Quality Uncompromised

T echnical Manual

Table of Contents

Specification..1 Parts List..2 ~ 6 Adjustment..7 ~ 8 PCB Assembly..9 Schematic Diagram.10

STEREO POWER AMPLIFIER

RB-1090-3

Specification

Continuous Power Output (20-20kHz, < 0.03%) Total Harmonic Distortion(20-20kHz, 8 ohms) Intermodulation Distortion(60Hz : 7kHz, 4:1) Frequency Responce ( 1dB) Dampning Factor(20-20,000kHz, 8 ohms) Speaker Impedance(combined load) Signal to Noise Ratio(IHF A network) Input Impedance / Sensitivity Power Requirement Power Consumption
Dimensions(W x H x D) Panel Height Weight (net)
380 wats/ch into 8 ohms 700 wats/ch into 4 ohms < 0.03 % < 0.03 % 10 Hz - 100 KHz ohms minimum 125 dB 33 k ohms / 1.8 volt 115 volts 60 Hz or 230 volts 50 Hz 800 watts
432 x 237 x 406 mm 171/8 x 93/9 x 15 inches 221 mm 38 kg, 83.6 Lb.
BUNZAN-SHINSEN-BLD. 4F 10-10 SHINSEN-CHO, SHIBUYA-KU, TOKYO 150-0045, JAPAN

Serial. NO.

Begining 2311001

Y-316D-0209/pdf

Appearance

POWER AMPLIFIER RB1090

RB-1090

PROTECTION L R

RIGHT INPUT
BALANCED UNBALANCED BALANCED

LEFT INPUT

BALANCED UNBALANCED

UNBALANCED

POWER AMPLIFIER MODEL NO. RB-1090 POWER CONSUMPTION: 800W

CAUTION

RISK OF ELECTRIC SHOCK DO NOT OPEN AVIS: RISQUE DE CHOC ELECTRIQUENE PAS OUVRIR

RIGHT SPEAKER

LEFT SPEAKER
W ARNING: TO REDUCE THE RISK OF FIRE
OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.

