Pioneer CT-W701R Service Manual

10.
CIRCUIT
DESCRIPTIONS
@
SOUND
EQ
CIRCUIT
10.1 Purpose
More
and
more
people
are
recording
their
favorite
music
onto
cassette
tapes
and
then
listening
to
them
using
a
portable
stereo
or
car
stereo.
However,
when
a
tape
recorded
in
the
normal
way
on
conventional
equipment
is
played
back
through
a
portable
stereo
or
car
stereo,
the
low
and
high
frequency
ranges
are
often
not
strong
enough
due
to
the
characteristics
of
the
headphones
or
the
in-car
environment.
The
new
Sound
EQ
function
boosts
the
level
of
these
frequencies
by
altering
the
frequency
characteristics
of
the
music
signal
during
recording.
This
allows
users
to
produce
tapes
that
have
sonic
characteristics
ideal
for
playback
on
portable
stereos
or
car
stereos.
10.2 Operation
Operation
is
a
simple
as
setting
the
SOUND
EQ
switch
to
either
PORTABLE
or
CAR,
as
appropriate,
before
beginning
recording.
When
the
setting
is
made,
the
indication
PORTABLE
or
CAR
appears
on
the
fluorescent
counter
display
for
a
few
seconds
and
the
level
meter
changes
to
show
the
frequency
curve.
10.3 Features
*
The
frequency
characteristics
of
the
line
input
are
changed
to
match
the
requirements
of
portable
stereos
or
car
stereos.
This
has
no
adverse
effects
on
S/N
ratio
or
distortion
levels.
¢
When
Sound
EQ
is
combined
with
BLE,
compensation
for
the
tape’s
specific
characteristics
can
be
performed
before
recording
optimized
for
portable
stereos
or
car
stereos
takes
place.
This
ensures
that
the
amount
of
boost
will
not
vary
from
one
cassette
to
another,
allowing
the
creation
of
even
more
effective
tapes.
20 30 100 200 500
CT-W801R, CT-W851R, CT-W701R’
10.4 Recording Frequency Compensation
for Car Stereo Applications
There are many restrictions on where and how speakers can be
installed in a car due to the complex configuration of the car
interior and its small capacity of around 3 m quite small
compared with a normal audio listening room. Under these
circumstances, car speakers tend to have small-di-ameter
diaphragms. Also, depending on the details of the installation,
there may be a great deal of noise that leaks in from behind the
speakers. Both of these factors work against the effective
reproduction of low frequency sounds.
In addition, the sound spectrum of the noise produced when a
car is running shows an increase in intensity at the low end of the
frequency range. This low range noise tends to mask the
bassportion of the music being played through the speakers. In
order to improve the low frequency characteristics peculiar to
cars, Sound EQ boosts the level of a frequency band centering on
the frequencies between 40 and 50 Hz.
There is also a tendency for treble reproduction to be insufficient
in card due to poor speaker orientation and the presence of
objects such as seats that absorb high frequency sounds. To
compensate for this, a slight boost in the high range is also added
in order to create a sense of increased spaciousness,
10.5 Recording Frequency Compensation
for Portable Stereo Applications
The headphones used with portable stereos can not match the
bass response of full-sized room speaker systems due to factors
such as the smallness of their driver diaphragms, the point at
which the electrical music signal is converted int) sound waves.
To compensate for this, Sound EQ boosts the frequencies
centered around 70 Hz. Also, the high frequeny reproduction
characteristics of headphone stereos are generdly inferior to
those of standard cassette decks due to factors such as head
azimuth misalignment, which can easily occurif the unit is
dropped or bumped. To compensate for this, a slight boost in the
high range is also added to provide added ambience.
1000 2000 5000 10000
FREQUENCY RESPONSE (LINE) MPX ON
iL

Pioneer CT-W701R Specifications

General

Track System	4-track, 2-channel stereo
Frequency Response (Metal Tape)	20 Hz - 20 kHz
Tape Type	Normal, Chrome, Metal
Type	Double Cassette Deck
Heads	2 x playback
Input	Line In
Output	Line Out
Inputs	Line In: 80 mV
Outputs	Line Out: 0.5 V
Power Supply	AC 220-240 V
Signal to Noise Ratio	70 dB
Signal-to-Noise Ratio	70 dB
Wow and Flutter	0.08% (WRMS)
Wow and Flutter (WRMS)	0.08%