Attributes Of Signals - M-Audio Wayoutware TimewARP 2600 User Manual

Another way to record such a signal is, with high-speed digital circuits, to measure the underlying medium many times each
second, and store the measured numbers. This is digital recording.
Since the TimewARP 2600 is not constructed of electronic circuits, concepts such as "voltage" don't apply here. The TimewARP
2600 is software, a complex piece of computer behavior. The signal medium for the original ARP 2600 was electrical
pressure, measured in volts. The signal medium for the TimewARP 2600 is simply number sequences. We use those
numbers the way the original machine used electrical pressure; where the original Owner's Manual used the word "voltage"
we will just say "signal" or "signal level," and in the module specifications we will refer to "virtual Volts" or "vV."
3.2

Attributes of Signals

The simplest possible signal is a sine wave. It's like the back-and-forth motion of a point on a circle as the circle rotates. A
lot of the mathematics of sine waves is based on that rotating-circle idea; you don't have to get involved in that unless you're
curious about it, but it's helpful to train your imagination by picturing the basic sine-wave graph as a slightly stretched coil
spring like a "slinky."
The motion of a pendulum, or of a tuning fork, swinging back and forth as they slowly come to rest, is a decaying sine
wave.
A sine wave signal has exactly three attributes: its frequency, its amplitude, and its phase. It has no other characteristics at
all. (The decaying swing of the pendulum or the tuning fork does have one other attribute: the amount of energy/amplitude
that it loses on each swing. It's not a "pure" sine wave.)
3.2.1 Fundamental Attributes
Picture a point on that rotating circle, leaving a trail behind as it rotates, like an airplane propeller. Picture the trail, stretched
out behind like a coil spring, and ask yourself:
3.2.1.1 Amplitude: what's the diameter of this imaginary circle?
3.2.1.2 Frequency: how fast is it rotating?
3.2.1.3 Phase: when does it start a new cycle?
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TimewARP • User Guide