Infinity-Alpha1200S-ps-sm维修电路原理图.pdf

Alpha 1200sAlpha 1200s Powered Subwoofer SERVICE MANUAL Infinity Systems Incorporated 250 Crossways Park Dr. Woodbury, New York 11797 Rev1 4/2004 RadioFans.CN 收音机爱 好者资料库 - CONTENTS - SPECIFICATIONS .1 DETAILED SPECIFICATIONS .2 CONTROLS. .4 CONNECTIONS. .5 OPERATION. .6 BASS OPTIMIZATION SYSTEM.7 BLOCK DIAGRAM.8 BULLETIN INF2004-01. .9 EXPLODED VIEW.10 PCB DRAWINGS.11 ELECTRICAL PARTS LIST .16 INTEGRATED CIRCUIT/TRANSISTOR DIAGRAMS.21 SCHEMATICS .22 PACKAGE . .26 Infinity Alpha 1200s Basic Specifications Frequency Response 28Hz 150Hz (3dB) Maximum Amplifier Output 500 watts RMS (20Hz 150Hz with no more than 0.1% THD) Crossover Frequencies 50Hz 150Hz, 24dB/octave, continuously variable Driver 12 (305mm) C.M.M.D. Dimensions (H x W x D) 17-1/2 x 17-1/4 x 18-1/4 (445mm x 438mm x 464mm) Weight 45 lb (20.5kg) Optional Accessory Bass Optimization Test TIGHTEN TERMINALS 1. 2. BLACK = STRIPE = NO STRIPE = + RED = + Alpha 1200s 5 INFINITY ALPHA 1200S Power On Plug your subwoofersAC cord into a wall outlet.Do not use the outlets on the back of the receiver. Initially set the Subwoofer Gain (Volume) Control ?to the “min”position. Turn on your sub by pressing the Power Switch ? on the rear panel. Auto On/Standby With the Power Switch ?in the ON position,the Power Indicator LED ?will remain backlit in red or green to indicate the On/Standby mode of the subwoofer. RED = STANDBY (No signal detected,Amp Off) GREEN = ON (Signal detected,Amp On) The subwoofer will automatically enter the Standby mode after approximately 10 minutes when no signal is detected from your system.The subwoofer will then power ON instantly when a signal is detected.During periods of normal use,the Power Switch ?can be left on.You may turn off the Power Switch ? for extended periods of nonoperation,e.g.,when you are away on vacation. Adjust Gain Turn on your entire audio system and start a CD or movie soundtrack at a moderate level.Turn up the Subwoofer Gain (Volume) Control ?about half way.If no sound emanates from the subwoofer,check the AC-line cord and input cables. Are the connectors on the cables making proper contact? Is the AC plug connected to a “live”receptacle? Has the Power Switch ? been pressed to the “On”position? Once you have confirmed that the subwoofer is active,proceed by playing a CD,record or cassette.Use a selection that has ample bass information. Set the overall volume control of the preamplifier or stereo to a comfortable level. Adjust the Subwoofer Gain (Volume) Control ? until you obtain a pleasing blend of bass.Bass response should not overpower the room but rather be adjusted so there is a harmonious blend across the entire musical range.Many users have a tendency to set the subwoofer volume too loud, adhering to the belief that a subwoofer is there to produce lots of bass.This is not entirely true.A subwoofer is there to enhance bass,extending the response of the entire system so the bass can be felt as well as heard.However,overall balance must be maintained or the music will not sound natural.An experienced listener will set the volume of the subwoofer so its impact on bass response is always there but never obtrusive. OPERATION Crossover Adjustments The Crossover Adjustment Control ? determines the highest frequency at which the subwoofer reproduces sounds.If your main speakers can comfortably reproduce some low-frequency sounds, set this control to a lower frequency setting, between 50Hz 100Hz.This will concentrate the subwoofers efforts on the ultradeep bass sounds required by todays films and music.If you are using smaller bookshelf speakers that do not extend to the lower bass frequencies,set the Crossover Adjustment Control to a higher setting,between 120Hz 150Hz. Note: This control will have no effect if the Low-Pass Filter Selector Switch ? is set to “Off.”If you have a Dolby Digital or DTS processor/receiver,the Crossover Frequency is set by the processor/receiver.Consult your owners manual to learn how to view or change this setting. Phase Control The Phase Switch ? determines whether the subwoofer speakers piston-like action moves in and out with the main speakers,0,or opposite the main speakers,180.Proper phase adjustment depends on several variables such as room size, subwoofer placement and listener position.Adjust the phase switch to maximize bass output at the listening position. Alpha 1200s 6 INFINITY ALPHA 1200S Infinitys Bass Optimization System is a simple-to-use,yet sophisticated,low-frequency calibration system.Each Interlude subwoofer contains a parametric equalizer that you can adjust following the directions below.By following these instructions, you can improve the sound of your system. The Bass Optimization System Goal It is a fact of audio that what we hear at low frequencies is determined as much or more by the listening room than by the loudspeaker itself.Placement of the