Denon DR-M22 - Disassembly Instructions

DOLBY C NOISE REDUCTION SYSTEM
™ The Dolby noise reduction system substantially reduces the tape background noise (hiss) in-
herent
in
the
cassette
medium.
Dolby
B
NR
is
most
widely
in
use.
However,
Dolby
C
NR
is
a
much
more
recent
development
and
represents
a
significantly
improvement
over
Dolby
B
NR.
m™ Tape background noise consists primarily of high freqnency information which is particularly
annoying
during
soft
passages.
The
Dolby
NR
system
increases
the
level
of
low
volume
mid
and
high
frequency
signals
during
recording
and
reduces
the
level
of
these
signals
by
an
identical
amount
during
playback.
As
a
result,
the
playback
signal
is
identical
to
the
original
source
-
signal,
but
the
level
of
background
noise
generated
by
the
tape
is
greatly
reduced.
™@ The operating principle of Dolby C NR is similar to that of B except for the encoding/decoding
response
curves.
The
noise
reduction
effect
obtained
by
Dolby
C
NR
is
up
to
20dB,
compared
to
10dB
with
Dolby
B
NR.
In
addition,
Dolby
C
NR
uses
an
antisaturation
network
and
spectral
skewing circuitry, and significantly improves the dynamic range in the mid to high frequencies.
BK 10K 20K 40K “0 20 H 60 100 200
Fig. 7 . Fig. 8
AUTO TAPE SELECT FEATURE
This Stereo Cassette Deck contains an Auto Tape Select feature which automatically selects
the optimum bias and equalization for the tape in use. This is accomplished by detection of tape
type detection holes in the cassette housing. The Tape type (NORMAL, CrO2, or METAL) is
indicated by the TAPE SELECT indicator.
KNEW DX7
if a tape without tape type detection holes is
used, the TAPE SELECT indicator will not indi-
cate the correct tape type and the deck will
automatically adjust itself for norma! tape.
NEW DX8
UD I XLII
MAXELL XLi XLS MX
XLIS
SA MA
SA-X MA-R
FUJI FR METAL
BX
AHF Paes
Detection holes
for chrome tape
If the deck is switched on with no cassette
loaded, the TAPE SELECT indicator will show
“MET AL". ¢ Typical tape brands for each type are listed
in the above table. There may be a differ-
MFeCr tape ence in sensitivity of a few decibels between
Since the Auto tape Select feature does not tape brands.
have a separate position for FeCr tape. FeCr ¢ This Cassette Deck is optimally aligned for
tape is not recommended to use on this deck. tapes marked with “><”.
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