HHB-Circle5A-spk-sm 维修电路原理图.pdf

Version 1d: 01.99Page Service manualHHB Circle 5A Powered Monitor speakerManual: Version 1d 01.1999This manual is subject to change without notice.Always check with HHB that you are using the latest version.Also available as an Adobe Acrobat V3 file.When printing this file, for clear sharp pictures on a black & while laser, it may be necessaryto adjust your printer drivers Print half tone settings. If you have a 600dpi printer, setting thehalf tone to around 45 lines per inch will give a clean sharp image, where as the default -around 60lpi may give a dark image to pictures.WARNING! DANGER OF ELECTRICAL SHOCKOpening mains operated equipment like the HHB Circle5A incurs a risk of electricshock.DO NOT attempt to open this equipment unless you are qualified to do so, have the neces-sary test equipment and are operating the Circle 5a from an ISOLATED POWER SUPPLY.Ensure that only the correct mains voltage is applied, as marked on the module.NEVER OPERATE OR OPEN THIS SPEAKER IN DAMP OR WET CONDITIONS ANDNEVER ALLOW IT TO BE USED OUTSIDE. ENSURE THAT ALL POWER AND SIGNAL CABLES ARE IN PERFECT CONDITION ANDARE CORRECTLY FUSED.IF IN DOUBT, CONTACT HHB IMMEDIATELY BEFORE PROCEEDING.RadioFans.CN 收音机爱 好者资料库Version 1d: 01.99Page RadioFans.CN 收音机爱 好者资料库Version 1d: 01.99Page 3ContentsPage 1: The cover and warningPage 2: Section 1.0 External arrangement andcomments on connectors/controlsPage 3: General arrangement, notes on testingPage 4: Opening the Circle5A Page 5: Circuit diagram: active filtersPage 6: Circuit diagram: power stagePage 7: Circuit diagram: mains input Page 8: PCB silk screen, top viewPage 9: Parts listPage 10: Fault findingPage 11: Modifications and updates Page 11: OtherTHIS INDEX IS UNDER REVISION DUE TO THEINTRODUCTION OF EARTHED, CLASS 2 VERSIONPage 41.0 ExternalsThis is a view of the external controls onthe Circle5A.The function of the Master Volume controlis to scale down excessive input signals.In a set-up where the signal level isscaled so that set to maximum (fullyclockwide) an input of 0.775vdBv, on theloudest peaks, will fully drive the poweramplifiers.Since many studios use the +4 signalreference as the maximum, it may be anidea to reduce the Master Volume to, say,6 and control the signal at the mixer.There are two input connectors: a masterinput, an isolated XLR following the nor-mal European wiring convention:Pin 1 = shield (ground)Pin 2 = Live, hot, + signalPin 3 = Cold, -, return signalAlso provided is a secondary input: aPhono (Cinch, RCA) connector for unbal-anced systems. The centre pin is signal +,and the connector case is the ground.The selector switch converts the masterinput (the XLR) to unbalanced mode suit-able for the phono input - it does notswitch between the two inputs.Connect to EITHER the XLR or thephono, not both.The metal parts of the panel are isolatedfrom mains ground - the so called doubleisolation standard. Only use the mains cable supplied.Replace the mains fuse with the correcttype.Version 1d: 01.99Page Removing the Circle 5a active module from the cabinetIt is absoluletely essential that before removingthe module you have the necessary tools, aclear space, and sufficient uninterrupted time towork. Rushing leades to mistakes, and mis-tekes can be dangerous and impair the excel-lent performance of your Circle 5a speakers.Ensure that the mains supply is disconnectedand removed from the module, and is notreconnected until the module has been fullyrefitted.Please cover your work bench with s soft mate-rial to protect the underside of your Circle 5sfrom scuffing during removal/replacement of themodule. Also be aware that the module isheavy and that once the screws are loosened,it will tend to drop downwards, and that theheavy aluminium panel of the module will readi-ly chip the softer wood of the cabinet, exposingthe white MDF board under the black paint.You will need one two screwdrivers:1. A 3.0mm cross head screwdriver of theSuperscrew or Pozidrive NOT Phillips type.The Superscrew type has 4 thin grooves intowhich the Superscrew screw driver securelylocates. If the Phillips type is used, the screw-driver will mash the heads, and then it may notbe possible to remove the module from thecabinet.2. A larger size (M4, 4mm, No.2) Superscrewor Pozidrive screwdriver.Removing the screwsPlease follow these instructions exactly. Failureto do so may well destroy your cabinet and/ormodule.First, using your smaller Superscrew driver,check that the screwdriver makes a positive fitto the screws marked 1,2,3,4. Applying as littleforce as necessary, unscrew (anti-clockwise)the four corner machine screws in the order 1,2, 3, 4.These screws locate in metal inserts trapped inthe inside of tha cabinet, and the alignment ofthe module and the cabinet is precise.Then, using the larger screw driver, remove thescrews A, B, C, D, E and, as you loosed screwF, expect the module to drop down. Be ready tocatch it!The module can then be removed a short dis-tance from the cabinet, as the internal connec-tions to the module are on short flexible wires.2.0 General arrangementAll the signal processing circuitry of theCircle5A amplifier module is contained on onedouble-sided plated-through PCB. There are nouser-adjustable parts.Although mains voltages do not appear on thePCB, but care should be taken when examiningand working on the module, since the sec-ondary of the mains transformer (25-0-25 AC)is connected to the bridge rectifiers andsmoothing capacitors on the board.A mute relay prevents power on and power offthumps appearing at the drive units, and givesa silent switch on and off. The correct operationof the mute relay can be detected by carefullylistening to the module as the speaker is pow-ered-up: after approx. 3 seconds a smallmechanical click should be heard in the vacini-ty of the heat sink (from the outside of thespeaker), or from the relay, when the modulehas been removed.The very low level of self noise generated inthe circuitry means that, at idle, the best indica-tion that the speaker is powered and awaiting asignal is the illuminated power on LED, fixed inthe tweeter face plate.The power-on LED is driven from the rectifiedunregulated transformer secondary, and is apositive indication that the transfromer, recti-fiers and smooting capacitors are functioningcorrectly. (It does not, directly, confirm that the12v regulated supply is functioning).Provision is allowed for optional physical isola-tion of the audio grounds by use of an inputtransformer. Fitting the transformer requiresremoval of the PCB.Two presets - one for bass drive level, theother tweeter drive level, and both with a rangeof approx. 2dB are pre-set at the factory andshould not be adjusted.The bass unit is directly driven from a pair of ICpower amolifiers in bridge push-pull mode. Thetweeter is driven from one one IC. NOTE CAREFULLY:DO NOT CONNECT EITHER OF THE BASSOUTPUT TERMINALS TO GROUND SINCETHIS WILL INSTANTANEOUSLY DESTROYONE OR BOTH BASS POWER ICS. THISWILL REQUIRE THE REMOVAL ANDREPLACEMENT OF ONE OR MORE POWERICS, A DIFFICULT AND EXPENSIVE TASK.USE ONLY BATTERY OPERATED ORBALANCED AND FLOATING INPUTISOLATION TO MAINS OPERATEDEQUIPMENT.Photograph of the amp module viewed from the insideVersion 1d: 01.99Page 7Version 1d: 01.99Page Mute-relay modificationA modification involving improving theswitch on/off threshold of the mute relaywas introduced shortly after productioncommenced.This involves the changing of resistorR46, initially fitted as 100kR to 200k or220kR. It is not practical or necessary toremove the PCB, and the fitted resistorcan be cut out, and a substitute resistorcarefully soldered in its place.Version 1d: 01.99Page Photograph of the amp module viewed from the