Reference 7270 series II Seven Channel Amplifier OWNER'S MANUAL B & K Components Ltd. P/N 13009 Rev.0102 B&K Components, Ltd 2100 Old Union Road Buffalo, New York 14227 P/N 13009 Rev.0102 TABLE OF CONTENTS Safety Precautions Purpose and function Design and construction Features Rear panel view Rear panel description Level controls Inputs Outputs System installation Making the connection Control Muting Troubleshooting Care and cleaning Specifications Warranty Accessories included: Manual and Power cord page 2 page 3 page 3 page 3 page 4 page 4 page 5 page 5 - 6 page 6 page 7 page 8 page 9 page 10 page 10 page 11 page 12 Page 1 P/N 13009 Rev.0102 SAFETY PRECAUTIONS PLEASE READ BEFORE INSTALLING WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. The lightning flash with an arrowhead, within an equilateral triangle, is intended to alert the user of the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of a sufficient magnitude to constitute a risk of electric shock to you. The exclamation point within an equilateral triangle is intended to alert the user of the presence of important operating and maintenance (servicing) instructions in the literature accompanying the unit. y Observance of polarity is essential. Double-check connections before turning the amplifier on. The amplifier can be damaged if the unit is connected when its polarities are incorrect. Damage can occur to your speakers if the power rating* of each individual driver is exceeded by the amplifier. Make sure that all the drivers in your speaker system are capable of handling not only the continuous power being delivered by the amplifier, but the energy that is likely to be generated during strong and dynamic passages. Turn the amplifier `off' before plugging in or unplugging the input and speaker cables!!! The Reference 7270 series II is equipped with raised feet so that continuous ventilation can be maintained. They also help to keep acoustic feedback into the amplifier at a minimum. Additionally they provide a measure of protection against scratching any surface the unit might be resting on. Do not alter or remove them. Do not stack anything on top of the amplifier (preamplifier, processor, source, etc.). Leave at least 2-3 inches clearance from the top of the amplifier to the next shelf, component, etc., to insure proper ventilation. * If you are at all unsure of what the speaker `ratings' are, contact your dealer. y y y y y Page 2 P/N 13009 Rev.0102 THE REFERENCE 7270 SERIES II PURPOSE AND FUNCTION The Reference 7270 series II is a high current, seven channel power amplifier. It is designed to be used in all types of audio or audio/video systems. DESIGN AND CONSTRUCTION The Reference 7270 series II utilizes high quality electronic circuitry to achieve an environment wherein a detailed, transparent, and highly musical sound can be realized. The high quality parts complement includes; state-of-the-art solid state devices, 1% metal film resistors, computer grade electrolytic power supply capacitors, and a high capacity toroidal transformer. The Reference 7270 series II operates with a class A predriver and AB high current MOSFET power output stages. It is capable of reproducing the most demanding audio signals at its rated power levels. FEATURES THX Ultra Certified - The unit has passed a rigorous series of Lucasfilm THX quality and performance tests and it is guaranteed that this amplifier will give superb performance for years to come. Toroidal Transformer - Efficient, high current, shielded transformer that supplies the amplifer with a clean and constant supply of power, even during highly demanding source material passages. Discrete Circuitry - Dynamically provides a full, accurate, and three dimensional reproduction of source material. Class A Predriver - Improves low level detail and clarity for smoother, more musical sound. AB MOSFET Output Stage - Provides efficient and linear power delivery, as well as protection from thermal overload. Gold Plated Connectors - Improved connections for better sound quality and minimized signal loss and degradation. 