Infinity-Alpha1200S-sub-sm 维修电路原理图.pdf

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1、 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 B

2、LOCK 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 wi

3、th 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 & Measurement Kit Infinity Part Number: 33

4、5852-002 Infinity continually strives to update and improve existing products, as well as create new ones. The specifications and construction details in this and related Infinity publications are therefore subject to change without notice. Alpha 1200s RadioFans.CN 收音机爱 好者资料库Alpha 1200sPowered Sub/

5、Plate Amp LINE VOLTAGEYes/NoHi/Lo LineNom.UnitNotesUS 120vac/60HzYes108-132120VrmsNormal OperationEU 230vac/50-60HzYes207-264230VrmsNormal operation, MOMS requiredParameterSpecificationUnitQA Test LimitsConditionsNotesAmp SectionType (Class AB, D, other)Dn/an/aBridge type amplifier, None of the spea

6、ker terminals must be connected to system GND at any time.Load Impedance (speaker)6Ohmsn/aNominalRated Output Power275Watts2201 input drivenLimiter prevents continuous power to exceed 240 Watts.THD Rated Power0.1%122k filterTHD 1 Watt0.1%0.222k filterDC Offset10mV-DC60 Speaker OutputsDamping factor5

7、0DF23Measured at amplifier board Measured at the speaker cable. 200 Watts, measured at speaker output terminals located at the amp board.Input SensitivityInput Frequency30Hz30Nominal Freq.L&R 446mVrms2dBTo 200 WattsSingle input driven, Ap Zo=600 Ohms, LP ONLP Off Mode selected446mVrms2dBTo 200 Watts

8、Single input driven , Ap Zo=600 Ohms, LP OFFSpeaker/Hi Level Input6.225Vrms2dBTo 200 WattsSingle input driven, Ap Zo=600 Ohms, LP ONSignal to NoiseSNR-A-Weighted100dBA85relative to rated powerA-Weighting filterSNR-unweighted90dBr85relative to rated power22k filterSNR rel. 1W-unweighted55dBr50relativ

9、e to 1W Output22k filterResidual Noise Floor0.5mVrms1Volume max, using RMS reading DMM/VOM (or A/P)Residual Noise Floor0.5 mVrms(max)1Volume max, w/ A/P Swept Bandpass Measurement (Line freq.+ harmonics)Input ImpedanceLine Input (L, R,LFE)10KohmsNominalSpeaker/Hi Level Input10KohmsNominalFiltersLP 4

10、th order variable 50-150 Hz 10Subsonic filter (HPF) 3rd OrdeFixed Hz 10Low pass filter OFFFixed Hz 10L or R input driven, LP Filter OFFBOSFrequency Control-Range20-80 Hzfunctional 21 detent pot (0.1 oct. steps)Level Control-Range-14.1 to 0 dB functional 21 detent pot (0.5dB steps)Width(Q) Control -R

11、ange4.5% to 49.5% octavefunctional 21 detent pot (5steps/0.1 octave)Limiter THD at Max. Output PowerYESfunctional Maximum Output PowerFeatures-Auto - On -Off YES-functional No switch provided, Refer to ATO sectionPhase switch 0-180degfunctional Volume pot Taper (lin/log)LOG-functional A TaperVariabl

12、e crossover 50-150 HzYESfunctional 4th Order LP Variable crossoverHP Speaker out YESfunctional Pass Through from the speaker input sectionLP On- Off Select switchYES-functional Disables LP filter, intended for LFE Input ConfigurationLine In (L,R) & LFEYES-functional Dual RCA jackSpkr/Hi Level InYES-

13、functional Binding post connector L&RSignal Sensing (ATO)Auto-Turn-On (yes/no)YESfunctional Auto - on selection switch in Auto ATO Input test frequency50Hzfunctional ATO Level LFE Input2mVfunctional ATO Level Speaker in50mVfunctional Alpha 1200s 2ParameterSpecificationUnitQA Test LimitsConditionsNot

14、esATO Turn-on time2secondsfunctional Amp connected and AC on, then input signal appliedAuto Mute/ Turn-OFF Time15minutes17(T) Time before muting, after input signal is removedAuto turn of time (T) must be 10 T 17 MinutesPower on Delay time3sec.4AC Power AppliedTransients/PopsATO Transient5mV-peakn/a

15、 Speaker OutputsTurn-on Transient50mV-peak2v-pp Speaker OutputsAC Line cycled from OFF to ONTurn-off Transient50mV-peak2v-pp Speaker OutputsAC Line cycled from ON to OFFEfficiencyEfficiency70%65Rated powerNominal Line voltage 120 VACStand-by Input Power12Watts15 nom. line voltageMaximum allowable in

16、put power under nominal Input voltage and frequency, in stand-by mode (HOT or COLD operation).Power Cons. rated power340Watts375 nom. line voltage230 Watts 6.0 Ohms nominal line voltageProtectionShort Circuit Protection YESfunctional Direct short at outputAmplifier should resume operation after shor

17、t circuit condition removal Thermal Protection YESfunctional 1/8 max unclipped PowerTemperature rise in accessible metal parts should not exceed 35K rise for domestic version or 30K rise for European versions (refer to requirements sheet). Unit is protected for over-temperature conditions DC Offset

