Teac A-4010GSL - Level Variations and Signal to Noise Ratio (Record)

LEVEL VARIATIONS
OVERALL
Using
Scotch
#203
test
tape,
recorded
at
the
specified
level
setting
with
BIAS
switch
in
HIGH
position,
during
record/playback
the
output
level
variations
should
not
exceed
those shown
in
the
below
chart.
7-1/2ips:
0.5dB
at
400Hz
1.0dB
at
10kHz
3-3/4ips:
1.0dB
at
5kHz
Fig. 6-14 tati
SIGNAL
TO
NOISE
RATIO
8
Level
Variation
IMPORTANT:
Clean
and
demagnetize
the
heads
before
proceeding.
It
is
extremely
important
that
all
tests
described
in
the
proceeding
paragraphs
have
been
completed
and
that
all
controls
adjusted
are
left unaltered.
1.
Thread
a
record
test
tape
(Scotch
#203)
on
the
unit.
2.
Remove
the
AF
oscillator
from
the
LINE
IN
jacks.
3.
Place
the
unit
in
the
record
mode
with
no
signal
applied.
BIAS,
EQ/LEVEL
switch
in
HIGH
position.
NOTE:
Noise
readings,
when
taken
while
recording,
may
be
affected
by
the
bias
signal
which
could
be
leakings
through.
It
is
there-
fore
good
practice
to
rewind
the
no
signal
recorded
section
and
take
the
noise
reading
during
playback.
4.
Note
the
point
on
the
index
counter
where
recording
begins.
5.
Rewind
the
tape
and
play
it
back.
6.
The
noise
level
as
indicated
on
the
level
meter
should
be
-55
dB
or
less.
This
is
equivalent
to
a
47
dB
signal
to
noise
ratio
at
oper-
ating
reference
level.
NOTE:
Bias,
erase
and
playback
amplifier
noise
are
all
included
in
in
this
measurement.
All
frequencies
between
40
Hz
and
15
kHz
are
measured unweighted.
a
ee el 0 a
ne
I ANA
Hl at NU
eae
re
me
T
SES
eer
TTT
CC
A
SOK
FREQUENCY
IN
Hz
10-0343
Fig. 6-13 EQ. Curves -Record-