B&K ST1200 Series User's Manual
Contents
1. ST 1200 series II Two Channel Amplifier OWNER S MANUAL B amp K Components Ltd B amp K Components Ltd 2100 Old Union Road Buffalo New York 14227 Table of contents Safety Precautions Purpose and function Design and construction Features Rear panel view Rear panel description Control muting Level controls Inputs Outputs Internal Bus Jumper description Mono application Bridged application System installation Making the connection Troubleshooting Care and cleaning Specifications Warranty Accessories included Manual and Power cord Page 1 Page 2 Page 3 Page 3 Page 4 Page 4 Page 5 Page 5 6 Page 6 Page 7 Page 8 Page 9 Page 9 10 Page 11 Page 12 Page 13 Page 13 14 Page 15 Page 15 Page 16 Page 17 CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN 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 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 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 Observance of polarity is essent2. Tighten repair or replace cable Check all switch settings correctly selected Check connections making sure that cables are connected to and to Speakers connected out of phase Sound lacks direction bass weak Loud hum or buzz on one 1 or more channels Low output from amplifier Check all connectors and repair aS necessary Poor ground connection in 1 interconnect cables Put balanced switch in correct position Balanced switch in balanced mode when using unbalanced inputs Replace blown rail fuse Channel sounds distorted 1 Blown rail fuse 1 and low in output inside amplifier Note If unit continues to blow power inlet fuses DO NOT USE A HEAVIER FUSE have it serviced Care and cleaning Under normal use the amplifier will not require any special care Over time you may wish to clean the exterior of the unit by wiping it with a damp cloth to remove any dirt or dust that accumulates on it Do not let any liquid enter the amplifier thru the vents in the top cover You may clean the connectors on the rear panel with isopropyl alcohol annually Page 15 ST1200 series II SPECIFICATIONS Power rating 8 ohms 4 ohms Frequency response Input sensitivity THD S N Input impedance Damping factor Current peak to peak Slew rate Dynamic headroom S N A weighted Voltage gain Line voltage Dimensions O A Weight Power consumption Replacement fuses
3. to the preamplifier Turn the volume on the preamplifier to minimum Turn on the preamplifier then the amplifier in that order Set source on the preamplifier to the playback unit you ve just connected Turn volume up slowly and music should be heard from all channels If this is not the case double check your installation m Should you encounter any problems that cannot be traced to the source or the material being played consult the TROUBLESHOOTING section on page 15 Note When turning equipment off the amplifier should always be turned off first then the preamplifier When turning equipment on the preamplifier should always be turned on first then the amplifier Before turning anything on ensure the preamplifier is at a low volume level Page 14 Troubleshooting POSSIBLE CAUSE PROBLEM No sound on LED not illuminated Power cord not plugged in Power off at AC source AC power inlet fuse blown or faulty Control switch in the wrong position Speaker leads loose or faulty Line stage to amp cables loose or faulty Source to line stage cables loose or faulty Line stage or source not No sound on some or all selected channels on LED illuminated POSSIBLE SOLUTION Reconnect power cord Check AC switch or fuse Check for shorts or overloading Place control switch in proper position Page 5 Tighten repair or replace cable Tighten repair or replace cable
4. Efficient high current transformer for improved dynamics Discrete Circuitry More accurate and three dimensional reproduction of source material Limited Protection Provides short term protection from accidental shorting of output devices and protection from thermal overload Gold Plated Connectors Improve connections for better sound and minimized signal loss and degradation 1 Metal Film Resistors Low noise resistors for better sound and a greater degree of repeatability Medium Current Ability to reproduce demanding recordings Computer Grade Capacitors Large capacity computer grade electrolytic capacitors for extended low frequency control and improved dynamics Rear Panel View M iod R LEVEL L LEVEL SER NO CAUTION Ww RISK OF ELECTRIC SHOCK LO HI LO HI a R IS APPLIED 12 E Ei TOCTRLIN DEFEAT RISQUE DE CHOC ELECTRIQUE ATTENTION RISQUE DE cno MINUS PLUS PLUS i E T o 0 gt a TO PREVENT FIRE OR SHOCK HAZARD DO NOT WARNING expose THis UNIT TO RAIN OR MOISTURE B amp K Components Ltd A C Buffalo NY 14227 2725 Audio Video Systems Made In the U S A LINE Figure A 1 AC fuse holder 5 Line Level outputs 2 AC Input receptacle 6 RCA inputs 3 Speaker outputs 7 Level controls 4 Amplifier control muting input output Page 4 Rear panel description 1 AC fuse holder Holds the AC Line fuse This fu
5. remove the source control group jumper from its present position if necessary and install it on the terminal you wish to select as the source for that channel Make sure it has been inserted on both terminal pins of the jumper modules To complete the configuration the volume group jumper should be placed at either the USE VOL or NO VOL terminal depending on you configuration Note A channel that is not being used in your configuration should have its jumper plugs installed at the default position as shown in Figure F Jumper description Figure G illustrates the jumper modules used in configuring each channel Each jumper terminal location is conveniently labeled as to the source it can be configured to provide Explained further on the following page Page 9 R BUS Along with being the right channel input it is used as the input to the right bus and the right source for the L R BUS Because it is a BUS input any signal input here will appear at the R BUS jumper terminal for both of the ST1200 series II s jumper modules L R BUS Installing a jumper plug at this terminal on either of the two internal jumper modules selects the combined signal being carried by both the left and right inputs If the left bus and right bus are being used to carry stereo right and left channels a jumper plug installed at the L R BUS location will provide a true L R mono output LBUS Along with being the left chann
