Onkyo TA 2048 Service Manual

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TA-2048

OM-3234
STEREO CASSETTE
TAPE IECK
MODEL TA-2048
Black and silver model
UDN, UDCS UD 120v AC, 60Hz
UG 220v Ac. SOHz
uw I20 or 220v Ac, 50/60Hz
UQA, UQB 240v Ac. 50H;
SPECIFICATIONS
SAFTY-RELATED COMPONETN WARNINGI! Tmck Fomm: 4 tracks, 2 channels
COMPONENTS IDENTIFIED BY MARK A 0N Erasing System: AC erase
THE SCHEMATIC DIAGRAM AND IN THE PARTS Tape Speed: 4.8 cm/sec. (1-7/8 mm.)
LIST ARE CRITICAL FOR RISK OF FIRE AND W0w& Flutter: 0.045%(WRMS)
ELECTRIC SHOCKI REPLACE THESE com, Frequency Response: 20-17,000 Hz (SO-16,000 Hz : 3dB)
PONENTS WITH ONKYO PARTS WHOSE PARTS (normal position tape)
NUMBERS APPEAR AS SHOWN IN THIS MANUAL 20-18900 HZ (30-11000 Hz 1 3dB)

(high position tape)
20-19,000 Hz (30-18900 Hz 1 3dB)
(metal position tape)
Signal-to-Noise Ratio: 60dB (metal position tape,
Dolby NR out)
A noise reduction of 10dB above
SkHz and SdB at 1kHz is possible
with Dolby B NRI A noise reduction
of 20dB at SkHz is possible with
Dolby C NR.
Input Jacks: Mic jacks: 2
Input sensitivity: 0.6mV/600
ohms
Input impedance: 2.7 kohms
Line IN: 2
Input sensitivity: 60mV
Input impedance: 50 kohms

F Outputs: Line OUT: 2
1 ® Std output level: SOOmV (OdB)
I Optimum load impedance: over
50 kohms
Headphone Jack: 1

MAKE LEAKAGE-CURRENT OR RESISTANCE
MEASUREMENTS TO DETERMINE THAT EX-
POSED PARTS ARE ACCEPTABLY INSULATED
FROM THE SUPPLY CIRCUIT BEFORE RETURN-
ING THE APPLIANCE TO THE CUSTOMER.

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TA-2048

Optimum load impedance: 8-200

ohms
Motors: DC servo motor: 1
DC motor: 2
Heads: REC/PB heads: Special Hard
Permalloy

Erase head: Ferrite
Power Supply: AC l2OV/6O Hz
Power Consumption: 28 watts

Dimensions: 435 (W) x 112 (H) x 360 (D) mm
07-1/8 x 4-3/8 x 14-1/8)
Weight: 5.8 kg. (12.8 lbs.)

Specifications and external appearance are subject to
change without notice because of product improvements:

SERVICE PROCEDURES

1. Replacing the lamp
This unit used the lamp listed below.

Circuit No. Parts No. Description
PL-901 210090 ISOmA, 14V, Lamp
PL-902 210183 600mA, 14V, Lamp

Caution; Before replacing the lamp. Be sure to unplug the
power supply cable.

2. Instruction resistance measurement

Connect the insulating-resistance tester between the plug of

power supply cord and chassis.

Specifications; 500V more than lOMn

3. Replacing the Hall le
Cautions: As the position of leg of DN6838 and DN838
differ, use the same Hall [C when replacing.

(DNGEJB (222558) DNBBG (222470)

9'" Printed side

1

5mm t
snvraozsr 3"
Holder &
snansor 7:

FEATURSE

Three Heads with Special Hard Permalloy

For Superior Metal Tape Performance

Having three heads means you can monitor the actual re-
corded signal as you record instead of rewinding the tape to
check your recording afterward. The 3-head system also has
the advantage of making possible the use of separate record
and playback gaps, each optimized for its own task. The
special hard permalloy head formulation boasts the high
saturation flux density and abrasion resistance needed for
true metal tape compatibility.

ACCUBIAS For The Best Performance With Any Tape
The ACCUBIAS system fine tunes the recording bias to oh-

_2_

tain optimum performance with any kind of tape (except
metal tape). By setting precisely the correct bias level,
ACCUBIAS guarantees the flattest frequency response and
highest signal-to-noise ratio possible with each tape.

2-Motor Tape Transport with Separate Head Assembly
Motor

The tape transport system, along with the heads, deter-
mines the level of performance of a cassette deck. To assure
extremely stable and accurate transport, this unit uses a DC
servo-controlled capstan motor. This motor is unaffected
by fluctuations in the power supply voltage and frequency
and instantaneous changes in load. A highly reliable simple
drive transmission system and precision vertical cassette
holder further enhance overall accuracy and stability.
As a result, wow and flutter is under 0.045%. In addition,
separate DC motors drive the reel tables and head base and
the head assembly is constructed to move silently with no
annoying clicks.

Dolby B and C Noise Reduction

Along with standard Dolby B NR, this unit also has the
even more effective Dolby C NR system. Dolby C NR re-
duces tape background noise by 20dB at SkHZ, about 3
times more than Dolby B NR. In addition to its wide band
noise reduction, Dolby C NR uses a sliding band technique
that varies the band width of noise reduction according to
the input level. thereby avoiding noise pumping." Dolby C
NR also has an anti-saturation effect to reduce the chance
of tape saturation in the high range. All these features com-
bine to eliminate the adverse effects on.tape sound that
other noise reduction systems can cause.

Auto Music Control System (AMCS)

The AMCS automatically locates the beginning of every
song on a cassette in either the forward or the reverse
direction. M190 AMCS FWD is pressed during the play
mode, tape is rapidly wound to the beginning of the next
song and approximately the first 10 seconds is played. Then
the tape is rapidly wound forward to the beginning of the
next song and about 10 seconds is played. This process con~
tinues until the PLAY key is pressed to cancel AMCS ope-
ration and return to normal playback. When AMCS REV is
pressed during the play mode, the same process is per-
formed in the reverse direction.

Remote Control Unit Terminal

With an optional remote control unit (such as the RC-S T),
this unit can be controlled even while you are relaxing in
your favorite chair. All transport modes are included:
record, play, fast forward, rewind, stop and pause.

Auto Space Rec Mute Key
This key lets you insert unrecorded sections five seconds
long with just one quick tap.

Fully Automatic Tape Selection
This deck senses the type of cassette inserted and auto-
matically sets the correct amount of bias and equalization.