Philips N4450 - Technical Features

3. TECHNICAL FEATURES
3.1. Hi-Fi QUALITY
The amplifier section of N 4450 as well as the recording
section at the tape speeds 19 and 9.5 cm/sec. amply com-
plies with the requirements of the Hi-Fi standard DIN
45 500. This DIN standard imposes very strict requirements
as regards tape speed accuracy, frequency range, signal/noise
ratio, distortion of the amplifier etc. The recorder has been
designed for the use of Philips’ high-output low-noise tapes
which also come up to the above-mentioned DIN-standard.
For best results it is therefore recommended to use only
this tape on your N 4450 recorder.
3.2. AUTOMATIC REVERSE
The recorder features an “automatic reverse system”. This
means that, unlike most other tape recorders, the tape can
run from left to right as well as from right to left. When the
reverse system is operative, the tape after running from left
to right, is automatically reversed by a strip of switching
foil at the end. When the tape subsequently reaches the other
end, the recorder is stopped.
Automatic reverse operation is possible during playback and
recording. The direction can also be changed before the end
of tape is reached by pressing one of the keys “<] LEFT”(16)
or “RIGHT> ” (19).
3.3. SIX HEADS
The recorder is provided with a total of 6 magnetic heads.
For each tape transport direction a separate head system is
provided, each comprising an erase head, a recording head and
a playback head. Instead of the usual combined recording/
playback head, this recorder has a separate head for recording
and for playback. The main advantage of this is that the two
heads can be specially designed for their specific function,
giving optimum results both for recording and playback.
Another advantage is that due to the separate recording and
playback heads and preamplifiers echo and reverberation
recordings can be made (see 2.5.) and so-called after-tape
monitoring (see 3.4.) is possible.
3.4. BEFORE AND AFTER TAPE MONITORING
During recording, the signal can be monitored in two ways:
1. Before-tape monitoring. With switch (10) in position “B”,
the signal to be recorded is fed from the recording amplifiers
to the. recording-level indicators, to the sockets for connection
of headphones and monitor amplifier and to the output
amplifiers. This allows monitoring of the signal to be recorded
before it is actually recorded on the tape.
2. After-tape monitoring. With switch (10) in position “A”,
the playback head scans the signal just recorded by the re-
cording head and feeds it to the playback preamplifiers, the
recording level indicators, the sockets for connection of
headphones and monitor amplifier and finally to the output
amplifiers. This permits you to check the result (the recording
just made).
3.5. CUEING
To prevent unnecessary wear of the tape and the heads, the
tape is lifted clear of the heads during fast winding, so that
nothing is heard.
However, if during fast winding one of the cueing buttons
(5) is depressed (which one depends on the direction of
58
recording),
the
tape
is
applied
to
the
heads
and
the
recording
becomes
audible.
Although
the
high
winding
speed
and
changed
pitch
make
it
sound
very
unusual,
you
will
however
be
able
to
recognise
characteristic
parts
of
the
recording
after
some
practising.
This
makes
it
possible
to
stop
the
tape
at
these
points.
The
possibility
of
varying
the
winding
speed
with
the
speed
control
(15)
may
also
be
convenient
in
rapidly
locating
a
certain
passage
on
the
tape
during
cueing.
3.6. THREE MOTORS
The
recorder
is
fitted
with
three
motors.
Two
motors
serve
for
driving
the
two
reel
discs
and
the
third
one,
a
special
so-called
“‘Hall”-motor,
drives
the
two
capstans
and
thus
the
tape
during
playback
and
recording
on
both
directions.
The
use
of
one
separate
motor
for
the
tape-transport
functions
during
recording
and
playback
ensures
a
high
accuracy
and
reliability.
The
two
motors
for
the
reel
discs
ensure
a
high
winding
speed
during
fast
winding.
In
order
to
avoid
a
complex
mechanical
drive
system,
most
of
the
functions
are
electro-magnetically
controlled
by
means
of
relays.
3.7. 26.5-cm REELS
This
recorder
accepts
reels
with
a
diameter
up
to
26.5
cm.
The
use
of
plastic
reels
is
preferred,
as
the
recorder
has
been
designed
for
this.
Metal
reels
are
heavier
than
plastic
reels
and
may
therefore
cause
problems
when
starting
and
stopping.
Due
to
the
difference
in
tractive
power
required
between
large
and
small
reels
the
recorder
is
provided
with
a
reel
selector
switch.
3.8. TAPE TENSION COMPARATORS
To
the
left
and
right
of
the
tape
slot
(6),
two
tape
tension
comparators
(4)
and
two
guide
rollers
are
fitted.
Through
a
special
mechanism
the
tape
tension
comparators
maintain
a
constant
tape
tension
during
playback,
recording
and
fast
winding.
The
rotating
guide
rollers
ensure
that
the
tape
is
precisely
guided
along
its
path.
3.9.
PROGRAMME
INDICATOR
WITH
PRE-SELECTOR
The
programme
indicator
and
the
pre-selector
(3)
coupled
to
it
facilitate
the
rapid
location
of
a
certain
recording
on
the
tape.
When
the
programme
indicator
is
set
to
“0000”
at
the
beginning
of
the
tape
and
the
reading
is
taken
at
the
beginning
and
end
of
a
recording,
this
or
another
number
can
be
set
on
the
pre-selector.
The
tape
is
then
automat-
ically
stopped
when
the
programme
indicator
has
reached
the
pre-selector
setting.
This
pre-selection
facility
is
operative
when
the
tape
runs
to
the
left
and
to
the
right
and
can
be
used
during
playback
as
well
as
fast
winding.
However,
during
recording
the
device
is
inoperative
to
prevent
erroneous
interruptions.
3.10. TIMER
The
recorder
incorporates
a
special
timer
(39),
which
allows
recording
or
playback
to
be
started
or
stopped
automatically
at
a
preset
time.
At
the
timer
you
can
set
the
correct
time
and
the
desired
starting
and
stopping
time.
When,
for
instance,
for
a
recording
one
of
the
start
keys,
the
record
key
and
the
pause
key
are
pressed,
recording
is
started
and
stopped
at
the
preset
times.
This
feature
permits
you
to
record
for
example
a
radio
programme
in
your
absence.