loudspeakers and listeners and the acoustical characteristics of the room surfaces are all important determinants of bass quantity and quality.In most practical situations,there is little that can be done about this, except for patient trial-and-error repositioning of the loudspeakers and listeners.Usually,the practical constraints of a living space and the impracticality of massive acoustical treatment mean that equalization is the only practical solution. Professional sound engineers routinely employ sophisticated measurement systems and equalizers to optimize speakers to the installation.This was never practical for the home audiophile. This is why the Bass Optimization System was created.It enables you to identify the dominant low-frequency response characteristic of your room.Once you know the problem,the Bass Optimization System provides the tools needed to optimize the low-frequency characteristics of the speakers to the room they are in,exactly as the professional sound engineers do it. Preparations Before beginning the bass tests,please check the following: Make sure all three Bass Optimization System controls on the subwoofer are turned fully clockwise. Make sure the loudness contour (if any) on your receiver/ processor/preamp is turned off. Set the receivers/processors tone controls (Bass and Treble) to their center or flat positions. Bypass all surround and effects features of your receiver/ processor/preamp or set to Stereo Bypass. If you are using a multichannel surround processor or receiver,make sure all bass-management features are properly set.The Audio channels should all be set to “Small”or “High- Pass” and the subwoofer set to “On.” Set the Bass Optimization System Selector ? to “On.” For best results,it is recommended that all major furnishings are in place and that all doors and windows in the listening area are in their normal positions.That is,if you normally listen to music with all doors closed,then this is how they should be during this procedure. BASSOPTIMIZATIONSYSTEM To solve a problem,it helps to first identify whether you have one and,if so,what it is.First,play a variety of music and films with energetic bass sounds,like bass guitar,kick drum,keyboards, etc.A kick drum should produce a tight “thump” , not a flabby “boom. ”Bass melody or harmony lines should have notes that are about equally loud.If some notes disappear,or stand out because they are consistently too loud,there is a problem. Disappearing notes have to be handled by moving the listening position,or the loudspeakers,to slightly different locations. Often,but sadly not always,this will be enough.Excesses in bass tend to be most annoying,and energetic resonances that cause “boomy”or “lumpy”bass can be truly aggravating over a period of time.Infinitys Bass Optimization System can fix this. So,the first step is to exercise your music collection,and listen for low-frequency problems that crop up in several different recordings.Something that only happens in one recording is likely to be a problem in the recording it happens! If you identify something that is consistently wrong,select a record that shows it very clearly,and put your CD/DVD player into a repeat mode (A-B repeat is especially helpful,because you can isolate a short musical passage). Set the Bass Optimization System Bandwidth Adjustment Control ? to a middle position (10 clicks from a fully clockwise position) and set the Level adjustment ? for a 6dB (8 clicks from a fully clockwise position).Then,while the music is playing, sit in your favorite chair and have somebody else slowly adjust the Center-Frequency control ? from fully clockwise to fully counter-clockwise.At a certain frequency,you should hear the problem lessen and the overall bass performance improve.When you are satisfied that you have found the best frequency,have your assistant vary the Level ? slowly up and down until you have maximized the improvement.If you have really keen ears, you can also have the Bandwidth Adjustment control ?adjusted for maximum benefit. While the Bass Optimization System allows the listener to fine- tune the bass response to sound best in a particular room,some listeners dont have the skill or desire to adjust their system by ear.In order to facilitate quicker and more accurate results, Infinity has developed an optional test and measurement kit that allows the user to perform a series of measurements and aids him/her in properly setting the Bass Optimization System controls.With the addition of this kit,the Bass Optimization System becomes truly room-adaptive.The kit consists of the following:a test CD,a sound-level meter that is specifically calibrated for low frequencies,and something we call a “Q-Finder,” a device to help find the width of the measured curve and, finally,a measurement template.It works as follows.The listener plays the tones from the test CD and records the relative output