JBL-SUB125A-sub-sm 维修电路原理图.pdf

JBL Consumer Products Inc.250 Crossways Park DriveWoodbury, N.Y. 11797A Harman International CompanyRev B 7/2003SUB125/125aAmplifier/SubwooferSERVICE MANUALRadioFans.CN 收音机爱 好者资料库2Amplifier/SubwooferSUB125GENERAL SPECIFICATIONSSCS125/125a SystemFrequency Response35Hz 20kHz (6dB)SUB125Amplifier . . 75 watts RMSBass. . . . . 8 woofer, bass-reflex enclosureDimensions (H x W x D)14-1/8 x 13 x 13 inches359 x 330 x 330mmWeight . . . 27.5 lbs/12.5 kgRefinements may be made on occasion to existing products without notice,but will always meet or exceed original specifications unless otherwise stated.TABLE OF CONTENTSCOVER.1GENERAL SPECIFICATIONS.2TABLE OF CONTENTS.2SCS125/125a SPECIFICATIONS.3CONTROLS AND THEIR FUNCTION.5SCS125/125a SPEAKER LEVEL CONNECTIONS .6SCS125/125a LINE LEVEL CONNECTIONS .7SUB125 TEST SET UP AND PROCEDURE.8SIMPLE TROUBLESHOOTING.9Service Bulletin JBL9901 .10SCS125/125a PACKING.11SUB125 EXPLODED VIEW.12SUB125 PCB COMPONENT SIDE.13SUB125 PCB SOLDER SIDE.14SUB125 ELECTRICAL PARTS LIST .15SUB125 INTEGRATED CIRCUIT DIAGRAMS.17SUB125 POWER AMP SCHEMATIC DIAGRAM.18SUB125 PRE-AMP SCHEMATIC DIAGRAM.19The SUB125 is part of the SCS125/125a systemRadioFans.CN 收音机爱 好者资料库SCS125/125a SPECIFICATIONSLINE VOLTAGEYes/NoHi/Lo LineUnitNotesUS 120vac/60HzYes108-132VrmsNormal OperationEU 230vac/50-60HzYes207-264VrmsNormal operation, MOMSrequiredAsia 100vac/50HzYes90-110VrmsNormal OperationSpec.UnitLimitsConditionsNotesAmp SectionType (Class AB, D, other)ABABn/aSink required for Class ABLoad Impedance (speaker)4Ohmsn/aNominalZ-curve requiredRated Output Power80Watts801 input drivenTHD Rated Power0.08%0.322k filterTHD 1 Watt0.1%0.522k filterDC Offset10mV-DC20 Speaker OutputsDamping factor200DFn/aInput SensitivityInput Frequency50Hz50Nominal Freq.1 input drivenLine Input220mVrms2dBTo Rated Power1 input drivenSpeaker/Hi Level Input4.26Vrms2dBTo Rated Power(-26dB below Line In).1input drivenSignal to NoiseSNR-A-Weighted100dBA90rel. to rated powerA-Weighting filterSNR-unweighted80dBr60rel. to rated power22k filterSNR 1W-unweighted60dBr55rel. to 1W Output22k filterResidual Noise Floor1.5mVrms2.5Volume max, using RMS reading DMM/VOM (or A/P)Residual Noise Floor1mVrms(max)2Volume max, w/ A/P Swept Bandpass Measurement(Line freq.+ harmonics)Input ImpedanceLine Input15Kohmsn/aNominalSpeaker/Hi Level Input4.7Kohmsn/aNominalFiltersLow Pass (fixed orvariable)fixedLow Pass filter (point orrange)135Hz2dB-3dB PointSlope24dB/Octaven/aQ1.8Dampingn/a2 cascaded 2nd orderfilters of 1.8 &0.7 QSubsonic filter (HPF)31Hz2dB-3dB PointSlope12dB/Octaven/aQ1.4Dampingn/a3Amplifier/SubwooferSUB125Signal Sensing (ATO)Auto-Turn-On (yes/no)yesfunctionalATO Input Frequency50HzfunctionalATO Level2mVfunctional2mV50Hz into Line Inputw/ 1 ch. drivenATO Bandwidth5kHzfunctionalATO-LPF for noiseimmunityDV1 measured 7mV 5kHz. 2mV 1kHzATO Turn-on time5msfunctionalAmp connected and AC on, then input signal appliedAuto Mute/ Turn-OFF Time20minutesfunctionalT before muting, aftersignal is removedPower on Delay time3sec.functionalAC Power AppliedTransients/PopsATO Transient5mV-peak10 Speaker OutputsTurn-on Transient50mV-peak100 Speaker OutputsAC Line cycled from OFF toONTurn-off Transient50mV-peak100 Speaker OutputsAC Line cycled from ON toOFFEfficiencyStand-by Input Power10Wattsn/a nom. line voltagePower Cons.rated power160Wattsn/a nom. line voltageProtectionShort Circuit ProtectionYesfunctionalDirect short at outputThermal Protection65 deg.Cfunctional1/8 max unclippedPowerDV1:Plate=50deg.Cmax.Tab=90deg.C max.T-on=65deg.CDC Offset ProtectionyesfunctionalDC present at SpeakerOut