Parts List 1/3

SYMBOL PARTS NO. 016 X-1271D01-08 PCB ASSY
L601-602 IC701,702 IC501,502 Q621,622 Q619,620 Q613,614,667,668 Q902 Q615,616,669,670 Q901 Q607-612,657-662,747-750 Q751-754 Q601-606,651-656,745,746 Q755-758 D609-612,903,904 D601-608,615,616 D701,702,713,714 D751-754 D905,906 D902 C910,911 C611,612 C601,602 C607,608,505-508 C703,704 C707,708 C717,718 C701,702 C705,706 C903,904 C623-626 C709,710 C613-616 C627,628 C691,692 C501,502 C603,604 VR601-604 R1 R777,778 R607-610,615-618,908,909 R785,786 R715-730 R623,624,629,630 R687-690,697,698 R701,702,705,706 R505-508,711,712,(R905) R703,704 R621,622,643,644,733,734 R775,776 R509,510,631,632,731,732,R766 R691,692 R611,612,619,620,667-670 R501-504,699,700,707,708 R627,628 R773,774 R787,788 R633,634 R671-686,693-696,781-X-1271D 021 TRL-MPC1237HA 031 OPA134PA 032 ACA1209-ST 033 B631-EF 033 C2911-ST 033 D600-EF 033 TA1016-FG 033 TA1376A-LKU 033 TC2362-FG 033 TC3478A-LKU 034 T1N4003-TB 034 T1N4148-T1N4148-T1N4148-TRD16JSTW02M 041 25BGF470M 041 35ZA10MTZ 041 35ZA4R7MTZ 041 TEEUFC1E101SB 041 TUTES1E221-TF 041 TUTES1E470-TF 041 TUTES1H100-TF 041 TUTES1H220-TF 041 TUTES1H4R7-TF 041 TUTES1J221-TS 041 VX2A102S 042 TP50V223J 044 FSC160V221H 044 FSC160V471H 044 KT18-2E104J 044 S50V100PJ 044 TFKP2-2A681H 051 SFR001-ERQ2ABJP220S 054 TMFR401KTMFR401KTMFR401KTMFR4010R 054 TMFR4100R 054 TMFR4100K 054 TMFR4100K 054 TMFR4010K 054 TMFR4120K 054 TMFR4150K 054 TMFR4015K 054 TMFR4001K 054 TMFR4001M 054 TMFR4220R 054 TMFR4022K 054 TMFR403KTMFR4033K 054 TMFR404KTMFR4047R 054 TMFR4047K PCB ASSY SPEAKER COIL 1.6F 9T IC (PROTECTION) IC (OPEAMP) TRANSISTOR 2SA1932 TRANSISTOR 2SC5174 TRANSISTOR 2SA1209-ST TRANSISTOR 2SB631K-EF TRANSISTOR 2SC2911-ST TRANSISTOR 2SD600K-EF TRANSISTOR 2SA1016KAA-FG TRANSISTOR 2SA1376AT-LKU TRANSISTOR 2SC2362KAA-FG TRANSISTOR 2SC3478AT-LKU DIODE 1N4003-E DIODE 1N4148TAP-50 DIODE 1N4148TAP-50 DIODE 1N4148TAP-50 ZENER DIODE 16V (AB2) POWER DIODE 1.5A200V ELECTROLYTIC CAPACITOR 25V470uF ELECTROLYTIC CAPACITOR 35V10uF ELECTROLYTIC CAPACITOR 35V4.7uF ELECTROLYTIC CAPACITOR 25V100uF ELECTROLYTIC CAPACITOR 25V220uF ELECTROLYTIC CAPACITOR 25V47uF ELECTROLYTIC CAPACITOR 50V10uF ELECTROLYTIC CAPACITOR 50V22uF ELECTROLYTIC CAPACITOR 50V4.7uF ELECTROLYTIC CAPACITOR 63V220uF ELECTROLYTIC CAPACITOR 100V1000uF MYLAR CAPACITOR 0.022uF STYROL CAPACITOR 160V220pF STYROL CAPACITOR 160V470pF MP CAPACITOR MKT1818-410/254 STYROL CAPACITOR 50V100pF P.P CAPACITOR FKP2-100V681H SEMI-FIXED RESISTOR VM6CKPH1S-2.2K FUSE RESISTOR 2W 22 METAL FILM RESISTOR 1/4W 1.2K METAL FILM RESISTOR 1/4W 1.5K METAL FILM RESISTOR 1/4W 1.8K METAL FILM RESISTOR 1/4W 10 METAL FILM RESISTOR 1/4W 100 METAL FILM RESISTOR 1/4W 100K METAL FILM RESISTOR 1/4W 100K METAL FILM RESISTOR 1/4W 10K METAL FILM RESISTOR 1/4W 120K METAL FILM RESISTOR 1/4W 150K METAL FILM RESISTOR 1/4W 15K METAL FILM RESISTOR 1/4W 1K METAL FILM RESISTOR 1/4W 1M METAL FILM RESISTOR 1/4W 220 METAL FILM RESISTOR 1/4W 22K METAL FILM RESISTOR 1/4W 3.9K METAL FILM RESISTOR 1/4W 33K METAL FILM RESISTOR 1/4W 4.7K METAL FILM RESISTOR 1/4W 47 METAL FILM RESISTOR 1/4W 47K

RB-1090-2

DESCRIPTION

Parts List 2/3

SYMBOL
R771,772,779,780,613,614 R657,658 R713,714,625,626 (R905) R709,710 R663,664 R789,790 R655,656 R659-662 R763-765,767-770 R751-758 R759-762 R665,666 R635-642,645-652 R653,654 R601,602 R603,604 R613,R614 S901 RY601,602 S401 DJ1,DJ2 CON1,CON2 N1,N2,P1,P2,OUT1,OUT2

PARTS NO.