6. Page 16 60 watts 1 kHz Not recommended 5 Hz 45 KHz 0 77 Volts 0 09 1 kHz 33 2 k ohms 100 20 Amps 14 V usec 1 4 dB 95 dB 28 120 220 240 VAC switchable 17 w X 12 d X 3 75 h 23 lbs 210 watts max 2 3 Amps max current draw 15 watts no input Line 8 Amp 250 Volt Slow Blow Rails 4 Amp 250 Volt Slow Blow Limited Warranty B amp K Components Ltd referred to herein as B amp K warrants your B amp K equipment against all defects in material and workmanship for a period of five years from the date of purchase This warranty applies only to the original purchaser and only to equipment in normal residential use and service Defective equipment must be returned to B amp K prepaid accompanied by sufficient payment to cover the cost of return shipping and handling and will be repaired or replaced at the discretion of B amp K whose decision as to the method of reparation will be final This warranty shall not apply to any equipment which is found to have been improperly installed incorrectly fused misused abused or subjected to harmful elements used in any way not in accordance with instructions supplied with the unit or to have been modified repaired or altered in any way without the expressed written consent of B amp K This warranty does not apply to the cabinet the remote controller or appearance items such as the faceplate control buttons or display lenses nor does it cover any expenses incurre
7. Then adjust them according to your system requirements to match the sound level coming from each speaker This is a rough adjustment for matching different driver impedances Any fine tuning should be done by the preamplifier Page 6 Example When using 4 ohm and 8 ohm speakers together the 4 ohm may sound louder then 8 ohm at a given volume level The level controls on the amplifier are used to match the speakers volume level Clockwise will increase the output Counter clockwise will decrease the output Louder Softer Figure C Inputs RCA type connectors accept line input from the preamplifiers unbalanced output connectors There are two input connectors one for each channel that may be used to connect the amplifier to the preamplifier RCA cable connector Cf Here is a typical input setup From Left output igs Left channel output of preamplifier to another amplifier f B Right channel output to another amplifier From Right output E of preamplifier Left and Right channel output to another amplifier Mono Figure D You will notice the OUT BUS connections shown above You may use these to connect to another amplifier The L BUS OUT carries the same signal as the L INPUT The R BUS OUT carries the same signal as the R INPUT The L R BUS OUT carries the combined signal from the left and right inputs Page 7 Outputs Five way bin
8. annels on the NO VOL jumper terminal Not used Not Used i Not Used Invert Jumper O gt O CH 3 R BUS L RBUS m m LBUS NO VOL USE VOL m m CH 4 R BUS L RBUS m m LBUS USE VOL m m Figure A The speaker output terminals on the ST1200 series II s rear panel must be paralleled in order to complete the setup Simply connect the terminals for both channels together using a jumper wire not supplied with the amplifier Finally connect the speaker cables from the left channels and terminals to the speakers Input your source signal into the left channel input The instructions show the use of the left channel You may also use the right channel if you desire just follow the above instructions using the right channel You may also use the L R BUS to send a mono signal out of the amplifier derived from the left and right channels See below MINUS PLUS PLUS MINUS C OUT R From Left output E of preamplifier OF ii 3G NOT USED R Figure I Figure O Page 11 Bridged application High voltage The ST1200 series II may be bridged to drive a high impedance speaker To use place the source group jumper for both channels o
9. d in shipping the unit to and from the manufacturer s service depot No warranty implied or otherwise created by State law shall extend beyond the terms of this warranty and B amp K shall not be liable for any incidental or consequential damage arising out of a defect in material or workmanship of the unit during the terms of this warranty or thereafter Some States do not allow the exclusion or limitation of incidental or consequential damages and the foregoing exclusions may not apply to you This warranty gives you specific legal rights Your may also have other rights which vary from State to State No agent representative dealer or employee of B amp K has the authority to increase or alter the obligations or terms of this warranty B amp K Components Ltd RETURNING EQUIPMENT No equipment may be returned to B amp K Components Ltd Without aRETURN AUTHORIZATION Should you find it necessary to return equipment to B amp K for any reason aRETURN AUTHORIZATION RA number must be issued by B amp K in respect of the equipment being returned You may request an RA number by calling B amp K at the numbers below We ask that you provide the following information at that time 1 Your name address and phone number 2 The model and serial number of the equipment being returned 3 A description of the problem being experienced Your call will be referred to a Technical Service Representative who will work with you to resolve the proble