1% Metal Film Resistors - Higher quality resistors for lower noise, better sound, and a greater degree of repeatability. High Current - Ability to cleanly, accurately, and reliably reproduce demanding recordings or source materials into low impedance drivers and speaker systems. Computer Grade Capacitors - Large capacity computer grade electrolytic capacitors for extended low frequency control, increased power supply, and improved dynamics. Fused Outputs - Provides limited protection from accidental shorting of amplifier outputs. Heavy Duty Gold Binding Posts - Improved current carrying capacity and sound quality Page 3 P/N 13009 Rev.0102 Rear Panel View 4 2>=CA>; 8> 5 8= ?D C B ;4E4; 2>=CA>;B ;4E4 ; : ;4E4 ; ! ;4E4 ; " ;4E4 ; # ;4E4 ; $ ;4E4 ; % ;4E4 ; & ( 6,03/< 6281' %(77(5 ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 C5B >? 6 8=? DC 8=? DC ! 5DB 4 8=? DC " 8=? DC # 5DB 4 8=? DC $ 5DB 4 8=? DC % 8=? DC & 5DB 4 5DB 4 31ED9?>* ?6 69B5 #,*" 6?B 3 ? >D 9 > E5 4 B9C; "% F ?> G9D8 C 1 =5 1719>CD DI@5 B5 @ <1 3 5 7 270==4; >DC?DC 270==4; >DC?DC ! 270==4; >DC?DC " 270==4; >DC?DC # 270==4; >DC?DC $ 270==4; >DC?DC % 270==4; >DC?DC & ?;DB 1 F ? 5 20DC8>= 2 3 1. AC fuse holder 2. AC Input receptacle 3. Speaker outputs 4. Amplifier control muting input/output 5. Level controls 6. Inputs 7. Speaker fuses REAR PANEL DESCRIPTION 1. AC fuse holder - Holds the AC Line fuse. This fuse is a 15 Amp / 250 Volt Slow Blow fuse. Replace only with the same type and value fuse. 2. AC Input receptacle - For attaching the supplied AC power cord to the amplifier. 3. Speaker outputs - For connecting the speakers to the amplifier. Explained further on page 6. 4. Amplifier control muting input/output - To provide remote switching of the mute on/off feature of the amplifier. Explained further on pages (8 - 9). 5. Level controls - For adjusting the input level of each channel into the amplifier. There are seven level controls on the back of the amplifier. One level control for each channel. 6. Inputs - For connecting signal patch cables (interconnects) from the preamplifier to the amplifier to pass a signal. Pages (5 - 6). 7. Speaker Fuses - Protection against amplifier damage in the case of shorted speaker wires. Replace fuse with the same value 6 AMP T-Lag only! VERY IMPORTANT! Page 4 P/N 13009 Rev.0102 LEVEL CONTROLS /8& $ 6 ) , /0 # THX certified units are denoted by the THX Ultra logo on the faceplate of the unit. For use in THX reference theater system, the level controls must be set to the full clockwise position (highest possible level). Generally in a home theater application, the level controls on the rear will not be used. All of the levels will be matched through the surround processor. In a system that uses the Reference 7270 series II for other applications, adjustment of level controls may be needed. Start with the level controls turned all the way up (fully clockwise), then adjust the level according to your system requirements to match each speaker as to produce the same sound pressure level with the same reference input. When using a combination of different speakers that may have different speaker ratings and efficiencies, the level controls may be used to match the output level of the speakers in the system. Example: Using a speaker with an efficiency of 93 dB @ 1w/1m and a speaker with an effiency of 97 dB @ 1w/1m together. A 97dB speaker may sound louder than a 93 dB speaker at a given volume level. The level control for a 93 dB speaker would be set at a relative level that is higher than a 97 dB speaker to match their audio volume levels. Turning the level control knob clockwise will increase the relative output volume of the speaker. Turning the level control knob counter clockwise will decrease the relative output volume of the speaker. INPUTS RCA type connectors accept line inputs from the preamplifier's output connectors. There are seven input connectors, one for each channel, that may be used to connect the amplifier to the preamplifier. RCA cable connector Page 5 P/N 13009 Rev.0102 Here is a typical preamplifier to amplifier setup: 8 =? DC B ;4 E4 ; 2 > = C A> ; B ;4 E 4; ;4 E 4; ! ;4 E 4; " ;4 E 4; # ;4 E 4; $ ;4 E 4; % ;4 E 4; & ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 ;> 78 8= ?D C 8= ?D C ! 