Akai M-10 User Manual

ll.
MEASURING
METHOD
TAPE SPEED DEVIATION
1. Method involving use of pre-recorded tape.
For measuring the tape speed diviation, play back the
pre-recorded tape at 1,000Hz+ 0.1%. Connect the
appropriate output to a frequency counter meter in
order to measure the tape speed deviation from the
resulting deviation of the measured frequency.
2. Method involving use of timing tape. (designed for
tape speed measurement)
This method utilizes a timing tape marked at intervals of
7-1/2”. The running time of over 60 marked sections of
tape is measured in order to calculate the deviation of
the tape speed. In applying this method, however, it
should be kept in mind that the timing tape stretch or
contract measurement enor is inevitable, so that it is
necessary to measure the total length of the tape in
advance.
WOW AND FLUTTER
Playback the 3,000 Hz pre-recorded tape of which the
wow and flutter level is guaranteed to be smaller than
0.07% for measurement by means of a wow meter. It is
also possible for a 3,000 Hz sine wave to be recorded
and played for measurement by means of the wow
meter. In this case, however, the wow meter indicates a
value as much as twicc the value given in the specifi-
cations on the first page.
FRQUENCY RESPONSE
RECORD :
1) Give a sine wave of 1,000 Hz to the Line Input of
the recorder to be tested through an attenuator
from an audio frequency generator.
2) Set the Record/Playback Knob to “Rec” position
and adjust the line input volume so that the VU
Meter needle indicates “O”’ VU.
3) Set the Equalizer Switch to 7-1/2” or 3-3/4”
position.
4) Under the condition described in (2), lower the
input level 16 db by means of the attenuator.
5) Record the spot frequency in the range of 30 Hz to
25,000 Hz from the audio frequency generator.
PLAYBACK :
6) Set the Record/Playback Knob to “Play” position.
7) Connect a Vacuum Tube Volt Meter to the Line
Output Jack. (VTVM with milli volt scale.)
8) Playback the reocrded tape.
9) Playback the recorded spot frequencies and make a
memo of output level and plot the value on a graph.
Mic. input
Oscillator
Microphone Line output jack
TOTAL HARMONIC DISTORTION FACTOR
1 KHz
Distortion
meter
Audio
Oscillator
Connect
the
measuring
instrument
as
shown
above,
and
record
the
1,000
Hz
sine
wave
at
“O”
VU.
Playback
the
resulting
signal
and
measure
the
overall
distortion
factor.
Measure
the
noise
level
of
the
tape
recorder
with
the
tape
removed
;
connect
the
audio
oscillator
directly
to
the
distortion
meter
for
measurement
of
the
distortion
factor
of
the
oscillator.
The
required
distortion
factor
may
be
obtamed
from
the
results
of
the
above
measuement
by
the
following
formula
:
do=d-di_ dz
where, do = Required
d = Overall distortion factor
di = Noise level
d2 = Distortion factor of the oscillator
(Note
:
New
tape
of
particularly
good
quality
should
be
used for measurement of the distortion factor.)
SIGNAL TO NOISE RATIO
M-10
Set the Equalizer Switch to “7-1/2 ips” position and
playback a tape containing a 25 Hz sine wave recorded
at “O” VU level on a standard recorder. Connect a
V.T.V.M. to the line output jack of the recordir and
measure its output. Then remove the tape and measure
the noise level under the same condition. Convert into
decibels each of the measured values.

Akai M-10 Specifications

General

Brand	Akai
Model	M-10
Category	Tape Deck
Language	English