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How an Ebow works..
I've seen a lot of interesting misconceptions about how the ebow
works and how "best" to use it since it was introduced in the late
1970s...
Here's my simple explanation:
What an Ebow consists of:
The Ebow is a very simple device consisting of a pickup, an amplifier
and an output coil. The pickup is essentially the same as an
electric guitar pickup, it uses a coil of wire and a magnetic pole
piece. The only difference is that the coil is wound on a single
small round bobbin and designed only to pick up the vibration of a
single string.
The pickup is connected to a very small amplifier which in turn
drives the output coil. The amplifier is not very powerful and is
easily driven into square wave clipping, which is plainly audible in
an electric instrument when the excitation coil is positioned above
the instrument's own pickup.
The pickup coil and output coil are positions at opposite ends of the
"string channel" along the bottom surface of the Ebow's body.
How an Ebow works:
The pickup in the Ebow operates exactly the same as the pickup in
every ordinary electric guitar: The string vibrating in close
proximity to the pickup causes fluxuations in the permanent magnetic
field around the pickup's coil.
These fluxuations in the magnetic field induce a voltage into the coil.
This voltage is amplified and sent to the output coil, which operates
in reverse of the pickup: The voltage sent to the output coil by the
amplifier generates a changing magnetic field which excites the
string.
Since the signal feeding the pickup and produced at the output are
from the same string a feedback loop is created, allowing the string
to ring indefinitely.
An Ebow will work on any vibrating magnetic object which is sensitive
enough to be driven by the relatively weak excitation signal.
I hope that this clarifies a few things and opens the possibilities
for all you loopers..
-Chuck Zwicky
--
...
http://www.zmix.net
http://www.esession.com/ChuckZwicky
http://albumcredits.com/zmix