8= ?D C " 8= ?D C # 8= ?D C $ 8= ?D C % 8= ?D C & Five way binding posts are provided. There is one pair provided for each channel. They are designed to accept a banana-type plug, spade-lug connector (shown below), terminal posts, and bare wire, and they are color coded for easy identification. The positive (+) post should always be connected to the speakers (+) jack. The negative (-) post should always be connected to the speakers (-) jack. Here is a typical amplifier output setup: 27 0= =4 ; > DC ? D C ? ; DB SB L SR SB L SL From Rear Left O utput L From Front Left O utput C From Center Output R From Front Right O utput From Rear Right O utput Fro m Surr Back Right O utput Fro m Surr Back Left O utput < 8= D B OUTPUTS Spade connector Banana jack 27 0= =4 ; ! > DC ? D C 27 0= =4 ; " > DC ? D C 27 0= =4 ; # > DC ? D C 27 0= =4 ; $ > DC ? D C 27 0= =4 ; % > DC ? D C 27 0= =4 ; & > DC ? D C ? ; DB < 8= D B ? ; DB < 8= D B ? ; DB < 8= D B ? ; DB < 8= D B ? ; DB < 8= D B ? ; DB < 8= D B 20 DC8 >= Page 6 P/N 13009 Rev.0102 SYSTEM INSTALLATION There will most likely be a number of cables involved in the installation of your home entertainment system. Preplanning is essential in order to maximize system efficiency. We recommend the following as a means of helping you reach that goal: Make a diagram of your proposed system by laying out the relative location of each component in the system. Then lay out the proposed cable runs between them. Number each cable and record its length on the diagram for future reference. Cable runs are critical in that they must be kept away from sources of power radiation (amplifiers, power cords, heaters, appliances, etc). For safety reasons, they should also be kept out of traffic areas. The process of optimizing the system will include the type of cable, the length of the run, and the obstructions it must deal with along its run. Your dealer can advise you on the products available and their relative merits. If building custom length audio cables is not your strength, your dealer should be able to help you with that as well. When possible, use a separate AC power line for the amplifier, one that is not shared by any other household component. THIS IS VERY IMPORTANT!!! Tip: Take a piece of string (longer than the longest cable run) and mark it at each foot of length. Then do a mock cable run using the string, dressing it neatly along the way. Count the divisions to the next full foot, and add one foot to allow for some movement of the components. This will provide you with the ideal cable length. Page 7 P/N 13009 Rev.0102 MAKING THE CONNECTION Before doing anything, insure that the power switch on the amplifier's front panel is in the `off' position. Again, it is recommended that you locate a separate AC power outlet for the amplifier, one that is not shared by any other audio component in the system or any other household component. This will eliminate the possibility of the amplifier `modulating' the power being supplied to the component and compromising the signal originating from that component. Locate the AC power cord provided with the amplifier and plug it into the power input receptacle in the rear panel. Do not connect it to the AC power source yet! Connect the audio cables from your preamplifier's output to the corresponding input connector on the amplifier. Connect the wires from your speakers to the appropriate outputs on the amplifier. It is absolutely essential that you observe correct polarity in all of these connections. Example: If you connect your left front output of your preamplifier to channel 4 input on the amplifier, remember to connect your left front speaker wires to channel 4's outputs. Always observe polarity when connecting speakers, connect amplifiers (+) to the speakers (+) and amplifiers (-) to speakers (-). Double check all connections. Connect a playback unit (CD, DVD, VLD, Tuner, etc.) to the preamplifier. Turn on the preamplifier, turn the volume on the preamplifier to a minimum level, then turn on the amplifier (in that order). Set the source on the preamplifier to the playback unit you've just connected. Turn the volume up slowly and listen for music from all channels. If ...