054 TMFR4560R 054 TMFR4056K 054 TMFR406KTMFR406KTMFR4068K 054 1WS10JF 054 1WS330JF 054 3WS10JF 054 3WS6.8KJF 054 MF16-1001-A 054 MF16-22R0-A 054 MF16-6801-A 054 TMFMPC74-0.22F 054 MPC71-1F 054 TRC55Z1501F 054 TRC55Z3302F 054 TRC55Z5600F 061 C-4176ADE2TU-C-4613AC-4575AC-3683#C-4446A00
METAL FILM RESISTOR 1/4W 560 METAL FILM RESISTOR 1/4W 56K METAL FILM RESISTOR 1/4W 6.8K METAL FILM RESISTOR 1/4W 6.8K METAL FILM RESISTOR 1/4W 68K METAL OXIDE FILM RESISTOR 1W 10 METAL OXIDE FILM RESISTOR 1W 330 METAL OXIDE FILM RESISTOR 3W 10 METAL OXIDE FILM RESISTOR 3W 6.8K MOF RESISTOR 1/6W 1K MOF RESISTOR 1/6W 22 MOF RESISTOR 1/6W 6.8K MOF RESISTOR 330 RESISTOR PLATE 5W 0.22 RESISTOR PLATE 5W 1 RESISTOR RC55Z 1.5K RESISTOR RC55Z 33K RESISTOR RC55Z 560 POWER SWITCH PS3-22-L3AV TV-8 (4P PCB) RELAY DE24D2-OT(M) TOGGLE SWITCH 200DP1T2B2M7RE 3P CANON JACK (FEMALE) YKF52-5006 PCB TERMINAL 3P P7.5 TP WE-12 I-753NA PCB TERMINAL Y-105
016 X-1291_01-02 PCB ASSY
T101 D101 F101 F903 C101 R106 K104 AC1.ACX-1291E 022 T-1075NW02M 036 5STR251-TUTES1E471-TS 054 1WS120JF 068 C-3681#C-4422A01 PCB ASSY SUB TRANSFORMER (with 016 X1291E) POWER DIODE 1.5A 200V FUSE 250VT500MA FUSE F250MA ELECTROLYTIC CAPACITOR 25V470uF MOF RESISTOR 1W 120 WRAPPING TERMINAL 2P WRAPPING TERMINAL 2P
016 E-1328A00 PCB ASSY (Surge Absorber)
TH902 D910 C920 R901 R901 RY901 TH901 TM1,TM4,TM5,TM6 TM2,TM3 ACN,ACL 501 E-1328A 034 SCK2RTIN4148-DE1307E472M 054 RWH20G10RJ 054 RWH20G5RJ 063 OZT-SS-112LMUI300B 068 C-3683#C-3683#C-4370A00 PCB ASSY SURGE CURRENT THERMISTOR 5 DIODE 1N4148TAP-50 SPARK KILLER 4700pF RESISTOR 20W 10 (for 230V VERSION) RESISTOR 20W 5 (for 115V VERSION) RELAY DC 12V TV8 OZT-SS-112LM1 THERMOSTAT UI-2 PCB TERMINAL 2P P7.5 TP WE-11 I-752NA WRAPPING PIN TERMINAL 4P PCB TERMINAL Y-102
016 X-1348A00 PCB ASSY (Delay)
T11 T12 D11 C11 R11,12,14 R13 KX-1348-A 032 TA608-FG 032 TC536-FG 034 TRD4.7JSTTUTES1H100-TF 053 CR14-103J-A 053 CR14-334J-A 068 C-3681#3 PCB ASSY TRANSISTOR 2SA608KAA-FG TRANSISTOR 2SC536KAA-F ZENER DIODE 4.7V (AB2) ELECTROLYTIC CAPACITOR 50V10uF CARBON RESISTOR 1/4W 10K CARBON RESISTOR 1/4W 330K WRAPPING TERMINAL 4P

