Page 1
MD-MT831H/W
Ð 2 Ð
Precaution to be taken when replacing and servicing the laser pickup.
The following precautions must be observed during servicing to protect your eyes against exposure to the laser.
Warning of possible eye damage when repairing:
If the AC adaptor or batteries are connected when the top houising (disc cover) of the unit is removed, and the PLAY key is
pressed, the laser will light up during focus access (2-3 seconds). (Fig. 3-1) During the operation, the laser will leak from the
opening between the magnetic head and the mechanical chassis (Fig. 3-2). In order to protect your eyes, you must not look
at the laser during repair. Before repairing be sure to disconnect the AC adaptor and remove the batteries. Precaution to be taken when replacing and servicing the Laser Pickup.
The AEL (Accessible Emission Level) of Laser Power Output for this model is specified to be lower than Class I Requirements.
However, the following precautions must be observed during servicing to protect your eyes against exposure to the laser beam.
(1) When the cabinet has been removed, the power is turned on without a compact disc, and the Pickup is on a position
outer than the lead-in position, the Laser will light for several seconds to detect a disc. Do not look into the Pickup Lens.
(2) The Laser Power Output of the Pickup inside the unit and replacement service parts have already been adjusted prior
to shipping.
(3) No adjustment to the Laser Power should be attempted when replacing or servicing the Pickup.
(4) Under no circumstances look directly into the Pickup Lens at any time.
(5) CAUTION - Use of controls or adjustments, or performance of procedures other than those specified herein may result
in hazardous radiation exposure.
SAFETY PRECAUTION FOR SERVICE MANUAL
CAUTION
Laser Diode Properties
lMaterial: GaAIAs
lWavelength: 785 nm
lPulse time:
Read mode; 0.8 mW Continuous
Write mode; max. 10 mW 0.5S
min. cycle 1.5S
Repetition lThis Portable MiniDisc Recorder is classified as a CLASS 1 LASER product.
lThe CLASS 1 LASER PRODUCT label is located on the bottom.
l
Use the Portable MiniDisc Recorder only in accordance with the instructions given in
this manual and do not attempt to interfere with the interlock switch or make any
other adjustment as this may result in exposure to hazardous radiation.
LASER KLASSE 1
LUOKAN 1 LASERLAITE
KLASS 1 LASERAPPARAT
(MD-MD831H for U.K.)
(MD-MD831H for Europe) (For MD-MD831W)
VAROITUS! LAITTEEN KÄYTTÄMINEN MUULLA KUIN TÄSSÄ KÄYTTÖOHJEESSA
MAINITULLA TAVALLA SAATTAA ALTISTAA
KÄYTTÄJÄN TURVALLISUUSLUOKAN 1 YLITTÄVÄLLE
NÄKYMÄTTÖMÄLLE LASERSÄTEILYLLE.
VARNING - OM APPARATEN ANVÄNDS PÅ ANNAT SÄTT ÄN I DENNA BRUKSANVISNING
SPECIFICERAS. KAN ANVÄNDAREN UTSÄTTAS FÖR OSYNLIG LASERSTRÅLNING, SOM
ÖVERSKRIDER GRÄNSEN FÖR LASERKLASS 1.
(MD-MD831H for Europe)
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MD-MT831H/W
Ð 3 Ð
FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER TO
THE OPERATION MANUAL.
SPECIFICATIONS
Specifications for this model are subject to change without prior
notice
lThe continuous recording time is for analogue
inputs when the volume level is set to VOL 0.
lThe continuous play time shows the value
when the volume level is set to VOL 15.
lThe above values are the standard values
when the unit is charged and used at an ambi-
ent temperature of 20°C (68°F).
lThe operating time when using an alkaline
battery may be different, depending on the type
and manufacturer of the battery, and on the
operatin
g temperature.Dimensions:
Width: 79.4 mm (3-1/8")
Height: 17.9 mm (11/16")
Depth: 81.8 mm (3-3/16")
Weight:
163 g (0.36 lbs.) with rechargeable battery
Input socket:
Line/optical digital, microphone (powered by
the main unit)
Output socket:
Earphones (impedance: 32 ohms)/remote
control unit
nMiniDisc Recorder
Type:
Portable MiniDisc recorder
Signal readout:
Non-contact, 3-beam semi-conductor laser
pick-up
Audio channels:
Stereo 2 channels/monaural (long-play mode)
1 channel
Frequency response:
20 - 20,000 Hz (± 3 dB)
Rotation speed:
Approx. 400 - 1,350 rpm
Error correction:
ACIRC (Advanced Cross Interleave Reed-
Solomon Code)
Coding:
ATRAC (Adaptive Transform Acoustic Coding),
24-bit computed type
Recording method:
Magnetic modulation overwrite method
Sampling frequency:
44.1 kHz (32 kHz and 48 kHz signals are con-
verted to 44.1 kHz, and then recorded.)
Wow and flutter:
Unmeasurable (less than ±0.001% W. peak)
nGeneral
Power source:
DC 3.6V:Rechargeable Lithium-Ion battery
x 1
DC 5.0V: AC adaptor (AC 220 - 230V, 50/
60 Hz) [MD-MT831H for Europe]
DC 3.3V:Battery case (with voltage booster)
(commercially available, AA
size, alkaline battery x 1)
DC 4.5V: Separately available car adaptor,
AD-CA20X (for cars with a 12-
24V DC negative earth electrical
system)
Power consumption:
7 W (AC adaptor) [MD-MT831H]
Output power:
RMS; 20 mW (10 mW + 10 mW) (0.2% T.H.D.)Charging time:
Approx. 3 hours
(When using the AC adaptor included with the
unit)
Battery life:
When using the rechargeable battery (fully
charged) included with the unit
Continuous recording:Approx. 9.5 hours
Continuous play:Approx. 14.5 hours
When using one, commercially available, high
capacity, AA size, alkaline battery (The re-
chargeable battery is in the unit, discharged.)
Continuous recording:Approx. 4.5 hours
Continuous play:Approx. 11.5 hours
When using one, commercially available, high
capacity, AA size, alkaline battery with the re-
chargeable battery (fully charged)
Continuous recording:Approx. 14 hours
Continuous play:Approx. 26 hoursOutput level:
Specified
outputMaximum
output levelLoad
impedance
Earphones
- 10 mW +
10 mW32 ohms
LINE
250 mV
(-12dB)- 10 k ohms
Input sensitivity:
Recording
levelReference input
levelInput
impedance
MIC H 0.25 mV 10 k ohms
MIC L 2.5 mV 10 k ohms
LINE
100 mV 20 k ohms
DC 5.0V: AC adaptor (AC 230 - 240V, 50/
60 Hz) [MD-MT831H for U.K.]
DC 5.0V: AC adaptor (AC 110 - 240V, 50/
60 Hz) [MD-MT831W]
0.15A (AC adaptor) [MD-MT831W]
Figure 3-1 Figure 3-2
Magnet head
Optical pickup
Top Cabinet
Magnet Head
Laser Beam
Optical Pickup
Main PWB Spindle motor Mechanism
Chassis
