Kenwood DMC-J7R Service Manual

PORTABLE MD RECORDER
DMC-J7R
SERVICE MANUAL
Transparency cover *
(B10-)
Knob
(K27-2272-08)
Front cabinet
(A02-2808-08)
MD cover
(F07-1638-08)
S: Silver, B: Blue
General
Power source ........................ DC
DC 5 V (AC adaptor)
AC 230 V, 50 Hz
DC 3 V Separately available battery case
DC 4.0 V : Separately available car
Power consumption ............. 7 W (AC adaptor)
Output power ........................ RMS; 20 mW (10 mW + 10 mW)
(0.2 % T.H.D.)
Charging time ....................... Approx. 3.0 hours
(When using the AC adaptor included
with the unit)
Battery life
When using the recharge-
When using two,
able battery NB-L10A (fully
commercially available,
charged) included with the
high capacity, "AA" size,
unit
alkaline batteries (in the
separately available battery
case)
Continuous recording: Continuous recording:
Approx. 4 hours
Approx. 4.5 hours
Continuous play:
Continuous play:
Approx. 8 hours
Approx. 6.5 hours
Note:
The battery case is only sold in certain areas. For more details,
please ask your dealer.
The continuous recording time is for analogue input when the
volume level is set to "VOL 0".
The continuous play time shows the value when the volume level is
set to "VOL 15".
The above values are the standard values when the unit is charged
and used at an ambient temperature of 20
The operating time when using alkaline batteries may be different,
depending on the type and manufacturer of the batteries, and on
the operating temperature.
In compliance with Federal Regulations, following are reproduc-
tions of labels on, or inside the product relating to laser product
safety.

SPECIFICATIONS

3.6 V (rechargeable lithium-ion
battery NB-L10A x 1)
(commercially available, "AA"
size, alkaline battery x 2)
adaptor, DC-C70
(for cars with a 12-24 V DC
negative earth electrical system)
When using two, commercially
available, high capacity, "AA"
size batteries with the
rechargeable battery (fully
charged)
Continuous recording:
Approx. 8.5 hours
Continuous play:
Approx. 14.5 hours
o
C.
© 1998-6/B51-5441-00 (K/K) 3163
* Refer to parts list on page 26.
Input sensitivity
.....
Recording level Reference input level
MI C H
MIC L
LINE
Output level ...........
Specified output
Headphones —
LINE 300mV (-12dB)
Dimensions ........................... Width: 87.0 mm (3-7/16")
Height: 29.4 mm (1-3/16")
Depth: 81.5 mm (3-7/32")
Weight ................................... 219 g (0.49 lbs.) with rechargeable
battery
..........................
Input socket Line/optical digital, microphone
(powered by the main unit)
Output socket ....................... Headphones (impedance: 32
ohms)/remote control unit
MiniDisc Recorder
Type ....................................... Portable MiniDisc recorder
Signal readout ...................... Non-contact, 3-beam semi-coductor
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 - 900 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 converted to 44.1 kHz,
and then recorded.)
Unmeasurable (less than ±0.001% W.peek)
Wow and flutter ....................
KENWOOD-Crop. certifies this equipment conforms to DHHS
Regulations No. 21 DFR 1040. 10, Chapter 1, Subchapter J.
DANGER : Laser radiation when open and interlock defeated.
AVOID DIRECT EXPOSURE TO BEAM
Upper case assy
(A02-2814-08) : S
(A02-2862-08) : B
Knob base
(A02-2816-08)
Knob
(K29-2270-08)
Bottom cabinet *
(A02-)
Input impedance
0.25 mV 10 k ohms
2.5 mV 10 k ohms
100 mV 20 k ohms
Load
Maximum
output level impedance
10 mW + 32 ohms
10 mW
— 50 k ohms