Yamaha CC-50 - Manual (Page 5)

ACTIVE SERVO TECHNOLOGY
Active Servo
Processing
Amplifier
Port
Cabinet
High-
amplitude
bass
sound
Signals of low amplitude
Negative-impedance
output drive
Air woofer
(Helmholtz resonator)
Signals
E-3
English
The theory of the Active Servo Technology is based upon two
major factors, the Helmholtz resonator and negative-
impedance drive. Active Servo Processing speakers
reproduce the bass frequencies through an “air woofer”,
which is a small port or opening in the speaker’s cabinet.
This opening is used instead of, and performs the functions
of, a woofer in a conventionally designed speaker system.
Thus, signals of low amplitude within the cabinet can,
according to the Helmholtz resonance theory, be output from
this opening as waves of great amplitude if the design is such
that the size of the opening and the volume of the cabinet are
in the correct proportion to satisfy a certain ratio.
In order to accomplish this, moreover, the amplitudes within
the cabinet must be both precise and of sufficient power
because these amplitudes must overcome the “load”
presented by the air that exists within the cabinet. Thus it is this problem that is resolved through the
employment of a design in which the amplifier functions to
supply the signals. If the electrical resistance of the voice coil
is reduced to zero, the movement of the speaker unit would
become linear with respect to signal voltage, and, to
accomplish this, a special negative-impedance output-drive
amplifier for subtracting output impedance of the amplifier is
used.
By employing negative-impedance drive circuits, the amplifier
is able to generate precise, low-amplitude low-frequency
waves with superior damping characteristics, and these
waves are then radiated from the cabinet opening as high-
amplitude signals. The system can, therefore, by employing
the negative-impedance output drive amplifier and a speaker
cabinet with the Helmholtz resonator, reproduce an extremely
wide range of frequencies with amazing sound quality and
less distortion.
The features described above are combined to be the
fundamental structure of the Active Servo Technology.
CAUTION 1
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.
CAUTION 2
As the laser beam used in this compact disc player is harmful to
the eyes, do not attempt to disassemble the cabinet. Refer
servicing to qualified personnel only.
Laser component in this product is capable of emitting radiation
exceeding the limit for Class 1.
PRECAUTIONS: READ THIS BEFORE OPERATING YOUR UNIT
WARNING
To reduce the risk of fire or electric shock, do not expose this unit to
rain or moisture.
To avoid electrical shock, do not open the cabinet. Refer
servicing to qualified personnel only.
This compact disc player is
classified as a CLASS 1 LASER
product.
The CLASS 1 LASER PRODUCT
label is located on the rear exterior.
(Europe and U.K. model only)
Laser Diode Properties
•
Material: GaAlAs
• Wavelength: 780nm
•
Emission Duration: continuous
•
Laser Output: max. 44.6µW*
* This output is the value measured at a distance of about 200mm
from the objective lens surface on the Optical Pick-up Block.
CLASS 1 LASER PRODUCT
APPAREIL À LASER DE CLASSE 1
PRODUCTO LASER DE CLASE 1