insideTweeter level (HF level) reductionUnder normal operation, the two presets, onefor HF level and the other for bass levelshould not be adjusted as these are individu-ally set at the factory. It is not possible tochange these drive levels unless audio signalanalysis equipment is available.As despatched, the tweeter control is normal-ly fully clockwise (viewed from the perspec-tive as shown above).Imagining that one of the arms of the presetsX is pointing to 5 cclock (fully clockwise).Turning this arm anticlockwise until it pointsto 1 oclock (i.e nearly half way anti clock-wise) reduces the tweeter level by 1dB; turn-ing the arm until it points to 12 oclockreduces the tweeter by 1.5dB and turningfully anticlockwise reduces the tweeter levelby approx. 2.5dB, a very noticeable reductionacross the tweeters operating range.Be sure to return the preset adjuster to theoriginal level or to make a note on the outsideof the module that the Circle 5a is no longerstandard.DO NOT ADJUST THE BASS LEVELADJUSTER as this is individually calibrated,and as shipped will be set and sealed to aunique position.Version 1d: 01.99Page 10Connections to the Circuit boardVersion 1d: 01.99Page 11Version 1d: 01.99Page 8 Version 1d: 01.99Page Version 1d: 01.99Page Harbeth HHB Circle 5 Poweramplifier parts list 1.1999Bez.WertR127 KR227 KR327 KR427 KR5R627 KR7R80 OhmR9100 KR1010 KR1110 KR12130 k / 1%R135,76 K / 1 %R147,32 K / 1%R1525,5 K / 1%R16Trimmer 10 K R1756 KR185,32 K / 1%R193,3 K / 1%R203,3 K / 1%R216,8 K / 1%R226,34 K / 1%R23130 K / 1%R24Trimmer 10 KR2547 KR26100 KR27100 KR28R290 OhmR30100 KR3147 KR3227 KR3310 KR341 KR35R3656 KR3756 KR3847 KR391 KR4027 KR4110 OhmR4247 KR4327 KR441 KR45R46220 K (formerly 100k)R471 MR4810 KR49680 OhmR5016 KR512,2 KR5210 KR53R54R552,2 OhmR56R57C168 pF KeramikC268 pF KeramikC3C4100 nF FolieC5100 nF FolieC64,7 nF MKT / 5%C74,7 nF MKT / 5%C84,7 nF MKT / 5%C947 nF MKT / 5%C103,3 nF MKT / 5%C1115 nF MKT / 5%C124,7 nF MKT / 5%C131 nF MKT / 5%C1468 pF KeramikC1568 pF KeramikC16100 nF FolieC17100 nF FolieC181000 uF/16 V ElkoC191000 uF/16 V ElkoC2068 pF KeramikC21100 nF FolieC22100 nF FolieC23470 nF FolieC2468 pF KeramikC2547 uF / 50V ELKOC2647 uF / 50V ELKOC2747 uF / 50V ELKOC28100 nF FolieC2968 pF KeramikC3047 uF / 50V ELKOC31C3247 uF / 50V ELKOC33100 nF FolieC34470 nF FolieC3568 pF KeramikC3647 uF / 50V ELKOC3747 uF / 50V ELKOC38C3947 uF / 50V ELKOC404,7 uF / 50V ELKOC414,7 uF / 50V ELKOC42100 nF FolieC43100 nF FolieC44470 nF FolieC45100 nF FolieC464,7 uF / 50V ELKOC474,7 uF / 50V ELKOC48100 nF FolieC49100 nF FolieC5068 pF KeramikC5168 pF KeramikC521 nF MKTC53470 nF FolieC544.700 uF / 40V ELKO(Philips; Pan )C554.700 uF / 40V ELKO(Philips; Pan )D1BZY 18VD2BZY 18VD3D4BY 500 oder BY 550D5BY 500 oder BY 550D6BY 500 oder BY 550D7BY 500 oder BY 550D81N4148D91N4148T1BC546T2BC546T3BD135, inverserEinbauV1NE5532V2NE5532V3NE5532V4NE5532V57912V67812V7TDA7294VV8TDA7294VV9TDA7294VPoly-Switch Poly-Switch RM5mmBR4Brcke oder 0 OhmBR5Brcke oder 0 OhmBR6Brcke oder 0 OhmLBR1 0 OhmLBR2 0 OhmLBR3 0 OhmLBR4 0 OhmRelay YW2-SN12Version 1d: 01.99Page JP3JumperJP4JumperJP5JumperLED green2-pol. Berg-Stiftleiste 76384-302Overload2-pol. Berg-Stiftleiste 76384-302LS14,8mm FlachsteckerLS24,8mm FlachsteckerLS44,8mm FlachsteckerOUT2 4,8mm FlachsteckerVCC1 4,8mm FlachsteckerVCC2 4,8mm FlachsteckerGRND4,8mm FlachsteckerMechanical partsKhlblech315 x 196 x 4 mmCinchbuchse Monacor T-706GKabelsatzKaltgerte, Poti; XLRLackierungPlatte , Khlk. , BgelKhlkrperSK 81-300-ALIsolierfolie25 x 50mm keratermTrafo 120VA , 2x25V Netzanschl. 6762B , HeilSicherung1,6 A trgePotiMonacor VRB-141M50 KnpfeMonacor KN-11/SWXLR-Anschl. 3 pol BuchseSchraubenM3x16 , M3x8 , M4x8, M6x70SchalterSchadow ZFAFA200BKGN2UEEBgel 272 x 30 mm 8QAbstand-MetallAbstandshalter3 x 10, DR701PAluwinkel2 St.Bearbeitung KhlkrperMontageSubject to change without noticeE&OEVersion 1d: 01.99Page