18、ProtectionYES-DC present at Speaker Out leadsRelay or crowbar (for driver/fire protection), Line Fuse RatingUSA-Domestic 4AmpsType-T or Slo Blo-250 VEU2AmpsType-T or Slo Blo-250 VInternal fuse with UL/SEMKO rated holderAlpha 1200s 3INFINITY ALPHA 1200SRear Panel CONTROLS POWERAC120V 60HZ500WOFFONB A

19、 S S O P T I M I Z A T I O N S Y S T E M20-14.1080FREQUENCYLEVELOFFGREEN: ONRED: STANDBYPHASELINE LEVEL INHIGHLEVELINHIGHLEVELOUTInfinity Systems, Inc.Northridge, CA USAR L+_RLRL180050 150CROSSOVERMIN MAXGAINPOWERON4.549.5WIDTHCAUTIONRISK OF ELECTRIC SHOCKDO NOT OPENWARNING: TO REDUCE THE RISK OF FI

20、RE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE. AVERTISSEMENT: POUR PRVENIR LES RISQUES DINCENDIE OU DE CHOC LECTRIQUE, VITER DEXPOSER CET APPAREIL A LA PLUIE OU A LHUMIDIT.NRTL/CCSA 22.2UL1492Alpha 1200sLP ONLP OFF?Bass Optimization Controls (see page 5)?Bass Optimization Sy

21、stem Selector? Center-Frequency Adjustment?Bass Optimization System Level Adjustment?Bass Optimization System Bandwidth Adjustment?Phase Switch?Low-Pass Filter Selector ?Power Indicator? Crossover Adjustment?Subwoofer Gain (Volume) Control?Line-Level Inputs?High-Level (Speaker) Inputs?High-Level (Sp

22、eaker) Outputs?Power Switch Alpha 1200s 4INFINITY ALPHA 1200SIf your receiver/amplifier does not have subwooferoutputs for the left and right channels or an LFEoutput:CONNECTIONSIf your receiver/processor has subwoofer outputs for the left and right channels: Set Low-Pass Filter to “On. ”NOTE:Some r

23、eceivers have a single subwoofer output (do not confusethis with a single LFE output as described below).In that case,it isrecommended that you use a Y connector (not included) to maximizeperformance.If you have a Dolby* Digital or DTSreceiver/processorwith a low-frequency-effects (LFE) output: Set

24、Low-Pass Filter to “Off” .NOTE:In this case,you do not need to use a Y connector.Simplyconnect the LFE output on your receiver/processor to either the left or right input on the subwoofer.RECEIVER/AMPLIFIERFront Speaker OutputB A S S O P T I M I Z A T I O N S Y S T E M2080FREQUENCYR L1800POWER? ? ?O

25、FFON?-14.10LEVELOFFGREEN: ONRED: STANDBYPHASELINE LEVEL INHIGHLEVELINHIGHLEVELOUT? ? ? ? ?+_RLRL50 150CROSSOVERMIN MAXGAINPOWERON4.549.5WIDTHCAUTIONRISK OF ELECTRIC SHOCKDO NOT OPENWARNING: ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?AVERTISSEMENT: ? ? ? ? ? ? ? ? ? ? ? ? ?Alpha 1200sB A S S O P T I M I Z A T I

26、O N S Y S T E M2080FREQUENCYR L1800RECEIVER/PROCESSORPOWER? ? ?OFFON?-14.10LEVELOFFGREEN: ONRED: STANDBYPHASELINE LEVEL INHIGHLEVELINHIGHLEVELOUT? ? ? ? ?+_RLRL50 150CROSSOVERMIN MAXGAINPOWERON4.549.5WIDTHCAUTIONRISK OF ELECTRIC SHOCKDO NOT OPENWARNING: ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?AVERTISSEMENT:

27、? ? ? ? ? ? ? ? ? ? ? ? ?Alpha 1200sSUBWOOFER ORLFE OUTPUTPOWERAC120V 60HZ500WOFFONB A S S O P T I M I Z A T I O N S Y S T E M20-14.1080FREQUENCYLEVELOFFGREEN: ONRED: STANDBYPHASELINE LEVEL INHIGHLEVELINHIGHLEVELOUTInfinity Systems, Inc.Northridge, CA USAR L+_RLRL180050 150CROSSOVERMIN MAXGAINPOWERO

28、N4.549.5WIDTHCAUTIONRISK OF ELECTRIC SHOCKDO NOT OPENWARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE. AVERTISSEMENT: POUR PR VENIR LES RISQUES DINCENDIE OU DE CHOC LECTRIQUE, VITER DEXPOSER CET APPAREIL A LA PLUIE OU A LHUMIDIT .NRTL/CCSA 22.2U

29、L1492Alpha 1200s Set Low-Pass Filter to “On. ”LOOSEN TERMINALSINSERT BARE END; TIGHTEN TERMINALS1.2.BLACK = STRIPE = NO STRIPE = +RED = +Alpha 1200s 5INFINITY ALPHA 1200SPower OnPlug your subwoofersAC cord into a wall outlet.Do not use theoutlets on the back of the receiver.Initially set the Subwoof