10. d 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 m Cable runs are critical in that they must be kept away from sources of power radiation amplifiers power cords heaters etc For the sake of safety they should also be kept out of traffic areas E 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 m When possible use a separate AC power line for the amplifier one that is not shared by any other component in the system of any other house hold component Tip Take a piece of stout 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 Making the connection m Before doing anything ensure that the power switch on the amplifiers front panel is in the off position Again it is recommended that you locate a separate AC power outlet for t
11. ding posts are provided One pair for each channel They are designed to accept a banana type plug or spade lug connector shown below and are color coded for easy identification The red post should always be connected to the speakers jack The black post should always be connected to the speakers jack Wr Spade connector Banana jack Here is a typical amplifier setup Figure Page 8 ST1200 series II s internal bus structure In order to gain access to the internal bus structure you must first remove the top cover Turn the amplifier so the rear panel is facing your The jumper modules may be seen on the circuit board just behind the level controls Below is the default setup for the ST1200 series II amplifier By arranging the jumpers allows you to configure the amplifier for different applications If you wish to use the amplifier as a stereo two channel amplifier you need not change any of the settings E NO VOL E _ USE VOL L RBUS m m LBUS O gt O Eu u Eu u u O LL 2 D R BUS L R BUS L BUS R BUS CH 3 CH 4 Not used Not Used Not Used Invert Jumper Figure lt In order to reconfigure the ST1200 series Is channels
12. el input it is used as the input to the left bus and the left source for the L R BUS Because it is a BUS input any signal input here will appear at the L BUS jumper terminal for both of the ST1200 series II s jumper modules NO VOL If volume control is desired only from the source or if outputs are being combined to obtain higher power the jumper plug should be installed at the NO VOL location USE VOL If volume control is desired at the amplifier beyond that provided at the source a shorting plug is installed at the USE VOL location The USE VOL setting SHOULD NOT be used when channels are bridged or combined Invert Jumper module This is a single jumper module that is set apart up and to the right from the channel jumper modules on the circuit board It provides a special function when the jumper is set on the L pins the left bus signal feeding the left channel will be inverted Note A jumper MUST be installed at L BUS R BUS or L R BUS AND a jumper MUST be installed at NO VOL or USE VOL for the amplifier to operate Page 10 Mono application Medium current The ST1200 series Ms two output channels may be paralleled mono to combine the left and right channels output current This feature allows the amplifier to double its apparent output current To use place the source group jumper for both channels on the L BUS jumper terminal Place the volume group jumper for both ch
13. he amplifier one that is not shared by any other audio component in the system or any other house hold 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 m 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 m Connect the audio cables from your preamplifiers output to the corresponding input connector on the amplifier Page 13 m Connect the wires from your speakers to the appropriate output on the amplifier It is absolutely essential that you observe correct polarity in these connections Example If you connect your right output of your preamplifier to R channel input on the amplifier remember to connect your right front speaker wires to R channel outputs Always observe polarity when connecting speakers connect amplifiers to the speakers and amplifiers to speakers E Double check all connections E Plug the amplifiers power cord into the AC power source Turn the amplifier s power switch on The panel light should be illuminated Leave the preamplifier turned off Before proceeding to the next step turn the amplifier off and wait 30 seconds for the amplifier to discharge Both the preamplifier and amplifier should be off m Connect a playback unit CD VLD Tuner etc
14. ial Double check connections before turning the amplifier on The amplifier can be damaged if polarities are incorrect Damage can occur to your speakers if the power rating of each individual driver is exceeded by the amplifier Ensure that all the drivers in your soeaker system are capable of handling not only the power being delivered by the amplifier but the energy that is likely to be generated during strong passages Turn amplifier off when plugging in or unplugging input and speaker cables The ST1200 series II is equipped with raised feet so that continuous ventilation can be maintained They help to maintain acoustic feedback into the amplifier at a minimum They also 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 ensure proper ventilation If you are at all unsure of what the speaker ratings are contact your dealer Page 2 The ST1200 series II s purpose and function The ST1200 series II is a compact very efficient two channel power amplifier It is designed to be used in all types of audio or audio video systems The term versatile is almost adequate to describe the variance of operational modes the ST1200 series H is capable of providing This
