Rotel RMA 90 Service Manual

Page 1

Technical
Manual

TABLE OF CONTENTS
PART I: RMA-eo

STEREO MICRO
INTEGRATED AMPLIFIER

CASSETTE DECK

Serial No. Beginning
NE31811

RMA-9O
RMD-QO

TABLE DES MATIERES
SECTION I: EMA-90

STEREO

Specifications ............................. 1 Caractéristiques ............................ 1

Alignment ............................... 2 Fiéglage .............................. 3

Addendum ............................... 2 Addendum ............................... 3

Parts List. . , .......................... .4 Liste des pieces ............................ 4

Chassis Layout (Top View) .................. .5 Installation du chassis (vue de dessus) ............... 5

P-c Board Diagrams .......................... 6 Diagrammes des plaquettes de circuits imprimés ......... 6

Schematic Diagram .......................... 7 Diagramme schematique ....................... 7

PART II: RMD«90 SECTION II: RMDBO

Specifications ............................. 9 Caractéristiques ............................ 9

Alignment .............................. 1O Alignement ............................. 12

Troubleshooting Guide ....................... 11 Guide de dépannage ........................ 13

Parts List .............................. 14 Liste des piéces ........................... 14

Disassembly Diagram ........................ 15 SChémfl d5 démontage ----------------------- 15

Chassis Layout (Top View) , , ________________ 17 Installation du chassis [vue de dessus) .............. 17

Block Diagram .......................... 17 Schéma svnoptique ................

Schematic Diagram ............... 18 Diagramme schematique .....

P4; Board Diagrams ............... 20 Diagrammes des plaquettes de circurts imprimes ........ 20
RM/ \ 90 STEREO MICRO INTEGRATED AMPLIFIER
SpeCIfIcatIons Caracteristiques
Continuous Power Output. . .30 watts" per channel, min. RMS Frequency ReSPDVSBi

both channels driven into 8 ohms PHONO ........... 30 to 20,000H2, t0.5dB (RIAA STD)

from 20 to 20,000H2 with no more

than 0.03% total harmonic
distortion.
.No more than 0.03% (continuous
rated power output)
No more than 0.02% (continuous
1/2 rated power output)
No more than 0.03% (1 watt per
channel power output, 8 ohms)
.No more than 0.03% (continuous
power output)
No more than 0.02% (continuous
1/2 rated power output)
No more than 0.03% (1 watt per
channel power output, 8 ohms)
Output: Speaker ........ 8 ohms

Headphone. . . . 4-16 ohms
Damping Factor ...... 30 (20 to 20,000Hz, 8 ohms)
Input Sensitivity/Impedance

Total Harmonic Distortion. .
(20w 20,000Hz. from AUX)

Intermodulation Distortion .
(60H2 : 7kHz = 4 : 1)

PHONO (MM) ..... 5mV/47 kohms

TUNER, AUX ..... 150mV/33 kohms

TAPE MONITOR ...... 150mV/33 kohms
Overload Level (T.H.D. 0.5%, 1kHz):

PHONO 1 .......... 130mV

TUNER, AUX, TAPE . . .5V

THE HOTEL CO" LTD.

HOTEL ELECTRONICS CO" LTD.
HOTEL OF AMERICA. INC.

HOTEL HI FI LIMITED.

TUNER, AUX, TAPE t . .5 to 70,000Hz, +,O.2dB, 71.0dB

Tone Control:

Loudness Contour . . .

BASS ............. tIOdB, IOOHZ

TFIEBLE ........... t10dB,10kHz
..+10dB(100Hz),+4dB(10kHz)

40dB position)

(volume control set at

Signal- to- N-oise Ratio (IHF, A network):

PHONO 1 .......... 75GB

TUNER. AUX ........ 95dB

TAPE MONITOR ...... 95dB
MISCELLANEOUS
Power Requirement ....... 120V/60Hz, 220V/50Hz,

240V/50H2, or 120, 220,
240V/50-60Hz lswitchable)

Power Consumption . . .275 watts

Dimensions (overall) ...... 279 (W) x 66 (H) x 262 (D) mm
11" x 2-19/32" x10-15/16

Weight (net) ........... 4.5kg/99 lbs.

0 Specifications and design subject to possible modification

without notice.

Measured pursuant to the Federal Trade Commissions
Trade Regulation Rule on Power Claims for Amplifiers
(applicable to the U.S.A. only).

1-36-8 OHOKAYAMA, MEGURO-KU, TOKYO 152, JAPAN

2ND FLOOR, EVERGLORV BLDG, Not 305, SECTION 3.
NANKING E. ROAD, TAIPEI, TAIWAN, REPUBLIC OF CHINA

13528 30. NORMANDIE, GARDENA, CALIFt 90249, U.StA,

2-4 ERICA ROAD, STACEY BUSHES, MILTON KEYNES,
BUCKINGHAMSHIHE, ENGLAND

Page 2

EITGLlS?Ll

Alignment

Instruments: Oscilloscope, DC millivoltmeter

POWER AMP SECTION

A. DC Balance Adjustment

1. Set vertical gain control of the oscilloscope to 0.1V/
cm, and vertical input switch to GND. Bring the trace
to central position on the screen; then set the vertical
input switch to DC position.

2. Connect the oscilloscope to pin 9 (8 for R-chl on
H-AF-117 p-c board. Set volume control of the
amplifier to minimum position. Turn on the power.
When DC output appears on the screen (the trace will
shift upwards or downwards as shown in Fig. 1),
adjust potentiometer VR601 (VR602 for R-ch) on
H-AF-117 p-c board so that the DC voltage present at
the test point is 0V:50mV.

OSCILLOSCOPE

, E F W

L'CH

VRGO]

VRSOZ

Fig. 1

B. Bias (Idling Current) Adjustment

1. Connect the plus lead of DC millivoltmeter to pin 5
(pin 6 for R-chl, on H»AF-117 p-c board and the
minus lead to TP (TP for Rich). Set volume control
to minimum position. Turn on the power.

2. Adjust potentiometer VR603 (VR604 for R-ch) on
H-AF-117 p-c board so that the DC millivoltmeter

reads 10mV.
DC MlLLlVOLTMETER

LIL
TP TP
60- 5
W-CH L-CH
vnsoz. vneos
L
G l 2'

Fig. 2

ADDENDUM

1. The following modifications have been made on the
tone control circuit:
Reason: To improve frequency response.

T0162 p-c board

L-ch R-ch
C301 0302 10mfd -> 22mfd
C303 C304 0.01 mfd --> 0.015mfd
C307 C308 0.1mfd -> 0.12mfd
R303 R304 33kohms -> 27kohms
R307 R308 680 ohms -> 560 ohms
R309 R310 3.3kohms ->2.7kohms
H-AF-117 p-c board
0607 0608 10mfd (LN)->33mfd (LN)

The above modifications are applicable to the units with
serial number beginning NE40001.