leadsRelay or crowbar (fordriver/fire protection)Line Fuse Rating2Amps2Type-T or Slo BloExternal fuse with UL/SEMKOrated holder4Amplifier/SubwooferSUB1251. Speaker Level Outputs - Connect the Left, Centerand Right speakers to these connectors.2. Speaker Level Inputs - These High Level Inputs arefor receivers that do not have line-level “pre-amp out”or “subwoofer out” jacks. When a pair of main orsatellite speakers are attached to the OUTPUTterminals, they are driven the full range of frequenciesas generated by the music source (receiver, amplifier,etc.)3. Line Level Input - These left and right Line LevelInputs are normally used when the receiver/ processorhas line-level “pre-amp out ” or “subwoofer out” jacks.4. Auto/On Switch - This switch allows you to set theMode of the Amplifier. Turn the switch to Auto tocause it to Auto-matically turn on when it receives asignal and Auto-matically turn off after twenty minuteswithout a signal. If this switch is left “On”, thesubwoofer will always be ON when the power switchis turned On, regardless of input signal.5. Subwoofer Level - This knob controls the volumelevel of the SUB125.6. LED - Red & Green. The LEDs indicate the Modestatus that the subwoofer is in. When the SUB125 isturned OFF neither LED will be lit.The Green LEDwill light when the SUB125 is ON and receiving asignal. The Red LED will light when the amplifier hasnot received a signal for twenty minutes. Thesubwoofer will turn on when your receiver/amplifierbegins playing again.7. Power Switch - This the master power switch. Use it(in Off mode) to disconnect power to the amplifier.8. Fuse - Use only same type of fuses. For the U.S.120V version use only a 2A 250V fuse. For theEuropean 230V version use only a 1A fuse.9. AC Cord5Amplifier/SubwooferSUB125AC 120V,60Hz160WPOWERRLMINMAXFUSESTAND BYONFUSE2A/250VSUB125LINE LEVELINPUTSUBWOOFERLEVELSPEAKER LEVELOUTPUTSPEAKER LEVELINPUTLLCCRRONAUTO123456789CONTROLS AND THEIR FUNCTION6Amplifier/SubwooferSUB125SCS125/125a SPEAKER LEVEL CONNECTIONSSPEAKER LEVELOUTPUTSPEAKER LEVELINPUTLLCCRRSUB125ReceiverLeft FrontLeft SurroundRight FrontRight SurroundCenterLeft FrontLeft SurroundRight SurroundRight FrontCenter7Amplifier/SubwooferSUB125SCS125/125a LINE LEVEL CONNECTIONSSUB125ReceiverLeft FrontSubwooferOutLeft SurroundRight FrontRight SurroundCenterLeft FrontLeft SurroundRight SurroundRight FrontCenterRLRLLINE LEVELINPUT8Amplifier/SubwooferSUB125SUB125 TEST SET UP AND PROCEDUREOUTPUT FROMAMPLIFIERFROM PRE AMPSPEAKERAMPLIFIERCD PLAYERPRE AMPAC VOLT METER ( 6V )SPEAKER UNDER TESTLINE LEVELSPEAKER LEVELRLMINMAXLINE LEVELINPUTSUBWOOFERLEVELSPEAKER LEVELOUTPUTSPEAKER LEVELINPUTLLCCRRONAUTOGeneral FunctionUUT = Unit Under Test1.Connect both right and left line level inputs (RCA) to signal generator and UUT. Use Y-cable if necessary frommono source. VOLUME control should be full counterclockwise.2.Turn on generator, adjust to 200mV, 50 Hz.3.Plug in UUT; red LED should be ON. Turn VOLUME control full clockwise.4.LED should turn Green; immediate bass response should be heard and felt from port tube opening.5.Turn off generator, turn VOLUME control fully counterclockwise, disconnect RCA cables.6.Connect one pair of speaker cables to both high level input terminals on UUT. Cables should be connected toan integrated amplifier fed by the signal generator.7.Turn on generator and adjust so that speaker level output is 3.0V, 50 Hz. Turn VOLUME control full clockwise.8.Green LED should light, immediate bass response should be heard and felt from the port tube opening.Sweep Function1.Follow steps 1-4 above, using a sweep generator as a signal source.2.Sweep generator from 20Hz to 300Hz. Listen to the cabinet and drivers for any rattles, clicks, buzzes or anyother noises. If any unusual noises are heard, remove driver and test.Driver Function1.Remove driver from cabinet; detach + and - wire clips.2.Check DC resistance of driver; it should be 3.3 ohms.3.Connect a pair of speaker cables to driver terminals. Cables should be connected to an integrated amplifier fed bya signal generator. Turn on generator and adjust so that speaker level output is 5.0V.4. Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.9Amplifier/SubwooferSUB125SIMPLE TROUBLESHOOTINGIf there is no sound from any of thespeakers, check the following: Receiver/amplifier is on and a source is playing. Powered subwoofer is plugged in and is either in the “On”or “Auto” position. Check all wires and connections between receiver/amplifier and speakers. Make sure all wires are connected.Make sure none of the speaker wires are frayed, cut orpunctured. Review proper operation of your receiver/amplifier. If thereis no sound coming from one speaker, check the following: Check the “Balance” control on your receiver/amplifier.If the system plays at low volumes butshuts off as volume is increased, check thefollowing: Check all wires and con-nections between receiver/amplifier and speakers. Make sure all wires are connected.Make sure none of the speaker wires are frayed, cut orpunctured. If more than one pair of main speakers is being used,check the minimum impedance requirements of yourreceiver/amplifier.If there is low bass output, check thefollowing: Make sure the connections to the left and right “SpeakerInputs” have the correct polarity (+ and ). Powered subwoofer is plugged in and is either in the “On”or “Auto” position.If there is no sound from the surroundspeakers, check the following: Check all wires and connections between receiver/amplifier and speakers. Make sure all wires are connected.Make sure none of the speaker wires are frayed, cut orpunctured. Review proper operation of your receiver/amplifier and itssurround sound features. Receiver mode must be in Dolby Pro logic, Dolby Digital,or any other mode that creates a surround-sound effect.Even under normal operation, when viewing movies andtelevision, surround sound is not present at all times at ahigh volume - only when the program has chosen to sendinformation there.Service Bulletin JBL9901To: All JBL Service Centers - January 1999 This is considered a Minor repairModel: Sub125 (SCS125 Powered Subwoofer)Subject:Amplifier plate overheating; Blown fusesIn the event you receive a Sub125 (SCS125 Powered Subwoofer) with the complaint “amplifier plate is getting toohot”, or “the unit is blowing fuses”, perform the necessary steps listed below to change the bias current of theamplifier. This procedure should be performed on all Sub125 amplifiers being serviced for any reason:1.Set the subwoofer cabinet on a padded surface with amplifier facing upwards.2.Remove the (14) Philips screws holding the amplifier and inner plastic cover to the cabinet. Four of these 14screws are in each corner, slightly larger and just inside the smaller corner screws.3.Remove amplifier assembly carefully . Do not pull the amplifier out of the cabinet too much; it can disconnectthe speaker wires. (The amp assembly can be laid on one corner of the cabinet for the remainder of theprocedure without disconnecting the speaker wires).4.Carefully pry plastic cover off amplifier assembly. If you are too aggressive Molex connector P104 may bedamaged; speaker wire inside the cover has little extra length. Lift the left