| |
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| Active circuit |
|
Electrical device with a power-level
gain. |
| Active component |
|
An electrical or electronic element
capable of controlling voltages or currents to produce gain or
switching action in a circuit (e.g., transistor, vacuum tube,
or saturable reactor). |
| Active mixer |
|
A device containing amplification
for signal gain which combines two or more electrical signals
into a single output. |
| Additive synthesis |
|
The electronic production of audio
signals by means of combining several signals, often sine tones
which are integer multiples of a fundamental frequency. Example
a Hammond B-3 is additive. |
| ADSR |
|
|
| Alternating current (AC) |
|
A flow of electricity which reaches
maximum in one direction, decreases to zero, then reverses itself
and reaches maximum in the opposite direction . ( positive to
negitive, negitive to positive) |
| Alternating current frequency |
|
The number of cycles per second of
an alternating
current. (standerd US frequency is 60 Hz) |
| Ampere (amp) |
|
A unit of electrical current or rate
of flow of electrons. One volt across · ohm of resistance
causes a current flow of 1 ampere. |
| Amplification |
|
Increase in size of a medium
in its transmission from one point to an
other. Increase the volume on an audio signal. |
| Amplifier |
|
A device which draws power from a
source other than the input signal and which produces as an output
an enlarged reproduction of the essential features of the input. |
| Amplitude |
|
The magnitude of variation in a changing
quality from its zero value. |
| Amplitude modulation |
|
Modulation in which the amplitude
of a wave is the characteristic that is subject to variation.
(like putting an LFO to control the VCA's output) |
| Analog |
|
A circuit that produces a continuosly
changing electrical signal |
| Attack |
|
Those amplitude characteristics having
to do with the beginning of a sound or signal . |
| Attack transients |
|
Short duration, nonrepetitive sound
events taking place during the
beginning of a sound or signal. |
| Audio generator |
|
An electronic device which produces
complex (nonsinusoidal) sig
nals at frequencies between 20 and 20,000 Hz. (The terms oscillator
and generator are frequently used interchangeably, but in correct
usage oscillator refers to a device that produces sine waves
and generator refers to a device that produces waves other than
sine waves.) |
| Bandpass filter |
|
A wave filter with a single transmission
band, neither of the cutoff
frequencies being zero or infinite. The filter attenuates frequencies
on either side of the band. |
| Band-reject filter |
|
A filter having a single attenuation
band, with neither of the cutoff
frequencies being zero or infinite. |
| Bandwidth |
|
The range within the limits of a
band. The width of a bandpass filter is generally taken as the
limits between which its attenuation is not more than 3.0 decibels
greater than its average attenuation throughout its passband. |
| Beats |
|
Periodic variations that result from
the superimposition of waves having different frequencies. |
| Center frequency |
|
The average frequency of a band of
frequencies. |
| Channel |
|
A single path for transmitting electric
signals. |
| Closed circuit |
|
An electric circuit through which
current may now when a voltage is applied. |
| Combination tone |
|
A difference tone or summation tone.
Frequencies produced in a
nonlinear device, such as in the ear or an audio amplifier having
appreciable harmonic distortion. |
| Control input |
|
Terminals or other places where a
control signal may be applied to a circuit or device to modify
its action. |
| Control signal |
|
A signal which when introduced at
a control input may be used to
modify the action of another circuit or device. |
| Current |
|
The movement of electrons through
a conductor. |
| Cutoff frequency |
|
The frequency above or below which
a selective circuit fails to re
spond . |
| Decay |
|
Those amplitude characteristics having
to do with the ending of a sound or signal. |
| Decibel (db) |
|
The standard unit of loudness. |
| Difference tone |
|
A tone produced in a nonlinear system
whose frequency is the difference between the frequencies of
two tones sounding together. |
| Direct current (DC) |
|
An essentially constant value current
that flows only in one direction. |
| Echo |
|
A delayed repetition (sometimes several
rapid repetitions) of the original sound or signal. |
| Envelope |
|
Those amplitude characteristics having
to do with the attack, steady state and decay of a sound or signal.
The loudness of a sound or signal with respect to time. |
| Envelope follower |
|
A device which produces changing
DC voltages which are a replica of the envelope of an AC signal
present at another input of the same device. |
| Envelope generator |
|
A device which generates a DC voltage
varying with time, usually set by dials on the face of the device.
The DC voltage is appropriate for control of voltage-controlled
amplifiers, voltage-controlled filters and voltage-controlled
oscillators. |
| Equalization |
|
The process of reducing the frequency
and/or phase distortion of a circuit by the introduction of networks
to compensate for the difference in attenuation and/or time delay
at the various frequencies in the transmission band. |
| Feedback circuit |
|
A circuit which returns a fraction
of the output to the input. |
| Filters |
|
A selective network of resistors,
inductors or capacitors which offers comparatively little opposition
to certain frequencies, while blocking or attenuating other frequencies. |
| Fixed bandpass filter |
|
A bandpass filter which is set at
a particular frequency. |
| Formant spectrum |
|
The particular frequency region or regions in
which the energy of
the partials of a sound is most concentrated. |
| Frequency |
|
The number of recurrences of a periodic phenomenon
in a unit of time. |
| Frequency modulation |
|
Modulation in which the frequency of a wave is
the charac
teristic that is subject to variation. |
| Full wave |
|
A sound wave consisting of one complete cycle
of compression and rarefaction; an electrical wave consisting
of one complete cycle of positive and negative alternation. |
| Function |
|
A specific purpose of an entity, or its characteristic
action. |
| Fundamental frequency |
|
The principal component of a wave; i.e., the
component
with the lowest frequency or greatest amplitude. |
The
Audio Playground Synthesizer Museum.