same fundamental.
-CR
i'm with sean.
@bongo - i'm old enough to have been excited to get a spring reverb in the mid 80's - A Tapco 5 spring mono job - before they became retro cool and expensive. upgraded to cheap digital reverb a few years after that and didn't look back. only ever heard plates on old Vangelis or Klaus Schulze recordings.
Oh, you've heard plates. They're used every day and on many, many recordings.
I have several springs, but not a big AKG. Those are totally different. A digital emulation of a spring is pretty hard to do, it appears.
bb
Yeah. EMT plates (and the couple other companies that make them) are found in pretty much any real commercial studio, and are the go-to vocal reverb. You've _definitely_ heard them. A lot.
-CR
So you're saying the bigger, the better? (the other piece of scrap I have is real damn big)
bigger is generally better up to a point. the EMT plates are something like 4 x 8 feet, don't remember exactly but something on that scale. the adjustable damper is basically an acoustic absorber panel that you can move closer or farther away from the plate surface -- the effect is there even if it isn't touching the plate.
never bought from this site before, but he has some of the nicer PVDF piezo contact mics (more neutral response than the typical gold disc):
http://contactmicrophones.com/
nice project chris; actually doing the things that others only think about doing.
ed
If memory serves me correctly (it is too early to ask the Googles; we have a hard 9AM rule in this household) the EMT 140 is 1 x 3 meters. This is the de-facto standard size for normal plates, best I know. I'm willing to be wrong on that, because I'm dragging the info out of my demonstrably faulty brain.
-CR
the size was just a guess, probably distorted in my memory by the larger size of the frame and cabinet. or maybe by the hours it took me to clean one that had started to corrode a little. 1 x 3 meters sounds reasonable. not sure if the ratio has any particular significance, but could be a reference point for anyone attempting to make their own.
interesting to hear about the 9AM rule; may have to try that (or a version thereof) in our household as well.
ed
Hey guys,
I just wanted to pop in, and post a link to the "Pluto Plate" that beauty pill mentioned above
check it out;
www.plutoplate.com
peace
A/B
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