I was at the DIY swap meet last weekend where I was shown a DIY “e-bow”. It consisted of an electric motor, 9V battery and switch. The shaft of the motor had what looked like a propeller made of electrical tape. The idea was to turn the motor on and hold the device so the spinning “propeller” of tape brushes the strings of your instrument thus creating a sustained sound. (If you left this at my table at the swap let me know and I’ll try and get it back to you)
Sounds pretty kooky at first, but this is not the first device to use this idea. But, before we go any further an explanation of sustainer and e-boy are in order.
The name sustainer, I’ll guess, comes from the sustain pedal on an organ or piano. The idea is to add sustain to the instrument. With stringed instruments you need something to drive the strings. Violins, violas etc, use a bow. I seem to recall reading about some type of hurdy gurdy that rested a spinning wheel on a string to act as a infinite bow. (Feel free to chime in with some details if you like.) When it comes to guitars, electric guitars that is, the classic sustainer is amplifier feedback. The sound coming out of the speakers begins to drive the strings, which in turn creates more output from the pickups. I have often seen guitar players control feed back in various ways, one method is by pressing the headstock against the amplifier cabinet, which is a good way transfer the sound vibrations directly from the amp to the guitar.
Beyond feedback people have come up with very clever methods sustain. These fall into two methods: Physically vibrate the string or magnetically vibrate the strings. (Note that there have been several stompboxes called “sustainers”, but these are really more in the compressor limiter category).
Magnetic sustainers work on the concept of using an electro magnet to drive the strings. Really this is almost the same as driving a speaker cone. A signal from your amplifier is used to create a fluctuating magnetic field. This field pulls or pushes the speaker cone towards or away from a magnet in the speaker. The field itself mirrors the audio.
Magnetic sustainers use the same concept as a speaker. The difference that magnetic field is pulling at the strings on your guitar. Magnetic sustainers can be either hand held, like the E-Bow, or mounted in the Instrument like the Sustainiac.
The E-Bow is a small hand held device that contains small pick up similar to a guitar pickup and magnetic driver. The signal from the pickup drives the driver which makes the string vibrate. The more string vibrates the more signal is generated at the pick up which in turn creates a stronger signal at the driver. Sounds a lot like amplifier feed back in some ways.
The Sustainiac is system that replaces the neck pick up on an electric guitar. It works with the bridge pickup, amplifying the signal and powering the driver in the neck pickup. Sounds a lot like the E-Bow, except the Sustainiac mounts in the guitar. Moog music makes a guitar that has six magnetic sustainers, one to drive each string.
The next category of sustainers are mechanical sustainers. These would work by physically vibrating the strings. There was a device called the Gizomtron (love the name) that mounted on your guitar and used small wheels to drive the strings. Sustainaic also makes a sustainer, called the Model C, which attaches to the head stock and provides mechanical sustain by vibrating the headstock. Which brings us back to the motor and the 9V battery. Can you make a sustainer with an electric motor? The Gizmotron proves this is possible even if their device was never popular and had some problems. You really just need some way to get the strings vibrating. Here’s a video of Van Halen using an electric drill as a slide. The spinning action of the chuck is obviously creating some of the sound. Many times the simple solution is the best. There’s probably many off the shelf products that double as sustainers. Here’s the Lips from Anvil using a Dildo. Of course anything that effects the length of the string will effect the pitch. This has been done a few times by various others.
Not sure what else to say on the subject. It seems ripe for experimentation. If you don’t fancy expensive Moog guitar you can probably whip up your own sustainer from parts around the house!