Akai AM-2600 Troubleshooting guide

RTV servis Horvat
| Kesinci, 31402 Semeljci ;
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AKAI STEREO INTEGRATED AMPLIFIER
MODEL AM-2600
SECTION 1 SERVICE MANUAL ...
SECTION 2 PARTS LIST .
SECTION 3 SCHEMATIC DIAGRAM
1
15
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SECTION 1
SERVICE MANUAL
TABLE OF CONTENTS
I. TECHNICAL DATA .2
II. DISMANTLING OF UNIT .3
III. CONTROLS .4
IV. PRINCIPAL PARTS LOCATION .5
V. LEVEL DIAGRAM .6
VI. MAIN AMPLIFIER ADJUSTMENT .7
1. IDLING CURRENT ADJUSTMENT ...7
2. LEVEL METER ADJUSTMENT .7
VII. CLASSIFICATION OF VARIOUS P.C BOARDS.8
1. RELATION OF P.C BOARD TITLE AND IDENTIFICATION NUMBER .8
2. COMPOSITION OF VARIOUS P.C BOARDS.9
For basic adjustments, measuring methods, and operating principles, refer to GENERAL OPERATING
PRINCIPLES AND ADJUSTMENTS.

I . TECHNICAL DATA
POWER AMPLIFIER SECTION
CONTINUOUS POWER OUTPUT
2-CHANNELS DRIVEN
60 watts per channel, minimum RMS, at 8 ohms from 20 to 20,000 Hz
with no more than 0.1% total harmonic distortion.
POWER BANDWIDTH (IHF)
7 Hz to 40 kHz/8 ohms (Total Harmonic Distortion: 0.1%)
SIGNAL TO NOISE RATIO (IHF)
PHONO
AUX
Better than 75 dB
Better than 95 dB
RESIDUAL NOISE
Less than 0.5 mV at 8 ohms
CHANNEL SEPARATION (IHF)
PHONO
Better than 55 dB at 1,000 Hz
DAMPING FACTOR
More than 60 (1 kHz, 8 ohms)
OUTPUT SPEAKERS
HEADPHONE
POWER INDICATOR METERS
A, B ( 4 to 16 ohms)/A+B ( 8 to 16 ohms)
4 to 16 ohms
(2) 3/80W switchable
PREAMPLIFIER SECTION
INPUT SENSITIVITY/IMPEDANCE
PHONO
AUX
TUNER
TAPE MONITOR
Phono 2: 3 mV/33, 47 or 100 k ohms
Phono 1: 3 mV/50 k ohms
150 mV/100 k ohms
150 mV/100 k ohms
PIN: 150 mV/100 k ohms
DIN: 150 mV/100 k ohms
OUTPUT LEVEL/IMPEDANCE
TAPE REC
PIN: 150 mV/100 k ohms
DIN: 30 mV/180 k ohms
FREQUENCY RESPONSE
PHONO (RIAA EQUALIZATION)
TUNER, AUX, TAPE MONITOR
30 Hz to 15 kHz +0.8 dB, -0.8 dB
7 Hz to 70 kHz +0 dB, -1 dB
TONE CONTROL BASS
TREBLE
±9 dB at 100 Hz
±9 dB at 10 kHz
LOUDNESS CONTROL
+10 dB at 100 Hz, +6 dB at 10 kHz (High Position)
+10 dB at 100 Hz (Low Position)
(Volume Control set at —30 dB position)
FILTER HIGH
LOW
—5 dB at 7 kHz (7 kHz position)
—3 dB at 10 kHz (10 kHz position)
—2 dB at 50 Hz (30 Hz position)
—6 dB at 50 Hz (60 Hz position)
MISCELLANEOUS
SEMICONDUCTORS Transistors: 35 Diodes: 17
POWER REQUIREMENTS
CSA, UL and LA models: 120V, 60 Hz
CEE models: 220V, 50 Hz
Other models: 110/220/240V, 50/60 Hz switchable
DIMENSIONS
440(W) x 141(H) x 331(D)mm, (17.3 x 5.6 x 13 inches)
WEIGHT 10 kg (22 lbs)
* For improvement purposes, specifications and design are subject to change without notice.

DISMANTLING OF UNIT
BOTTOM PLATE
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3

III. CONTROLS
Fig. 1 Controls
1. SPEAKER SYSTEM SELECTOR
2. OUTPUT POWER LEVEL METERS
(Left and Right)
3. METER SWITCH
4. MODE SWITCH
5. LOUDNESS SWITCH
6 VOLUME CONTROL
7. STEREO BALANCE CONTROL
8. INPUT SELECTOR
9. POWER SWITCH
10. HEADPHONE JACK
1 1 . AUDIO MUTE SWITCH
1 2. LOW FILTER SWITCH
1 3. HIGH FILTER SWITCH
14. TONE SWITCH
15. BASS TONE CONTROL
16. TREBLE TONE CONTROL
17. POWER INDICATOR LAMP
18. TAPE MONITOR SWITCH
#

IV. PRINCIPAL PARTS LOCATION
Fig. 3 Front View

LEVEL
IN
dB
V. LEVEL DIAGRAM

VI. MAIN AMPLIFIER ADJUSTMENT
1. IDLING CURRENT ADJUSTMENT
r . D a * Fig. 5 Main Amp. P.C Board M 2-5 43 2A
Connect a tester to Power Amp. P.C Board test point '
between Pin-11 and Pin-12, and between Pin-29 and
Pin-28.
Adjust semi-fixed resistors VR-la, VR-lb until the volt¬
age is 30 mV.
2. LEVEL METER ADJUSTMENT
Fig. 7 Volume P.C Board M2-5619
a) Connect instruments as shown in Fig. 6.
b) Turn volume control knob on the front panel until
the AC voltmeter indicates 4.9 volts (3 watts).
c) Adjust VR-3a,b so that level-meter indicates 3 watts.
(Refer to Fig. 7)
7

VII. CLASSIFICATION OF VARIOUS PC BOARDS
1. RELATION OF P C BOARD TITLE AND IDENTIFICATION NUMBER
P.C Board Title
- - ...]
P.C Board Number
Main Amplifier P.C Board
M2-5432
Tone Control P.C Board
M2-5618
Equalizer P.C Board
M2-5617
Volume P.C Board
M2-5619
Tape P.C Board
M2-5435
Chart—1
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