Pioneer-SX1280-rec-sm 维修电路原理图.pdf

XRABi3RadioFans.CN 收音机爱 好者资料库TypoVolr.rpR.mark!KU120V onlyU.S.A. rnodelKC120V onlyCanads model110v, 120v. 22OV and 240V (Switchsble)Gen6ral exDort models/G110V, 120V, 220V.nd 240V $i,itchsbl6lU.S. Milit8ry modelsix-1 eEtoMODEL SX-1280 COMES IN FOUR VERSIONS DTSTINGUISHED AS FOLLOWS:NOTICE:r This service manual is applicable to the KU and KC types. As to the S and S/G types, please refer to page 81.CONTENTS1. SPECIFTCAT|ONS. 32, CONNECTION DIAGRAM 53. FRONT PANEL FACILITIES 74. LEVEL DTAGRAM . . . . 105. BLOCK DIAGRAM . . . 116. CIRCUIT DESCRPTIONS6.1 Tuner Section .136.2 AF Section .146.3 Power Supply Circuit . .166.4 Proteqtion Circuit. .117, DTSASSEMBLY . 188, PARTS LOCATION8.1 Front Panel View. .208.2 Front View with Panel Removed .218 . 3 T o p V i e w . . . . . . . 2 28.4 Bottom View .298.5 Rear Panel View . . . . . . 249. DIAL CORD STRINGING . . . . . 25RadioFans.CN 收音机爱 好者资料库IO. ADJUSTMENTS10.1 FM Tuner1O.2 AM Tuner10.3 Power Amplifier10.4 Meter Amplif ier11. EXPLODED VIEWS11.1 External Part . , .11,2 lnternal Part12. PACKING13. SCHEMATIC DIAGRAMS, P.C. BOARD PATTERNS AND PARTS LIST13.1 Schematic Diagram and Miscellaneous Parts . .13.2 Tuner Assembly (AWE-092)13.3 Microphone Jack Assembly (GWM-I05)13.4 Cartridge Load Assembly (cWS-134)13.5 Function Switch Assembly (GWS-I33)13.6 EO Amplifier Assembly (AWF-031) . . . . .13.7 Flat Amplifier Assembly (AWG-060113.8 Tone Amplifier Assembly (AWG-059) . . . .13.9 Filter Amplif ier Assembly (AWM-119)13.10 Power Amplifier Assembly (AWH.074)13.11 Resistor Assembly (AWX-I27)13.12 Meter Amplifier Assembly (AWM-I21113,13 Power Supply Assembly AWR-I57) . . . .13.14 Fuse Assembly (AWX-I261 or (AWX-I39113.15 Protection Circuit Assembly (AWM-I23)ADDITIONAL SERVICE MANUAL272930303133404145525354565861646770727477781. SPEC|F|CAT|ONS . . . . . 822. CONTRAST OF MISCELLANEOUS PARTS ,. 823. EXPLODED VIEW . . . . 844. SCHEMATIC DIAGRAMS, P.C. BOARD PATTERNS AND PARTS LISTSchernatic Diagram . . . gs5P Connector Assembly (AWX-062) . . g7Fuse Assembly (AWX-134) .88NO?E: * .Fnse ossembly (AWX-I26) is applicable to the KII type, and AWX-tB9 is for the KC type.4.14.24.3e1. SPECIFICATIONSSemiconductorsF E T S . . . 5l C s . . . . . 6T r a n s i s t o r s . . . . . . 6 1D i o d e s . . . . . . . . 5 0Power Amplifier SectionContinuous power output of 185 watts. perchannel, min., at 8 ohms from 20 Hertz to20,000 Hertz with n0 more than 0.03% totalharmonic distortion.Total Harmonic Distortion (20 Hertz to 20,000 Hertz)Continuous Rated Power Output . .No more than 0.03%90 watts per channel poweroutput, S ohms . . No more than 0.01%I watt per channel Poweroutput, S ohms . . No more than 0.01%Intermodulation Distortion (50 Hertz: 7,000 Hertz = 4:1)Continuous Rated Power Output . . No more than 0.01%90 watts per channel poweroutput, 8 ohms No more than 0.006%1 watt per channel poweroutput,8 ohms No more than 0.005%Frequency Response . . . 5 Hertzto IO,OOOHertzl!aAlnput Sensitivity/ lm pedanceP O W E R A M P I N . . . . . . . l V / 5 O k i l o h m sOutputSPEAKERS . . . . . A, B, C, A+8, B+C, C+ADamping Factor( 2 0 H e r t z t o 2 0 , 0 0 0 H e r t z , 8 o h m s ) . . . . . . . . . . . 3 0Hum and Noise (lHF, short-circ u ited, A Network). . 105d8Preamplifier SectionInput (sens itiv ity/ lm pedance)PHONO I .Cartridge load (capacitance) . . .PHONO 2t 4 t c . . . .2.5mV/50kilohms100, 200, 300, 400pF. . . 2.5mV/50 kilohms. . . 7.5mV/50 kilohmsAUX. . l50mV/50 kilohmsTAPE PLAY1 . 150mV/50 kilohmsTAPE PLAY2. 150mVi50 kilohmsPHONO Overload Level (1kHz;T.H.D: 0.03%)P H O N O l , 2 . . . . . . 3 0 0 m VOutput Level/l mpedanceT A P E R E C l . . . . . . . . 1 5 0 m VT A P E R E C 2 . . . . . . 1 5 0 m VP R E O U T . . . . . 