Onkyo A 7090 Service Manual

Page 1

SERIAL NO. 3063

ONKYO® SERVICE MANUAL

SUPER SERVO OPERATION
INTEGRATED STEREO AMPLIFIER
MODEL A-709O

a M urea:-

. q) @6696 (f) (D (D

TABLE OF CONTENTS

ITEM PAGE
Specifications _ 2
Precautions 2
Exploded View 3
Component location 4
Packing procedures 5
Circuit description 6
Schematic diagram 9
Preampli. pcb. View 1 1
Rectifier p.c.bi View 12
Main amplir pic.b. View 13
Main ampli adjustment I4
Equalizer ampIi. p,c,b. view 15

ON KYO®
Alllllfl BIIMPIIIIIIIIS

Page 2

A-7090

SPECIFICATIONS

POWER AMPLIFIER SECTION

Power Output:

Total Harmonic
Distortion:

(Aux. Input)

IM Distortion:

(Aux. Input)

(70 Hz: 7 kHz =4:1)

Frequency Response:

Damping Factor:

Rated Input:

Input Impedance:

Load Impedance:

Power Indicator
Ranges:

1 10 watts per channel minimum
r.m.s. into 8 ohms, both channels
driven from 20 Hz to 20,000 Hz,
with no more than 0.018% total
harmonic distortion.

0.018% at rated power
0.016% at 1 watt output
0.018% at rated power
0.016% at 1 watt output

5 Hz ~80,000 Hz (:1 dB)
50 at 8 ohms

1.5 volts

50 kohms

4 ~ 16 ohms

X l, x0.l, x001

PRE-AMPLIFIER SECTION

Input Sensitivity &
Impedance:

Total Harmonic
Distortion:

IM Distortion (Aux):
(70Hz: 7kHz = 4: 1)

Frequency Response:

Phono Overload:
SignaHo-Noise Ratio:

PRECAUTIONS

Phono MC: 250uV, 40 ohms
Phone] & 2: 2.5 mV, 50 kohms
Tuner: [50 mV, 50 kohms
Aux: 150 mV, 50 kohms
Tape Play 1 & 2: 150 mV,

50 kohms

0.01% at rated output
0.01% at rated output

Phono: 20Hz~20,000Hz 10.2 dB

Aux: IOHZ~50,000H2 +0,71 dB
250 mV r.m.s. at (112, 0.018% THD
Phono MC: 68 dB (IHF A weighted)
Phono MM: 78 dB (IHF A weighted)
Aux: 90 dB (lHF A weighted)

Output Voltage:
Output impedance:

Tone Controls:

Turnover Frequencies:
Filters:
Muting:

Loudness:

GENERAL
Outputs:

Inputs:

AC Outlets:
(only 120V model)
Semiconductors:

Power Supply:
Dimensions (WxHxD):

Weight:

Pre out: 1.5 volts

Rec out: 150 mV

Pre out: 1.8 kohms

Rec out: 3.3 kohms (PHONO)

Bass: ilO dB at 100 HZ
(turnover at 400 Hz)

Treble: :10 dB at 10 kHz
(turnover at 2 kHz)

Bass: 400 HZ, 125 HZ

Treble: 2 kHz, 8 kHz

High: 6 kHz (12 dB/oct)

Subsonic: 15 Hz (12 dB/oct)

720 dB

+5 :18 at 100 Hz
+5 dB at 10 kHz

Speakers A, B & C, Headphones,
Tape Rec 1,2

EPS out

Phono l, 2 & MC

Tuner

Aux

Tape Play 1 & 2

EPS in

2 switched 200 watt max.

1 unswitched 100 watt max.

8 FETs, 74 transistors, 41 diodes,
6 [CS

AC 120V, 60 Hz or AC 220V, 50 Hz
418 mm x155 mm x 410 mm
16-1/2" x 6-1/8"x16-3/16

18 kg, 396 lbs.

Specifications and features are subject to change without

notice.

1. For continued protection against fire hazard, replace only with same type and same rating fuse.
PARTS NO.

AC fuse

5A (ST-6)
3A-T

252050 (110/120V model)
252003 (220/24OV model)

2. Replacement for power amplifier transistors, if necessary, must be made from the same beta (hFE) group as the original

type.

3. Always disconnect the chassis from power line wheen soldering.
Turning the power switch OFF is not enough.
Power line leakage passing through the heating element may destroy the transistors.