HEAT SINKER ASSEMBLY

Q617,618 Q633,634 Q623-DA1294-OY 033 A1295-OY TRANSISTOR 2SD1953 TRANSISTOR 2SA1294-OY TRANSISTOR 2SA1295-OY

Parts List 3/3

Q635,636 Q637-644
033 C3263-OY 033 C3264-OY 019 TO-3P 019 TO-3P2
TRANSISTOR 2SC3263-OY TRANSISTOR 2SC3264-OY INSULATION SHEET(S) INSULATION SHEET(L)

OTHERS

011 FP-499A-B 011 FP-499A-S 011 SG4-02CRV4-09ARV4-09ASG4-05ASG4-05ASG3-18ARP-354C 019 C-4638AC-670#C-4418APK4-07A00T 022 T-1061UT-1064UBRLTL1214A 034 SEL1124R 034 SEL1E24W 036 5STALS30S1072MF 067 C-4717AC-4717AC-4637AC-4392AC-4393AC-4423AC-4639ASG3-22BSG3-23BSG4-24AZ-OMRB-1090-1 BLACK PANEL ASSY SILVER PANEL ASSY H/S PANEL PUSH BUTTON 14F (BLACK) PUSH BUTTON 14F (SILVER) SUB PANEL SUPPORT(BLACK). SUB PANEL SUPPORT(SILVER). UPPER COVER REAR CHASSIS CASTER 32 FELT 56 (for FOOT) PLASTIC FOOT 26 METAL FOOT 60 POWER TRANSFORMER POWER TRANSFORMER POWER SIODE 25A 400V LED (RED) 2 LED (RED) 1X5 LED (BLU) 1X5 FUSE 250V10A ELECTROLYTIC CAPACITOR 100V22000uF SPEAKER TERMINAL (BLACK) SPEAKER TERMINAL (RED)) AC INLET(3P) 0707-1-CW AC CORD SET (SJT AWG14) for USA AC CORD SET for EUROPE AC CORD SET for AUSTRALIA AC CORD SET for U.K. INSIDE CARTON -V01 SHIPPING CARTON -V01 PACKING (for INSIDE CARTON) STYROL MOULDING OWNER'S MANUAL(EFGISD)

T001 T002 D004,D005

C001-C008 SP2A,SP2B SP2A,SP2B
Addendum List for Black and Silver

RB1090

PARTS 011 FP-499A-B 011 FP-499A-S 011 SG4-02CRV4-09ARV4-09ASG4-05ASG4-05ASEL1124R 034 SEL1E24W
DESCRIPTION BLACK PANEL ASSY SILVER PANEL ASSY H/S PANEL H221 PUSH BUTTON 14F (BLK) PUSH BUTTON 14F (SLV) SUB PANEL CHASSIS (BLK) SUB PANEL CHASSIS (SLV) LED (RED) 1X5 LED (BLU) 1X5

Adjustment

Instruments : DC milli voltmeter Notes : Prior to Bias Adjustment, run about 5minutes with rated output(8ohms) and warm up Power Transistor and Heat Sink. Set input off.
Coupling L CH OUT R CH OUT TP1 TP2
Location X-1271-01 PCB X-1271-02 PCB X-1271-01 PCB X-1271-02 PCB
Adjust VR603 VR604 VR601 VR602
Adjust for DC milli voltmeter reads 0mV
DC milli voltmeter reads 5mV

2SA1016K 2SC2362K

2SB631K 2SD600K 2SA1209 2SC2911 2SD1953

2SA1294 2SC3263

C E 1 2

Owners Manual Manuel dutilisation Bedienungsanleitung Manuale di istruzioni Manual de instrucciones Gebruiksaanwijzing

RB-1090

Stereo Power Amplifier Amplificateur de Puissance Stro Stereo-Endstufe Finale di Potenza Stereo Etapa de Potencia Estereofnica Stereo Eindversterker