side of the cover first to avoiddisconnecting the cable at P104; this connector is located on the right side of the plate inside the cover.5.Once the cover is pulled back, locate VR101. See Figure 1.6.Using a thin Phillips screwdriver 5 or more inches long, set trim pot VR101 to Full CCW position (Minimumlevel). Be gentle to avoid damage to the part.7.If necessary, replace blown line fuse with h/k part# FS1067, (2A Slo-Blo 5 x 20mm GMC type).8.Replace the amplifier in the cabinet; replace all (14) screws to secure the amplifier plate and plastic cover.*9.Functional Test - Set the LEVEL control to minimum (Full CCW). Connect an AC Wattmeter to the AC inputline and turn the unit ON; maximum AC measured power should not be more than 12.5 watts.10. Connect music signal from a CD source and increase volume to a medium level to verify sound from thesubwoofer. Do not increase volume to a point where the unit is driven into clipping. No evidence of distortionand/or rattle inside the box should occur.11. Conduct warm-up for 10 minutes; turn LEVEL control Full CCW or remove signal. Input power as measuredby AC Power meter should not exceed 13 watts. If value exceeds this, re-check pot. VR101 position ifnecessary.12. Add an adhesive label (dot) to the amplifier plate with the letter “a” written on it; if the customers outer cartonis available, add an “a” with a marker to the “SCS125” printing on the carton in all places where it appears.UnmodifiedSub125 (SCS125Subwoofer)Factory ModifiedSub125a(SCS125 Subwoofer)Orange Label onamplifier plate: This area isdesigned to become quitewarm during normaloperationOuter cartonmarked SCS125Outer cartonmarked SCS125a* Alternately, the amplifier may be driven out ofthe cabinet by attaching a 4 ohm 25 watt loadresistor to the output terminals, and using a 50 Hzsine wave input signal adjusted to achieve 7 voltsat the load resistor for the warm-up test.10Amplifier/SubwooferSUB12511Amplifier/SubwooferSUB125SCS125/125a PACKINGOWNERS MANUALAI0360WARRANTYCARDAI0193PLASTIC BAGFOAM SETWP0344WALL HOOKWI0408MURAL STANDWI0409SUB125/125a125SAT SPEAKERSSAT 125OUTER CARTONSCS125 - WB1782SCS125a - WB5349OPTIONAL 125SAT SPEAKER STANDS: FS30012Amplifier/SubwooferSUB125SUB125 EXPLODED VIEW2527412526242421222317141481110122283736353231323193828281629241818132928111311283865428382828282815382937192042HGFFGHEDCBAABCDESUB125/125a PAGE 12 - 1 of 222828283737373636394043363535323132353034333142HGFFGHLMKJILMIJKDESCRIPTIONPART NUMBER#3PLASTIC KNOB700KB800#4POWER SWITCH180PBR12C11S#5FUSE HOLDER15520001#6POWER CORD 120V152U602012POWER CORD 230V152U602015#8POWER TRANSFORMER 120V150E8604104POWER TRANSFORMER 230V150E8604102#15 SLIDE SWITCH AUTO-ON180SMS50126#22 MICAINSULATOR1933M2520#34 JBLLOGOSZ163#36 RUBBER FOOT (SCS125)725RFA800RUBBER FOOT (SCS125a)725RFB800#40 8 WOOFERFTW6080-311#41 SPEAKER TERMINALS1742-CJ9030#42 AMPLIFIER ASSEMBLY (120V) NOT FOR SALEAMPLIFIER ASSEMBLY (230v) NOT FOR SALERef.No.SUB125Exploded ViewSUB125/125a PAGE 12 - 2 of 213Amplifier/SubwooferSUB125SUB125 PCB COMPONENT SIDENETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETPOLYGONSOLIDPOLYGONSOLIDNETNETPOLYGONSOLIDNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETPOLYGONSOLIDPOLYGONSOLIDNETNETNETNETNETNETNETNETPOLYGONSOLIDPOLYGONSOLIDNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETPOLYGONSOLIDNETNETNETNETPOLYGONSOLIDNETNETNETNETNETNETPOLYGONSOLIDNETNETNETNETNETNETNETNETPOLYGONSOLIDNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETNETPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDNETNETNETNETPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYGONSOLIDPOLYG