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Homemade E-bow.


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This page is in Dutch, but the schematics are there - a Google translation should get you close enough to start experimenting.

Dutch Ebow page

Well I'll be... :D That's actually part of an instrument building course...and the school where it's teached is like...20 km from here. Small world isn't it?

If anybody wants a translation, lemme know


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I know how they work but what is their usable purpose for most people? I hope he has tried one and knows what they can and cannot do.

i kind of have the idea, but my main purpose for buying/building one is so that I can play Opeth songs and various songs with strings or wind instruments in them..... like that flute melody in the Mamma & the papas' "California Dreamin'"

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Yeah, that can't be an EBow, can it? There's no output on an Ebow in the traditional sense of an audio signal. Besides that, to make an Ebow you would HAVE to know how it's constructed, too, no? Can't just hook up the internal components in any old fashion.


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Look a little closer - the output is a cannibalized transformer that's been reconfigured as a magnetic transducer to drive the string. That's probably as close as any of us is going to get to the schematic unless somebody is willing to destroy their Ebow in order to re-engineer it (or maybe bribe somebody at Heet to get us the original schematic :D ). Since psw's been messing with this basic idea for quite a while now, he's much better qualified to speak to the requirements for an efficient driver, but the circuit itself is very much workable.

Tim, it looks like we probably do need that translation, if it's not a lot of trouble. :D

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Here you go :D

It is commonly known that an electric guitar can produce sustained sounds as long as we are positioned close enough to the speakers at a high enough volume.

Even without this somewhat brutal technique it's possible to play sustained notes on stringed instruments with magnetic strings. For that, since many years there's a tool on the market called the e-bow.

we hereby give you the full text and drawings of the original patent.




*picture of e-bow*

Building this device yourself is quite easy for any good handyman.

To start out the ones who like to experiment (see chapter two of this course for a deeper understanding of the project),here are some practical pointers and schematics.

In the schematic below we used an LM386 ic. For some more power you can also use an LM386-4, but that one has to be fed by a 15 to 16v DC source, instead of the 9v battery

*picture of schematic*

the amplification of this design is about x200, or 46 dB. For optimal performance, the electro-magnet of the driver (the output end) needs to have a low resistance (about 8 Ohms).

You can use an output transformer of an old transistor-radio, where you remove the iron core and replace it by a permanent magnet. The pickup-coil can be of high resistance. For use as an ebow, the driver and pickup coils need to be mounted close to eachother, but so that they barely keep from oscillating when idle. You can verify this by means of an oscilloscope (easiest), but also with a current meter in series with a battery. When the current is large (over 10 mA), and there is no metal object resonating, you can be sure the device is oscillating on it's own. In that case, the distance between the two colis needs to be larger.

If you can't get it to work woth lower frequencies, it might be necessary to place an RC-network in parallel over the input.

Evidently, you can also test the principle by using an ordinary audio amp,where you connect the pickup coil (which can also be the pickup of an electric guitar) to the input and the speaker out to the driver coil.

dr.Godfried-Willem RAES, course on experimental music


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Just buy one! You will spend a lot of time screwing around with it trying to get it work, and there is the problem of housing it in something that is practical and usable. Even I, Mr. D.I.Y., wouldn't bother with it. Your time is also worth something isn't? (Unless you want to do it just for fun, then go for it)

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Here I am...Mr Sustainer Expert :D

That circuit is plenty good enough, and pretty much what's in an Ebow so if you wan't to make one...there it is.

I actually was going to make it as the circuit is pretty much identical to the power amp section of what I'm using in my sustainer devices...so all I needed was the pickup and driver.

I found a transformer (very small) in an electronics shop but...those buggers are just about impossible to crack open to remove the core as I think they were suggesting, plus, they claimed the primary was 8 ohm but I only measured it as 1! (there's tolerances for you)

My intention was to use a reed relay (1K ohms) as the pickup with a magnet inserted where the reed goes. I destroyed that in trying to remove the end to get the reed out...it seemed to have been wound with the reed in! I'm not sure what they mean by telephone pickup in the schematic.

Anyway...after these experiences, you're probably better off winding the driver coil yourself...but then if your going to do that...you might want to consider a full blown sustainer.

Basically, where the sustainer thread has got to now is... a giant ebow. It uses the bridge pickup as the source and you need a preamp to feed this LM386 poweramp schematic (because it will load down the guitar's signal and provide better input impedance matching) and a driver you can easily wind yourself.

There are quite a few who ask me about the actual circuit details from some of my experiments...but really they are quite simple. Any amplifier would do, the LM386 is the obvious choice because it's small, powerfull and will run happily on 9 volts so it's ideal.

The beauty of the ebow is in the execution of the design. The matching of a pickup and driver coil on the verge of oscillation in such a compact device is pretty good. Could you make your own that's as compact? I have no doubt but it will probably cost you in attempts as much as simply buying the device.

The sustainer though, I think is a different story. I think that a lot can be done DIY with this with remarkable results. The one I've got running at the moment is really good. Clean, powerfull, endless sustain...plus all those ebow tricks like note swells, etc...and you don't have to ditch the pick or your technique to use the device!

Not that I'm biased...I really have nothing but admiration for the ebow...it's really a beautiful thing...but these things are not effects boxs (i.e. signal processors), they become a part of the instrument as soon as they hit those strings.

So, it's not as simple as simply being able to correctly follow a schematic. You only have to check around to see all the questions like this that have gone unfulfilled. I'm sure people have successfully made ebows...(effectively, I've made quite a few B))...but it's not as easy as it would at first appear.

Anyway, I'll leave you to ponder these thoughts...with a plug for the sustainer thread. I have made a driver that works pretty damn well (a few of them recently, so it's no fluke!), but the next one will actually be a part of the neck pickup. I've found a single coil pickup that can be fitted with a blade (an unusual bobbin design as it originally had poles!) and I'll be mounting the driver on top of this.

Hopefully what will be achieved is a normally functioning passive neck pickup (for use without the sustainer) and the sustainer all in one package. The thing will look identical (except for the blade) to a normal single coil. I may even set the thing in black epoxy for an EMG kind of look.

So...I hope that helps a little...if you want to know more about the current DIY sustainers...ignore the early part of the thread and skip to the last few pages for details of the kinds of thing I'm taking about.

good luck :D


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As for the usage, Robert Randolph is using one on the pedal steel. It's really cool with the slide. After 20+ years of playing, thinking I had no use for one, I finally kind of want one. Making one would be cool because I could tailor it to my hand, and whatever way I felt like holding it. I play slide on my lap, as well as lap steel, and it might be cool to make one with a perpendicular handle, so you could hold it like you're holding your slide, instead of having to hold it in the direction of the strings. Ooh how about one with a rotating handle?! Ooh how about I just shut up and go buy one?...It'll probably take me another 23 years to decide.

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Now slide.....

I made a powered slide. Basically you cut the cone off a little speaker (and the rim around it) and what you have is a smooth magnet. If you power it up with something like the circuit above the "slide" vibrates and creates an ultra-cool powered slide! As long as it's far enough from the pickups it wont squeel but anywhere over the fretboard is fine. The whole thing could be mounted in a box with a lead running up to the "slide"...neato party trick!

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