30、er Gain (Volume) Control ?to the “min”position.Turn on your sub by pressing the Power Switch ? on the rearpanel.Auto On/StandbyWith the Power Switch ?in the ON position,the PowerIndicator LED ?will remain backlit in red or green to indicate the On/Standby mode of the subwoofer.RED = STANDBY (No sign

31、al detected,Amp Off)GREEN = ON (Signal detected,Amp On)The subwoofer will automatically enter the Standby mode afterapproximately 10 minutes when no signal is detected from yoursystem.The subwoofer will then power ON instantly when asignal is detected.During periods of normal use,the PowerSwitch ?ca

32、n be left on.You may turn off the Power Switch ?for extended periods of nonoperation,e.g.,when you are away onvacation.Adjust GainTurn 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 fr

33、omthe subwoofer,check the AC-line cord and input cables. Are theconnectors 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 confirmedthat the subwoofer is active,proceed by playing a CD,record o

34、rcassette.Use a selection that has ample bass information.Set the overall volume control of the preamplifier or stereo to acomfortable level. Adjust the Subwoofer Gain (Volume) Control ?until you obtain a pleasing blend of bass.Bass response shouldnot overpower the room but rather be adjusted so the

35、re is aharmonious blend across the entire musical range.Many usershave a tendency to set the subwoofer volume too loud,adhering to the belief that a subwoofer is there to produce lotsof bass.This is not entirely true.A subwoofer is there to enhancebass,extending the response of the entire system so

36、the basscan be felt as well as heard.However,overall balance must be maintained or the music will not sound natural.Anexperienced listener will set the volume of the subwoofer so its impact on bass response is always there but never obtrusive.OPERATIONCrossover AdjustmentsThe Crossover Adjustment Co

37、ntrol ? determines the highestfrequency at which the subwoofer reproduces sounds.If your mainspeakers 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 theultradeep bass sounds require

38、d by todays films and music.If youare using smaller bookshelf speakers that do not extend to thelower bass frequencies,set the Crossover Adjustment Control toa higher setting,between 120Hz 150Hz.Note: This control will have no effect if the Low-Pass FilterSelector Switch ? is set to “Off.”If you hav

39、e a Dolby Digital orDTS processor/receiver,the Crossover Frequency is set by theprocessor/receiver.Consult your owners manual to learn how to view or change this setting.Phase ControlThe Phase Switch ? determines whether the subwooferspeakers piston-like action moves in and out with the mainspeakers

40、,0,or opposite the main speakers,180.Proper phaseadjustment depends on several variables such as room size,subwoofer placement and listener position.Adjust the phaseswitch to maximize bass output at the listening position.Alpha 1200s 6INFINITY ALPHA 1200SInfinitys Bass Optimization System is a simpl

41、e-to-use,yetsophisticated,low-frequency calibration system.Each Interludesubwoofer contains a parametric equalizer that you can adjustfollowing the directions below.By following these instructions,you can improve the sound of your system.The Bass Optimization System GoalIt is a fact of audio that wh

42、at we hear at low frequencies isdetermined as much or more by the listening room than by theloudspeaker itself.Placement of the loudspeakers and listenersand the acoustical characteristics of the room surfaces are allimportant determinants of bass quantity and quality.In mostpractical situations,the

43、re is little that can be done about this,except for patient trial-and-error repositioning of theloudspeakers and listeners.Usually,the practical constraints of a living space and the impracticality of massive acousticaltreatment mean that equalization is the only practical solution.Professional soun

44、d engineers routinely employ sophisticatedmeasurement systems and equalizers to optimize speakers to theinstallation.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 responsecharacteristic of y

45、our room.Once you know the problem,theBass Optimization System provides the tools needed to optimizethe low-frequency characteristics of the speakers to the roomthey are in,exactly as the professional sound engineers do it.PreparationsBefore beginning the bass tests,please check the following: Make

46、sure all three Bass Optimization System controls on thesubwoofer 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

47、 effects features of your receiver/processor/preamp or set to Stereo Bypass. If you are using a multichannel surround processor orreceiver,make sure all bass-management features are properlyset.The Audio channels should all be set to “Small”or “High-Pass” and the subwoofer set to “On.” Set the Bass

48、Optimization System Selector ? to “On.”For best results,it is recommended that all major furnishingsare in place and that all doors and windows in the listeningarea are in their normal positions.That is,if you normally listento music with all doors closed,then this is how they should beduring this p

49、rocedure.BASSOPTIMIZATIONSYSTEMTo solve a problem,it helps to first identify whether you have oneand,if so,what it is.First,play a variety of music and films withenergetic bass sounds,like bass guitar,kick drum,keyboards,etc.A kick drum should produce a tight “thump” , not a flabby“boom. ”Bass melod

50、y or harmony lines should have notes that areabout equally loud.If some notes disappear,or stand outbecause they are consistently too loud,there is a problem.Disappearing notes have to be handled by moving the listeningposition,or the loudspeakers,to slightly different locations.Often,but sadly not