15. is all accomplished through the simple placement of internal jumpers and the paralleling or bridging of its outputs and or linking multiple ST1200 series IIs Here is a listing for some of the many tasks it can be set up to perform e The most obvious function for the ST1200 series II is to take 2 separate audio inputs such as a stereo pair and provide 2 separate amplified outputs Your ST1200 series II has arrived set up in this configuration e With the inputs buffered a line output OUT BUS may be taken from either the L BUS R BUS or L R BUS and sent on to another amplifier This allows for linking of multiple amplifiers e Continuing its versatility the ST1200 series II may be used mono to provide one medium current channel in order to drive a speaker requiring more power As a result of the ST1200 series II s unique bus system the input to the left channel may be inverted thereby allowing the possibility of creating a single high voltage bridged channel from one source through the left bus Design and construction The ST1200 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 include state of the art solid state devices 1 metal film resistors computer grade electrolytic power supply capacitors and a high capacity toroidal transformer Page 3 Features Toroidal Transformer
16. m If it is determined that the unit must be returned for repair an RA number will be issued B amp K Components Ltd 2100 Old Union Road Buffalo New York 14227 1 800 543 5252 or 1 716 656 0023 Page 17 B amp K Components Ltd 2100 Old Union Road Buffalo New York 14227 716 656 0023 www bkcomp com LISTYOUR UNIT INFORMATION HERE MODEL SERIAL DEALER NAME DEALER PHONE SALES PERSON DATE PURCHASED
17. n the L BUS jumper terminal Place the volume group jumper for both channels on the NO VOL jumper terminal Place the jumper module on the L terminal NO VOL jim CH 3 R BUS L RBUS m m USE VOL m m CH 4 R BUS L RBUS m m LBUS USE VOL m u Not Used Not Used Invert Jumper A gt Figure K Finally connect the speakers to the right channels terminal and the speakers to the left channels terminal Input your source signal into the left channel input only the left channel may be used for bridging Note The default position for this jumper plug is set to the L terminal The jumper plug must be installed at this location at all times when not using the L invert function MINUS PLUS PLUS MINUS L From Left output of preamplifier us O G2 NOT USED Figure M Figure A Page 12 System installation There will most likely be a number of cables involved in the installation of your home entertainment system Pre planning is essential in order to maximize system efficiency We recommend the following as a means of helping you reach that goal m Make a diagram of your propose
18. put voltage from the source is critical It must be within the range as indicated on the rear panel 5 24 volts DC is required The amplifier will provide each successive amplifier with a control voltage of 12 volts DC for reliable operation The amplifiers control output may be used as a source of 12 VDC 125 mA for other user applications as well DO NOT POWER MOTORS WITH THIS CIRCUIT Page 5 Rear view of second amplifier with control input Rear view of amplifier with control input From preamplifier Control rear panel control enable output button A 5 24V SIGNAL IS APPLIED TO CTRLIN DEFE ISA PLIED ace eral IN W Daisy chain to o other amplifiers Figure B lf the control function is desired each unit in the system must remain connected at all times and the control must be enabled To enable the control function the CTRL ENABLE button must be out for each controllable amplifier in the system For more information on the amplifiers output status under various control conditions refer to the table below CTALIN CTRL OUT out No Signal OUT No Signal Note The control voltage is for muting control only Each amplifier must be connected to its own source of AC power in order for it to operate Level controls There are two level controls on the back of the amplifier One level control for each channel When using the level controls first start with them turned all the way up clockwise
19. se is an 8 Amp 250 Volt Slow Blow fuse Replace with same type and value fuse only 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 8 4 Amplifier control muting input output To provide remote switching of mute on off of the amplifier Explained further on page 5 5 Line level outputs For connecting signal to another amplifier daisy chaining 6 RCA inputs For connecting signal patch cables interconnects from the preamplifier to the amplifier to pass signal 7 Level controls For adjusting the input level to the amplifier Explained further on page 6 Control muting A control is provided on each ST1200 series II amplifier to allow remote switching of mute on off The preamplifiers control output such as is provided with B amp K series preamplifiers can be utilized to provide a control signal to the ST1200 series II If more than one amplifier is being controlled the control signal can be extended to include each successive unit by simply running an RCA type audio cable from the CTRL OUT connector of the first amplifier to the CTRL IN connector of the next unit commonly referred to as daisy chaining An example of how to connect two amplifiers is illustrated in figure B lf a source other than a B amp K series preamplifier is used to control multiple amplifiers only the control out
Download Pdf Manuals
Related Search