1 V / 1 k i l o h m sTotal Harmonic Distortion(20H2 to 20,000H2, 1V output). . .No more than 0.01%Frequency ResponsePHONO(RIAA equalization). 20Hz to 20,000H2 l0.2dBTone ControlB A S S . . .T R E B L E .FilterL O W . . .sx-,| 480. ,LlOdB (l00Hz) main controla5dB (50H2) sub control. r10dB (1okHz) main controle5dB (20kHz) sub controlH I G H . . .Loudness Contour (Volume control set. 15Hz (12dBloct.). 8kHz (l2dB/oct.)at -40dB position) . . . . +6dB (100H2), +3Og 1l6kli.1Hum and Noise(lH F, short-circuited, A Network)PHONO .AUX, TAPE PLAY , . .Muti ng .FM Tuner SectionUsable Sensitivityt40No .50dB Quieting SensitivityM O N O . .STEREO.Signal-to-Noise Ratio(at 75dBf) . . .STEREO .(at 65dBf) .MONO.STEREO.Distortion (at 65dBf)f00Hz MoNo/STEREO . .o.1%1o.2%lkHz MONO/STEREO . O.1o/o10.15706kHz I4ONO/STEREO . . 0.1YolO.2%Frequency Response . . . 3OHzto 15,O0OHzl33dBC a p t u r e R a t i o . . . . . . . . . . 1 . 0 d BA l ternateC hannel S el ecti vi ty .80d8S puri ous R esponse R ati o . . . .100d8l m a g e R e s p o n s e R a t i o . . . . . . . . . . . . . 9 0 d 8l F R esponse R ati o . .110d8A M S uppressi on R ati o. .55d8Muting Threshold . . 19.2dBf(5gV)Stereo Separation . . . 50dB(lkHz), 35dB(30H2 - 15kHz)S u b c a r r i e r P r o d u c t R a t i o . . . . . . . . . . . 6 5 d 8S C A R e j e c t i o n R a t i o . . . . . . . . . . . . . . 6 5 d 8Antenna Input 300 ohms balanced75 ohms unbalanced. . . 8 0 d 8. . . 95dB. . -20d8AUX, TAPE PLAY. . . 5Hz to S0,OOOHZI?dBAM Tuner SectionS ensit iv it y (lH F, Fe r r i t e a n t e n n a ) . . . . . . . . . .(lHF, Ext. antenna) .SelectivitySignal-to-Noise Ratio. . . . . . .lmageResponse Ratio . . . . . .l F R e s p o n s e R a t i o . . . . . . . . .Antenna. . Built-in300!V/m. . 15pV. . . 30dB. . . 5 0 d 8. . . 40dB. . . . . . 4 0 d BFerrite Loopstick AntennaMisdellaneousP o w e r R e q u i r e m e n t s . . . . . . . . . . 1 2 0 V 6 0 H zPowerConsumption . 430W(UL), 1000VA(CSA)1 100W (max.)Dimensions . 556(W) x i86(H) x461(D) mm21-1 1/l6(w) x 6-1sll6(H) x 17-5l16(D) inWeight Without PackaSe. . 28.7kg (631b 3oz)With PackageFurnished Parts. 32.1kg (701b 10oz)F M T - t y p e A n t e n n a . . . . . . . . . . 1O p e r a t i n g I n s t r u c l i o n s . . . . . . . . 1Hex. Wrench 1*Meacurcd pursudnt to the Federal Trade CommissionsTrade Regulation rule on Pouer Output Claifis forAmplifierc.NO?E:Specificotions dnd the design subject to possible modifico-tion uithout aotice due to improuements.HEX. WRENCHThe accessory hexagonal wrench is provided for removingthe TUNING knob and VOLUME knob or tighteningtheir set screws should they become loose.If required, loosen the set screw by inserting the wrenchinto the hole on the side.of the knob and tuming thewrench counter-clockwise. Be particularly careful not toscratch the front panel when employing the wrench.2. CONNECTION DIAGRAMTurntable I (PHONO 1)AM outdoor antennaCartridge typeplayer (AUX)-t& Grc ou L E!-j-,-Turntable 2 (PHONO 2)300ohmfeederT.tvpc FM anicnnaFM outdoor antenna5six-1 eEloConnect the power plug to the wall outlet because thisreceiver requires a lot ofTape deck 1(TAPE 1)Tape deck 2(TAPE 2Speaker systems A(SPEAKERS ADolby*NR adaptorRightruonmax ial0reL-_,fi./iT IAc12ov m60Hz onlySwitched UnswitchedSWITCHED:(50W max.)Speaker systems B(SPEAKERS BSpeaker systems C(SPEAKERS CA frequently used component(turntable, tape deck, etc.) can beplugged into this outlet. By leav-ing the power switch of thatcomponent in the ON position,power supply to the componentwill be coupled with the receiverswitch operation.UNSWITCHED: Less frequently used components,(Total lOOW which do not require couplecmax power, can be plugged into eitherof these outlets.Lef t Right* Tlre word Dolby is a trademark of Dolby Laboratories Inc.3. FRONT PANEL FACILITIESPOWER SWITCHFlip this switch to the ON position to supply power to thestereo receiver. There will be a short delay when it i; setto ON, because the muting circuit has been actuated tosuppress the unpleasant noise that is sometimes generatedwhen the power is switched on and off.PHONES JACKPlug the headphones into this jack when you want tolisten through your stereo headphones.Release the all SPEAKERS buttons if you want to listento the sound through your headphones only (This meansthat all three buttons will be released).SPEAKERS BUTTPress the button corresponding to the speakers connerrtedto the SPEAKERS terminals (A, B, C) on the rear panel.You can presr two of these buttons to listen to soundfrom two pairs of speaker systems at the same time.NOTE:No ound utill be heard through the speahers if all lhreebuttou are p?esed ot lhe same time.BALANCE CONTROLUse thir control to balance the volume of the left andright chennels. First, however, set the MODE switch toMONO, and adiust so that the sound appears to c,)mefrom somewhere exactly between the two speakers. ll thesound appears to be louder on the right, it means that thevolume of the right channel is higher. Turn the BALAIICEcontrol to the left and adiust. Conversely, if the soundappears to be louder on the left, it means that thevolume of the left channel is higher. Therefore, turn theBALANCE control to the right and adiust. After adjust-ing, return the MODE switch to STEREO.POWER METERSThese power meters allow you to read out the ratedpower level when speakers with a nominal impedance of8 ohms are connected to the receivers speaker terminals.NOTE:These ualues are related to the impedance of thespeahers and they wry accprding to the frequency.In order to find out the exact output leuel, connect an8-ohm dummy load instead of the speahers.FUNCTION INDICATORMEMORY MARKERSThese are very convenient for frequent tuning in to thesame broadcasting station.MUTING SWITCHSet this switch to the -20d8 position to attenuate theaudio output indicated by the VOLUME control by 20d8.There is no need to adiust the VOLUME control if youuse this switch when turning down the audio outputtemporarily and when changing over records or tapes.VOLUME CONTROLUse this control to adlust the output level to the speakersand headphones. Turn it clockwise to increase the outputlevel. No sound will be heard if you set it to -. The scaleis graduated in dB which indicate the attenuation whenthe maximum output level is 0dB.tittlII II IIrtItiill,lI_rEeLE_tw ,oi! - + -.,E;lia- o.,r Er:f o osss$:ffl #OErEn_TONE SWITCHSet this switch to ON when adjusting the BASS andTREBLE controls. In the OFF position, it causes theamplifier to operate with a flat frequency response.FUNCTION BUTTONSPress the function button which corresponds to the pro-gram source. Turn the VOLUME control down firstbefore selecting a different function button while thesound from one program source is being reproduced.FM. . . . . Press this button for FM broadcasts.The FM STEREO indicator tights upwhen the receiver is tuned in to an FMstereo broadcast. The sound is auto-matically received monophonicallyduring FM monophonic broadcasts.TWIN BASS ANDUse these controlsTREBLE CONTRto adjust the bass and the treble.TAPE DUPLICATE SWITCHSet this switch to ON when you want to duplicate or edita pre-recorded tape using two tape decks.TAPE MONTTOR SWTTCHES (1,2)Set switch I to ON with a tape deck which is connectedto the TAPE 1 jacks (REC and PLAY) when you wanr tomonitor the playback or recording of a tape. The tape ona deck which is connected to the TApE 2 jacks (REC andPLAY) can be similarly monitored by setting switch 2 tooN.NOTE:Set these switches to the upper (offl position whenIistening to records or a broadcast.A M . . .A U X . .PHONO 2IMIC . .Press this button for AM broadcasts.Press this button when listening to anaudio component cornected to theAUX input jacks.Press this button when playing arecord on the turntable connected tothe PHONO 2 iacks, or when using amicrophone which you have pluggedinto the MIC iack.Press this button when playing arecord on the turntable connected tothe PHONO i jacks.P H O N O 1 . . . . .NOTES:1. Unplug the microphone from the MIC jach when youdo not intend to use the microphone otherwise youwill not be able to use the PHONO 2 jachs.2. Only one function button should be pressed at atime.Plug your microphone into this lack.The microphone signals are reproduced in mono throughthe left and right speakers.atiI rI t lt lL tt tUttlI It l. ,t :IEEE! ffi gt trED-TUNING METERWhen tuning in to an FM station, the optimum receptionposition is indicated when the metei pointer deflects todead center. Check that the SIGNAL meter pointer hasdeflected as far to the right as possible.SIGNAL METERWhen tuning in to an AM or FM station, the optimumreception position is indicated by the maximum deflec.tion of the meter pointer to the right.FM MULTIPATH BUTTONUse this switch to detect multipath sound when installingthe FM antenna in a position which yields the minimummultipath interference.STEREO INDICATORFILTER15HzBUTTONS. When this button is pressed, a 12dB/oct atten-uation can be provided for frequencies belowl5Hz. This means that you can cancel out noisein the ultra-low frequencies which is generatedby low-pitched rumble from a turntable andother forms of distortion. Although this noisecannot be heard, it can generate intermodula-tion distortion.8kHz . . Press this button to provide a l2dBloct atten-uation at frequencies above 8kHz. Set it to thisposition when you find high-frequency noise,such as that from scratched records, unpleasant.FM 25ps BUTTONPress this button when listening to a *Dolby FM broad-cast; otherwise keep this button at the released position.sx-1 eaoPHONO 1 CARTRIDGE LOAD SWITCHUse this knob to select the input capacitance (pF) inaccordance with the sp.ecified load capacitance of themoving magnet (MM) cartridge connected to the PHONO1 jacks.TUNING KNOBUse this to tune in to broadcasting stations.Select the station and tune for optimum reception byobserving the SIGNAL meter for AM stations and boththe SIGNAL and TUNING meters for FM stations.MODE SWITCHUse this switch for selecting mono or stereo performances.STEREO: Set to this position for normal stereo opera-tion.MONO:When set to this position, the left and rightchannel signals will be mixed and reproducedmonophonically from both speaker systems.FM MUTING BUTTONON (released position) . . . Release this button to sup-press unpleasant inter-stationnoise when tuning in to FMstatio ns.OFF (depressed position) . Depress this. button to pickup weal( stattons.Itt,ill/tIl tt lIt$ 5-,6t*OFOTEn sE FrcErvr Sx-1eAO5. BLOCK DIAGRAMANTENNAt-F MA MLA U XPHONO IPHONO 2M l cRPHONO 2PHONO IA U XL#GND -+716 9.? Ortver Of pOWer Omp. i c,rc le gmpl tf ierr A: 3- ir, rerr - e a n l r n lV e r q . 5 1 ! l r f r Q r- . . . -J_Ss : CARTRIDGE LOAD ( lCO , 200,30C, 400 ) pFg7 : FM MUTING ( on - off )Se : MULTI PATH ( on - off tSs: 0E - EMPHASIS llrs - 75ps )Sro : 0UPLICATE ( on - off )Srr : MONlT0R 1 ( on -off )512: MONlT0R 2 (on-gl! )Srs: ADAPTOR ton-qlStc: M00E ( Stereo - Mono )Sts: MUTING ( -20d8 - oft )Sre : LOUDNESS ( on - orl )Srr: T0NE ( on - off )6. CIRCUIT DESCRIPTIONSRefer to the block diagram on page 11 and theschematic on page 43 for the circuit compositionof this unit.6.1 TUNER SECTIONAM TunerThe AM tuner employs a 2-gangvariable capaci-tor, one IC (HA1197) and one AM ceramic filter.Its block diagram is given in Fig. 1.HA1L97 is a