POWER AMPLIFIER RB1090

PROTECTION L R
1: Controls and Connections / Commandes et branchements / Bedienelemente und Anschlsse Controlli e collegamenti / Controles y Conexiones / De bedieningsorganen en aansluitingen

RIGHT INPUT

BALANCED UNBALANCED BALANCED

LEFT INPUT

BALANCED UNBALANCED

UNBALANCED

POWER AMPLIFIER MODEL NO. RB-1090 POWER CONSUMPTION: 800W

CAUTION

RISK OF ELECTRIC SHOCK DO NOT OPEN AVIS: RISQUE DE CHOC ELECTRIQUENE PAS OUVRIR

RIGHT SPEAKER

LEFT SPEAKER
WARNING:TO REDUCE THE RISK OF FIRE
OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
2: RCA Inputs & Dual Speakers / Entres Cinch-RCA et sorties enceintes doubles Anschludiagramm (Cinch-Eingnge und zwei Lautsprecherpaare) Ingressi RCA e Seconda coppia di diffusori Entradas RCA y Conexin de dos parejas de Cajas Acsticas De cinch- en luidsprekerverbindingen
PREAMPLIFIER / PRAMPLIFICATEUR / VORVERSTRKER / PREAMPLIFICATORI / PREAMPLIFICADOR / VOORVERSTERKER

BALANCED OUTPUTS

RCA OUTPUTS
3: Balanced Inputs & Bi-wire Speakers Entres symtriques et bi-cblage des enceintes acoustiques Anschludiagramm (Symmetrische Eingnge und Bi-Wiring) Ingressi bilanciati e Diffusori con bi-wire Entradas Balanceadas y Conexin de Cajas Acsticas en Bicableado De gebalanceerde ingangen en dubbele luidsprekerbedrading

English

WARNING: There are no user serviceable parts inside. Refer all servicing to qualified service personnel. WARNING: To reduce the risk of fire or electric shock, do not expose the unit to moisture or water. Do not allow foreign objects to get into the enclosure. If the unit is exposed to moisture, or a foreign object gets into the enclosure, immediately disconnect the power cord from the wall. Take the unit to a qualified service person for inspection and necessary repairs. Read all the instructions before connecting or operating the component. Keep this manual so you can refer to these safety instructions. Heed all warnings and safety information in these instructions and on the product itself. Follow all operating instructions. Clean the enclosure only with a dry cloth or a vacuum cleaner. You must allow 10 cm or 4 inches of unobstructed clearance around the unit. Do not place the unit on a bed, sofa, rug, or similar surface that could block the ventilation slots. If the component is placed in a bookcase or cabinet, there must be ventilation of the cabinet to allow proper cooling. Keep the component away from radiators, heat registers, stoves, or any other appliance that produces heat. The unit must be connected to a power supply only of the type and voltage specified on the rear panel of the unit. Connect the component to the power outlet only with the supplied power supply cable or an exact equivalent. Do not modify the supplied cable in any way. Do not attempt to defeat grounding and/or polarization provisions. Do not use extension cords. Do not route the power cord where it will be crushed, pinched, bent at severe angles, exposed to heat, or damaged in any way. Pay particular attention to the power cord at the plug and where it exits the back of the unit. The power cord should be unplugged from the wall outlet if the unit is to be left unused for a long period of time. Immediately stop using the component and have it inspected and/or serviced by a qualified service agency if: The power supply cord or plug has been damaged. Objects have fallen or liquid has been spilled into the unit. The unit has been exposed to rain. The unit shows signs of improper operation The unit has been dropped or damaged in any way Place the unit on a fixed, level surface strong enough to support its weight. Do not place it on a moveable cart that could tip over.
RB-1090 Stereo Power Amplifier

Contents

About Rotel.. 6 Getting Started.. 6 A Few Precautions Placement 6 7

About Rotel

A family whose passionate interest in music led them to manufacture high fidelity components of uncompromising quality founded Rotel over 30 years ago. Over the years that passion has remained undiminished and the goal of providing exceptional value for audiophiles and music lovers regardless of their budget, is shared by all Rotel employees. The engineers work as a close team, listening to, and fine tuning each new product until it reaches their exacting musical standards. They are free to choose components from around the world in order to make that product the best they can. You are likely to find capacitors from the United Kingdom and Germany, semi-conductors from Japan or the United States, and toroidal power transformers manufactured in Rotels own factory. Rotels reputation for excellence has been earned through hundreds of good reviews and awards from the most respected reviewers in the industry, who listen to music every day. Their comments keep the company true to its goal the pursuit of equipment that is musical, reliable and affordable. All of us at Rotel thank you for buying this product and hope it will bring you many hours of enjoyment.

Getting Started

Thank you for purchasing the Rotel RB-1090 Stereo Power Amplifier. When used in a highquality music or home theater system, your Rotel amplifier will provide years of musical enjoyment. There is nothing understated about the RB-1090. It is a massive two-channel power amplifier, capable of providing extremely high power output in the most demanding applications. In fact, the limiting factor in the RB-1090s output levels will often be the capacity of your homes electrical supply. Discrete output devices, a massive power supply with dual toroidal transformers, premium components, and Rotels Balanced Design ensure superb sound quality. High current capability allows the RB-1090 to drive difficult speaker loads with ease, including 2 ohm speakers. Be aware that the RB-1090 is capable of high power levels, in excess of 400 watts per channel into 8 ohms and 700 watts into 4 ohms. Make sure that your speakers can handle the power of the RB-1090. If in doubt about your speakers, ask your authorized Rotel dealer for advice. The RB-1090 is straightforward in its installation and operation. If you have experience with other stereo power amplifiers, you shouldnt find anything perplexing. Plug in a pair of high-quality RCA cables from your preamp into the amplifier inputs, wire up your speakers, and enjoy. Alternatively, the RB-1090 provides an optional pair of balanced inputs for use with preamps or processors that offer these lownoise XLR-connections. If you choose this option, you will need to reset a back panel switch selecting the balanced inputs. Again, nothing very confusing.
About THX Ultra.. 7 AC Power and Control.. 7 AC Power Input Power Switch Power Indicator Protection Circuitry 7
Input Signal Connections.. 8 Input Selector Switch RCA Inputs (unbalanced) XLR Inputs (balanced) 8
Speakers.. 8 Speaker Selection Speaker Wire Selection Polarity and Phasing Connecting the Speakers 8 8
Troubleshooting.. 9 Front Panel Power Indicator Is Not Lit No Sound Protection Indicator Is Lit 9

Specifications... 9

A Few Precautions
Please read this manual carefully. In addition to basic installation and operating instructions, it provides valuable information on various RB-1090 system configurations as well as general information that will help you get optimum performance from your system. Please contact your authorized Rotel dealer for answers to any questions you might have. In addition, all of us at Rotel welcome your questions and comments.

English Power Switch Power Indicator
The power switch is located in the center of the front panel of your amplifier. To turn the amplifier on, push the switch in. The LED indicator above the switch will light, indicating that the amplifier is turned on. To turn the amplifier off, push the button again and return it to the out position.
Save the RB-1090 shipping carton and all enclosed packing material for future use. Shipping or moving the RB-1090 in anything other than the original packing material may result in severe damage to your amplifier. Be sure to keep the original sales receipt. It is your best record of the date of purchase, which you will need in the event warranty service is ever required.
Before any home theater component can be THX Ultra certified, it must incorporate the THX technologies and also pass a rigorous series of quality and performance tests. Only then can a product feature the THX Ultra logo, which is your guarantee that the Home Theater products you purchase will give you superb performance for many years to come.

Placement

The RB-1090 generates heat as part of its normal operation. The heat sinks and ventilation openings in the amplifier are designed to dissipate this heat. The ventilation slots in the top cover must be open. There should be 10 cm (4 inches) of clearance around the chassis, and reasonable airflow through the installation location, to prevent the amplifier from overheating. Likewise, remember the weight of the amplifier when you select an installation location. Make sure that the shelf or cabinet can support its considerable bulk. Again, use common sense.

AC Power and Control

AC Power Input
Because of its high power rating, the RB-1090 can draw considerable current and may tax your homes electrical circuit. Therefore, it should be plugged directly into a 3-pin polarized wall outlet. Do not use an extension cord. A heavy duty multi-tap power outlet strip may be used, but only if it (and the wall outlet) is rated to handle the current demanded by the RB-1090.

Protection Circuitry

The RB-1090 features a thermal protection circuit that protects the amplifier against potential damage in the event of extreme or faulty operating conditions. Unlike many designs, the RB-1090s protection circuit is independent of the audio signal and has no impact on sonic performance. Instead, the protection circuit monitors the temperature of the output devices and shuts down the amplifier if temperatures exceed safe limits. In addition, the RB-1090 includes overcurrent protection which operates only when load impedances drop below 2 ohms. This protection is independent for the left and right channels with separate front panel PROTECTION LEDS for each. Most likely, you will never see this protection circuitry in action. However, should a faulty condition arise, the amplifier will stop playing and the PROTECTION LEDS on the front panel will light. If this happens, turn the amplifier off, let it cool down for several minutes, and attempt to identify and correct the problem. When you turn the amplifier back on, the protection circuit will automatically reset and the PROTECTION LEDs should go out. In most cases, the protection circuitry activates because of a fault condition such as shorted speaker wires, or inadequate ventilation leading to an overheating condition. In very rare cases, highly reactive or extremely low impedance speaker loads could cause the protection circuit to engage.

The RB-1090 has a built-in surge attenuator to prevent opening the electrical circuits breaker or fuse at turn-on.
Be sure the POWER SWITCH on the front panel of the RB-1090 is turned off (in the out position). Then, connect the supplied power cord to the POWER CONNECTOR on the back panel of the amplifier and to the AC power outlet. Your RB-1090 is configured at the factory for the proper AC line voltage in the country where you purchased it (either 115 volts AC or 230 volts AC with a line frequency of either 50 Hz or 60 Hz). The AC line configuration is noted on a label on the back panel.
The RB-1090 has caster wheels at the rear to help position it.

About THX Ultra

THX is an exclusive set of standards and technologies established by the world-renowned film production company, Lucasfilms Ltd. THX grew from George Lucas personal desire to make your experience of the film soundtrack, in both movie theaters and in your home theater, as faithful as possible to what the director intended. Movie sound tracks are mixed in special movie theaters called dubbing stages and are designed to be played back in movie theaters with similar equipment and conditions. The soundtrack created for movie theaters is then transferred directly onto Laserdisc, VHS tape, DVD, etc., and is not changed for playback in a small home theater environment. THX engineers developed patented technologies to accurately translate the sound from the movie theater environment into the home, correcting the tonal and spatial errors that occur.
Should you move your RB-1090 to another country, it is possible to configure your amplifier for use on a different line voltage. Do not attempt to perform this conversion yourself. Opening the enclosure of the RB-1090 exposes you to dangerous voltages. Consult a qualified technician or the Rotel factory service department for information.
If you are going to be away from home for an extended period of time such as a monthlong vacation, it is a sensible precaution to unplug your amplifier while you are away.

Input Signal Connections

The RB-1090 gives you a choice of two different kinds of input connections conventional unbalanced RCA type connections (such as found on nearly all audio equipment) or balanced XLR-type connections for use with some high-end preamps or digital processors featuring this lower noise connection.
Connect the other cable to the right channel BALANCED INPUT. Make sure that the INPUT SELECTOR SWITCH is in the balanced position.

Speakers

The RB-1090 has two sets of SPEAKER CONNECTORS for each channel. These can be used to connect two pairs of loudspeakers, or to connect one pair of loudspeakers with biwire connections.

one conductor. The wire may have clear insulation with different color conductors (copper and silver). There may be polarity indications printed on the insulation. Identify the positive and negative conductors and be consistent with every speaker and amplifier connection.

