Dual C 810 Bedienungsanleitung Seite 13

connect the other end of the adapter to the tape recorder or
cassette recorder, merely connect the adapter cord to the
appropriate socket.
Microphone Recordings
The HiFi stereo cassette deck is fitted with a jack for low and
medium impedance microphones with values between 200 and
1000 Ohms and a 1/4 coaxial plug.
For this we recommend the HiFi-Electret capacitor microphones
Dual MC 304 and Dual MC 316.
The microphone connected to jack (21) automatically records
on both tracks.
Stereo microphone recording is possible by means of the 5-pole
DIN jack.
Erasing
The cassette deck erases all previous recordings when a new
recording is made. If you want to erase a recording without
making a new one, play the cassette through with the controls
set for "recording" but with all controls set to 0"
All compact cassettes have two slots on their rear edge which
are partially covered by plastic tabs. You can prevent accidental
erasure of your own recordings by breaking out the appropriate
tab.
Pre-recorded tapes bought from cassette dealers are usually al-
ready protected against accidental erasure by removal of the
tabs.
If you wish to record on a tape protected in this way it is only
necessary to close the slots temporarily by means of a small
piece of adhesive tape.
Please note that the additional slots present in Cr02 tapes must
not be closed by adhesive tape.
Technical Data
Drive
The precision DC motor is fitted with an integrated frequency
generator and modern control IC for speed regulation. The
Dual decoupling motor suspension provides propagation of
vibration and running noises.
A precision made flat belt drives the capstan and thereby plays
its part.in the overall excellence of the wow and flutter charac-
teristics. The tape take-up torque receives its drive via a second
belt direct from the motor so that disturbances such as differen-
ces in cassette winding have no effect on the tape transport.
For the fast wind facility a functionally reliable gear drive is
used. This guarantees trouble-free winding even for older cas-
settes.
An electronic circuit continuously monitors tape movement
and prevents formation of loops in the tape. At the same time
it also provides the signals for auto stop. This function is inde-
pendent of the cassette or tape switching foil
Careful tape location and precise azimuth setting ensure opti-
mum treble reproduction and prevent level fluctuation
Heads
The built-in 2/4-track hard Permalloy sound head provides
excellent magnetic properties for recording and playback in
conjunction with high resistance to wear.
Compact Cassette System
Your HiFi stereo cassette deck uses a 2/4-track format. Four
tracks are provided across the full width of the tape so that two
stereo tracks are available in each direction of play and thus
the tape length is used for double stereo playing time.
Cassettes recorded in stereo on your cassette deck can also be
played on mono cassette recorders. That is to say, stereo casset-
tes are fully compatible with mono cassettes.
Maintenance and service
From time to time it is desirable to clean the heads, capstan,
pressure rollers and tape guides. For this purpose, the cover (3)
can be removed (Fig. 3). For cleaning use a linen cloth or cot-
ton swab (e.g. Q-tips) moistened with alcohol. Never use metal
instruments or touch the head surface with your fingers.
Since all the points that require lubrication have been generously
supplied with oil your recorder will work for many years under
normal conditions without trouble. Please do not try to lubri-
cate the recorder yourself. Special lubricants are needed and
lubrication and other kinds of service should only be provided
by a qualified technician or an authorized factory service agency.
Correction of Faults
If your cassette deck should give any trouble please check
whether the cause may perhaps lie in incorrect operation. The
following table may be of help. In the case of any faults which
appear inexplicable your HiFi dealer or the nearest Dual ser-
vice operation should be consulted ("possible cause or correction
of the fault).
The unit cannot be switched on.
* Power supply is interrupted, plug not properly pushed
home
* Power switch (1) not depressed.
Equipment switches off one or two seconds after switching on.
* Cassette is producing too much friction, turn it by hand
a little further or rewind (pp (9), «4 (5)). If this does
not help, tap the cassette on the table top.
. * In inserting the cassette the tape has got behind the cap-
stan ~
Tape does not start even though the take-up indicator (8) is on.
* PAUSE key (10) is depressed.
Playback level varies in pitch
* Cassette sticking or overfilled. Wind forward a little by
hand
Dust and tape abrasion is dirtying the pressure roll
Cleaning is described in the section "Maintenance and
Service"
No reproduction through the amplifier although the headphones
work properly.
* Adapter connection to the amplifier broken or wrongly
connected
RECORD key (4) cannot be depressed
* Tabs in the cassette have been broken off as described on
page 15
Your own recording is distorted.
* The distortion is in the recording source.
The heard is dirty (see Section "Maintenance and Service")
* The tape selection switch (13) is not set for the type of
tape used
Your own recordings are noisy.
* Tape is too badly worn
* DOLBY NR (15) was not depressed
Old recordings were not completely erased.
* The erase head is dirty (see section "Maintenance and
Service")
Technical Data
Tape speed 4.75 cm/s
Deviation from correct speed 10.7%
Flutter and wow
Weighted RMS + 0,045 %
To DIN for reproduction only +0,09 %
To DIN for recording/reproduction +0,13 %
Frequency response (ref. to DIN tolerances)
Standard Fe tape 20 — 16,000 Hz
Cr02 tape
20 — 16,500 Hz
FeCr tape 20 — 17,000 Hz
Signal-to-noise-ratio (weighted)
With Dolby NR
Fe 63 dB
Cr02 63 dB
FeCr 66dB