Sphinx-Project2_MK2-pre-sm 维修电路原理图.pdf

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1、SERVICE MANUALPROJECT TWO Mk2PRE-AMPRadioFans.CN 收音机爱 好者资料库SPHINX Project Two Mk2 Service Manual 2 1. UNPACKING.32. SPHINX WARRANTY CARD.33. CONTACTING THE MANUFACTURER.34. THE PRE-AMP AT A GLANCE .4Front panel.4Rear panel .55. OPERATION .6Power on.6Selecting an input .6Adjusting the volume level .6

2、Memory mode.6Power off.66. SPHINX REMOTE CONTROL.7Buttons and LED indication.7Operation.8Selecting without switching.8Batteries.8Encountering problems.87. TECHNICAL SPECIFICATIONS.98. ADJUSTMENT PROCEDURES.10Bias and Offset .10Initial Set-up.10Bias / Offset Adjustment .109. PROBLEMS AND SOLUTIONS .1

3、110. DIAGRAMS AND PARTS LISTS.12Connection Diagram for testing the Project 2 Mk2.13Schematic overview of Project 2 mainboard.14Project 2 power supply overview.15Project 2 power supply.16Project 2 input selection.17Project 2 left pre-amp.18Project 2 right pre-amp .19Project 2 phase inverter.20Project

4、 2 display.21PCB drawings of Project 2 Mk2 .22Partlist pre-amp.23Partlist display.31RadioFans.CN 收音机爱 好者资料库SPHINX Project Two Mk2 Service Manual 3 The Sphinx Project Two Mk2 design principlesThe Sphinx Project Two Mk2 was designed for theever-increasing group of quality-consciousaudiophiles.We are v

5、ery proud of the tradition connected withthe SPHINX name, especially concerning audioquality perfection.This service manual will help you to optimallyservice and repair the Sphinx Project Two Mk2 Pre-Amp.This pre-amp is extremely simple to operate anduses the newest technologies and refined designs.

6、Designs that have successfully been used in theaward winning Project Eight.Features include ultra-linear extremely low-noiseClass A audio circuits, built from the finest hand-selected parts.The signal path is completely balanced from input tooutput, and left and right are totally separated.The power

7、 supply is of a unique design (fully Class-A!) and consists of three completely separate andindependent sections: one for the digital control plusone each for the left and right channel.The ALPS volume control is motor-controlled.All settings and controls can also be accessed fromthe supplied Sphinx

8、 Remote Control.To obtain the maximum quality from this pre amp itis necessary for it to be properly aligned and to beused with top quality audio components, preferablyother Sphinx components.1. UNPACKINGBefore leaving the factory every Project Two Mk2 issubjected to stringent and extensive technica

9、l andexterior quality inspection. This ensures the usermany years of high quality audio from a perfect-looking product.We recommend owners to ship the Project TwoMk2 in its original carton.After unpacking the Project Two Mk2 we thereforerecommend you carefully check it for any transportdamage.If you

10、 find any damage and the product has notbeen shipped in the original carton the ensuringrepair costs will not be covered by the warranty.2. SPHINX WARRANTY CARDTo be entitled to any warranty repairs the ownermust have send the filled out warranty card toSphinx or a distributor where it has been regi

11、stered.Other regulations may apply in your specificcountry: when in doubt, please consult the properauthorities.3. CONTACTING THE MANUFACTURERIn case of any problem not covered in this manualor if you have other questions you may contact theSphinx International Service Department in TheNetherlands (

12、local time: GMT +1h) during officehours at the following numbers:Telephone(+31) 35 602 0302Fax(+31) 35 602 2806E-mailaudionleuronet.nlIt is always very helpful and efficient if you have allrelevant information about the specific product andthe problem ready.Please also refer to the User Manual of th

13、eProject Two Mk2 for information aboutfunctions not described in this manual.It is important to familiarise yourself with thespecial functions, operation and possibilitiesof the Sphinx Project Two Mk2.SPHINX Project Two Mk2 Service Manual 4 4. THE PRE-AMP AT A GLANCEFront panel11. INPUT: With this r

14、otary knob you may selectone of the six inputs.Turn clockwise for an input to the right of theactive one, anti-clockwise for an input to theleft.2. STANDBY: To switch the component on andoff:onLED is greenoffLED is red3. Receptor window for the IR signals from theRemote Control.4. Input selection LE

15、Ds: The input selected withknob (1.) is indicated by one of these LEDs:CD SYMbalanced CD inputCDunbalanced CD inputTUNERunbalanced Tuner inputLINE 1unbalanced line input 1LINE 2unbalanced line input 2LINE 3unbalanced line input 3.5. MUTE: Press this button to temporarily mutethe sound. The red LED w

16、ill light.6. TAPE MON: To select the TAPE IN input. Thered LED will light.7. PHONES: To connect dynamic stereoheadphones.8. VOLUME: This rotary knob adjusts the volumelevel.12354678SPHINX Project Two Mk2 Service Manual 5 Rear panel9. GROUND: You may directly connect the signalgrounds of other equipm

17、ent to the signalground of the Project Two Mk2.10. TAPE OUT: Connect this output to the input ofthe recorder.11. TAPE IN: Connect this input to the output ofthe recorder.12. CD: To connect the cinch signal cable from theCD player.13. TUNER: To connect the cinch signal cable fromthe tuner.14. LINE 1:

18、 To connect the cinch signal cable fromthe signal source for LINE 1.15. LINE 2: To connect the cinch signal cable fromthe signal source for LINE 2.16. LINE 3: To connect the cinch signal cable fromthe signal source for LINE 3.17. CD BALANCED L: To connect the XLR signalcable (balanced cable) from th

19、e left output ofthe CD player.18. CD BALANCED R: To connect the XLR signalcable (balanced cable) from the right output ofthe CD player.19. BALANCED OUT L: To connect the XLRsignal cable (balanced cable) from the left inputof the power amp.20. BALANCED OUT R: To connect the XLRsignal cable (balanced

20、cable) from the rightinput of the power amp.21. OUT 1 L+R: Connect this output with a cinchsignal cable to the input of your power amp.22. OUT 2 L+R: To connect the XLR signal cable(balanced cable) from the right input of theextra power amp or surround processor.23. Control Out: To connect the optic

21、al cablegoing to another Sphinx component.24. Warning!: This shows important informationabout the safety regulations for theProject Two Mk2.25. AC Power: Connect the mains cable to amains power outlet (230 - 240 VAC).26. O / I: This is the mains power switch.27. Fuse holder: Contains a fuse (500 mA

22、slow).28. Selector for power supply voltage (120/240V), (115/230 V).910 11 12 13 14 15161718192021 22 23242526 27 28SPHINX Project Two Mk2 Service Manual 6 5. OPERATIONConnect the mains cable to a mains outlet.Once you have finished connecting all components,you can power on the Project Two Mk2 with

23、 themains switch O / I (26.).The volume control will then automatically turncounter-clockwise and, for a while, the STANDBYLED will blink red/green, after which it will remainred.The pre-amp is now in standby mode.Power onYou switch the amp on with the STANDBY button.That way, all circuits will rema

24、in at optimumoperating temperatures and the audio quality will be100% immediately after switching on. Additionally itsignificantly increases the life span of thecomponent.The pre-amp will select the CD SYM input afterwhich it un-mutes the output.Selecting an inputYou select the input with the large

25、rotary knobINPUT:clockwiseto the right of the selected one,anti-clockwiseto the left of the selected one.Upon reaching LINE 3 or CD SYM you cannot rollover to CD SYM or LINE 3 respectively.As long as you move the knob, only the LEDs willchange: the current selected input remains active.The new input

26、 only becomes active after you haveselected it and released the INPUT knob.You will hear a click. This is caused by the precisionrelays for the inputs: the old one is released whilethe new one is energised.Adjusting the volume levelThe large VOLUME control to the right adjusts thevolume level from O

27、FF to maximum (fully clockwise).The level change is immediate.Memory modeThe Project Two Mk2 has a MEMORY mode: itautomatically selects the last input that was activebefore you switched the component off with thestand-by button.Power offYou switch the Project Two Mk2 off (to stand-by)with the STANDB

28、Y button (2.).SPHINX Project Two Mk2 Service Manual 7 6. SPHINX REMOTE CONTROLThis single Sphinx Remote Control lets you controlall functions: not only of the Project Two Mk2, butalso of all other Sphinx equipment.Only the following buttons and indications on theRemote apply to the Project Two Mk2 (

29、the otherswill not function):Buttons and LED indication1. PRE-AMP: To select the pre-amp.All buttons pressed hereafter will control onlythe pre-amp functions.Note: TUNER and CD have no function.2. STANDBY: Use this button to switch the ProjectTwo Mk2 to stand-by.3. : Pressing this button mutes the o