Connecting the Speakers

See Figure 2
The RB-1090 has two pairs of color coded binding posts per channel. These can be used to connect two pairs of loudspeakers by connecting one pair to the first speaker and the second pair to the other speaker. Alternatively, they may be used for bi-wire connections by connecting one pair to the high-frequency input on the speaker and the other pair to the low-frequency speaker input. These SPEAKER CONNECTORS accept bare wire, connector lugs, or dual banana type connectors (except in the European Community countries where their use is not permitted). Route the wire from the RB-1090 to the speakers. Give yourself enough slack so you can move the components enough to allow access to the SPEAKER CONNECTORS. If you are using dual banana plugs, connect them to the wires and then plug into the backs of the SPEAKER CONNECTORS. The collars of the SPEAKER CONNECTORS should be screwed in all the way (clockwise). If you are using terminal lugs, connect them to the wires. If you are attaching bare wires directly to the SPEAKER CONNECTORS, separate the wire conductors and strip back the insulation from the end of each conductor. Be careful not to cut into the wire strands. Unscrew (turn counterclockwise) the SPEAKER CONNECTOR collars. Place the connector lug around the shaft, or insert the bundled wire into the hole in the shaft. Turn the collars clockwise to clamp the connector lug or wire firmly in place.
NOTE: Be sure there are no loose wire strands that could touch adjacent wires or connectors.

Input Selector Switch

A toggle switch in the middle of the RB-1090s rear panel selects which type of input signal to use. The operation of this switch is self-evident. Put the switch in the unbalanced position when you are using the RCA-type inputs. Put the switch in the balanced position when using XLR-type connections.

Speaker Selection

The nominal impedance of the loudspeaker(s) connected to the RB-1090 should be at least 4 ohms. When driving multiple pairs of speakers in parallel configuration, the effective impedance the amplifier sees is cut in half. For example, when driving two pair of 8 ohm speakers, the amplifier sees a 4 ohm load. When driving multiple speakers in parallel, select speakers with a nominal impedance of 8 ohms or higher. Speaker impedance ratings are less than precise. In practice, very few loudspeakers will present any problems for the RB-1090. See your authorized Rotel dealer if you have any questions.

To prevent loud potentially damaging noises, make sure the amplifier is turned off when you make any signal connections.

RCA Inputs (unbalanced)

When a component with RCA connectors such as a preamplifier or surround sound processor supplies signals to the RB-1090, the RCA-type phono plug inputs should be used. Select high quality audio interconnect cables. Connect the left channel output of your preamp to the left channel UNBALANCED INPUT on the RB-1090. Connect the other cable to the right channel UNBALANCED INPUT. Make sure that the input selector switch is in the UNBALANCED position.

Speaker Wire Selection

Use insulated two-conductor stranded wire to connect the RB-1090 to the speakers. The size and quality of the wire can have an audible effect on the performance of the system. Standard speaker wire will work, but can result in lower output or diminished bass response, particularly over longer distances. In general, heavier wire will improve the sound. For best performance, you may want to consider special high-quality speaker cables. Your authorized Rotel dealer can help in the selection of appropriate cables for your system.

XLR Inputs (balanced)

See Figure 3
If you are using one of the high-end preamplifiers or processors with low-noise balanced signal outputs to drive your RB-1090, you may choose to use these low-noise XLR-type connections. See your authorized Rotel dealer for the appropriate cables. Connect the left channel output of your preamp to the left channel BALANCED INPUT on the RB-1090. When properly seated, the connector should click into the connection.

Polarity and Phasing

The polarity the positive/negative orientation of the connections for every speaker and amplifier connection must be consistent so all the speakers will be in phase. If the polarity of one connection is mistakenly reversed, bass output will be very weak and stereo imaging degraded. All wire is marked so you can identify the two conductors. There may be ribs or a stripe on the insulation of