level of each test tone,using the sound-level meter,on the provided measurement template.After all the tones are complete, the template contains a response curve for the frequencies below 100Hz.The user simply notes the frequency of the largest bass peak,calculates the correct amount of attenuation,and uses the “Q-Finder”to determine the width of the curve.These three values are dialed into the Bass Optimization System controls located on the speaker.The entire process takes less than twenty minutes. If your dealer does not stock the Bass Optimization System test and measurement kit,you may purchase it directly from Infinity. U.S.residents can visit our Web site at or call 1.800.553.3332.Canadian residents should contact their dealer or call 1.800.567.3275. Alpha 1200s 7 Alpha 1200s 8 Service Bulletin Service Bulletin INF2004-01 March 2004 This is considered a Minor repair To: All Infinity Service Centers Model: Alpha 1200s Subject: Distortion When Coming Out Of Standby In the event you receive an Alpha 1200s subwoofer with the complaint “There is a brief chirping sound, or short oscillation that occurs when the unit is in the AUTO mode, in Standby, when its triggered ON with a music signal”, follow the procedure below to correct this condition: Synopsis: Replace D60 (RLS4148 diode) with a 3.6V Zener Diode; add new Resistor. 1) Remove the amplifier assembly from the subwoofer cabinet (12 Phillips screws). 2) Remove the Plastic Amp Cover from the faceplate (4 Phillips screws). 3) The area of concern is on the Class D Driver PCB (Small Upright PCB on the MAIN AMP PCB). A long, thin, soldering iron tip is recommended. Care must be taken not to damage surrounding components, like large inductor pair L8. 4) Locate, remove D60 (RLS4148 diode); replace with a 3.6V zener diode, Infinity Part# ZMM5227BCT-ND. When replacing D60 the polarity of the new (zener) diode should be reversed. 5) Add new 27K resistor, Infinity Part# 299-27K, to the indicated connections. (This component, electrically, will be in parallel with R37, reducing its value to <22K). Assure the leads do not come into contact with any other connections; insulate the leads if necessary. 6) Replace amp cover and return amplifer assembly to cabinet. 7) Test the subwoofer to assure the distortion is no longer present. 9 Alpha 1200s 7 4 1 2 3 7 5 Alpha 1200s Cabinet - Not For Sale Alpha 1200s Amplifier - Not For Sale (12) 6 (4) (4) (6) Alpha 1200s Alpha 1200s EXPLODED VIEW ITEM NO.DESCRIPTIONQTY.PART NO. 1.Woofer, 12, C.M.M.D. , Shielded, 1336056-001 3.4 ohms 10% 2.Front Grille1339945-001 3.Grille Retainer49330070 4.Port Tube1336799-001 5.Trim Ring1339944-001 6.Rubber Foot Assy4338037-001 ITEM NO.DESCRIPTIONQTY.PART NO. 7.Screw Torx HD, 3.9 x 30mm189412730 (12 Amp Assembly and 6 Woofer) 8.Spike Foot Kit1338076-001 9.Outer Carton1350613-001 10.Top and Bottom End Pads2350615-001 11.Owners Manual1350614-001 12.Warranty Card1335841-002 10 Alpha 1200s 11 Alpha 1200s 12 Alpha 1200s 13 Alpha 1200s 14 Alpha 1200s 15 Alpha 1200s Electrical Parts List Part NumberDescriptionReference Designator AMP ASSY Resistors 021-100401-020MOF Resistor1K 1W J FK TYPER173 021-560305-020MOF Resistor560R 5WS J 8x25 KINKR76 022-005105-020Cement ResistorPN:SQM 0R05 5W J 25x13R2 022-470307-020KNP Resistor470R 7W J (KNP-700S)R78 024-000098-120SMD Resistor0R 1/8W J 0805 R8 024-100498-120SMD Resistor1K 1/8W J 0805 R110,169 024-100598-120SMD Resistor10K 1/8W J 0805 R5,7,16,118,121,122,125,126 024-100698-120SMD Resistor100K 1/8W J 0805 R15,120 024-150498-120SMD Resistor1K5 1/8W J 0805 R119 024-160598-100SMD Resistor16K 1/8W F 0805 R13,13B 024-220498-121SMD Resistor2K2 1/8W J 0805 R17 024-220598-120SMD Resistor22K 1/8W J 0805 R127 024-330498-120SMD Resistor3K3 1/8W J 0805 R77,79 024-330598-120SMD Resistor33K 1/8W J 0805 R4,6,14,60,60B 024-470298-120SMD Resistor47R 1/8W J 0805 R24-27 024-470398-120SMD Resistor470R 1/8W J 0805 R145,155,177,186 024-470598-120SMD Resistor47K 1/8W J 0805 R3,171 024-510498-120SMD Resistor5K1 1/8W J 0805 R48A,48B,48C,48D,48E 024-910498-120SMD Resistor9K1 1/8W J 0805 R63 025-010300-000ThermisterTSE-103 K L:50mmTH1 Capacitors 031-100184-100SMD Capacitor0u01/250V K 0805 X7R C104,119 031-100244-100SMD Ceramic Cap.0u01/50V K 0805 X7R C27,28 031-100344-100SMD Capacitor0u1/50V K 0805 X7R C10,69,112,115,135,138 031-100384-100RSMD Capacitor0u1/250V K 1206 X7R C5,6 031-470144-101SMD Capacitor0u0047/50V K 0805 X7R C1G1 032-100484-200END Mylar Cap.1uF/250V K P:15mmC37,39,30 033-330444-270NPE Capacitor3u3/50V K10 (R)8x13 SBEC114,137 033-680464-270NPE Capacitor6u8/100V K10 (R)1020 GNEC113,136 034-100614-300Electrolytic Cap.100uF/16V M (R)0611 P:2.5C8 034-100625-300Electrolytic Cap., 100uF/25V M (R)6.3x11 P:5C62 034-100695-300Electrolytic Cap.100uF/63V M (R)1012 P:5 C142 034-100895-204Electrolytic Cap.10000uF/63V M R30 x51 85degC1,4 034-220525-300Electrolytic Cap., 22uF/25V M (R) 5x11 P:2.5C25,26 034-33