30、utputs(temporarily) and you will not hear any sound.The red LED will be illuminated. Another presson this button un-mutes the outputs.4. TAPE/MONITOR: Use this button to select theTape IN input. Pressing this button has thesame effect as pressing the TAPE button on thefront panel.Note: The LED of th

31、e selected input (see 4.) willremain illuminated.5. 1 - 6: To select inputs CD SYM to LINE 3(Note: 7, 8, 9 and 0 do not function):1CD SYM balanced CD input2CDunbalanced CD input3TUNER unbalanced Tuner4LINE 1unbalanced line input 15LINE 2unbalanced line input 26LINE 3unbalanced line input 36. ? -butt

32、on: Pressing this big triangular button hasthe same effect as rotating the VOLUME controlon the front panel clockwise. You increase thevolume and the volume control will turnclockwise.7. ? -button: Pressing this big triangular button hasthe same effect as rotating the VOLUME controlon the front pane

33、l anti-clockwise. You decreasethe volume and the volume control will turncounter-clockwise.Note: The ? - and ? -button by default controlvolume of the Project Two Mk2 only, even if youhave selected Tuner or CD.SPHINX Project Two Mk2 Service Manual 8 OperationThe Sphinx Remote is used with several di

34、fferentmodels and can therefore transmit different controlcodes, depending on which model has beenselected with the select buttons (3.).Important: Always press the PRE-AMP buttonbefore you send a command (even if you only haveone Sphinx component).Otherwise it is possible that, although the Remotese

35、nds a signal (LED blinks), nothing happensbecause the transmitted signal is not recognisedby the component.Indoors the Remote may be used up to a distanceof 7 meter, provided there is no strong sunlight inthe room and if you aim the Remote at thecomponent.Always aim the Remote straight at the front

36、panel ofthe component, the maximum offset angle is 30.Selecting without switchingSuppose, for instance, that you would like to selectthe Tuner to Radio 4 without interrupting CDplayback.In that case you momentarily depress (not longerthan 0.5 sec) the TUNER button and the 4 button.If you depress the

37、 select button for longer than 0.5sec, the system will select a different signal source(in our example you will then hear the Tunerplayback).BatteriesThe two batteries have a life span of approximatelyone year during normal use, but shorter when usedmore intensely.Replacement batteries: 1.5 V, penli

38、ght or AAA (oneof these codes is indicated on the packaging andthe batteries). You may also use rechargeable 1.5 Vbatteries.Note: Position the new batteries exactly as shown inthe illustration at the bottom of the batterycompartment, otherwise the remote control doesnot function!Encountering problem

39、s.Remote Control does not workWrong component selectedSelect the correct oneWrong Remote mode (Learninstead of Normal)Select correct modeWrong command programmedRe-program with LearnmodeDistance to componentexceeds 7 mUse Remote at closerrangeAngle between Remote andcomponent exceeds 30Decrease angl

40、eSensor window on front dirtyClean windowBatteries empty or incorrectlyplacedUse new batteries orreplace the old onescorrectlyStrong (sun)light in roomShade off light sourceComponent is not switched on(!)Switch it onMemory erasedRe-program completelyComponent reacts differently than expected ornot a

41、t allWrong component selectedSelect the correct oneComponent or Remote doesnot functionCheck component withits original remoteBatteries in remote emptyUse new batteriesSPHINX Project Two Mk2 Service Manual 9 7. TECHNICAL SPECIFICATIONSBandwidth0 - 500,000 Hz (+0/-3 dB)Phase response error0.5Gain18 d

42、B max.THD+N (IHF-A)0.0015% (2nd harm., 10 - 20,000 Hz)IMD100dBChannel separation100 dBInputs1x XLR balanced5x cinch unbalanced (gold-plated) level, nominal (for 1 V output)0.13 V (-18 dBV) impedanceXLR: 10 kohm / cinch: 50 kohmOutputs1x XLR balanced2x cinch unbalanced (gold-plated)1x cinch Tape (gol

43、d-plated) level9.2 V max. (19.3 dBV) (1 - 100,000 Hz, THD0.002%) impedance10 ohmVolume controlALPS motorised channel imbalanceless than 2 dBSphinx Control1x opticalRemote controlfull functionMechanical decoupling of housingTransrotor absorbing pucksPower supplyexternal, completely stabilisedSupply c

44、apacitance35,200 F totalPower consumption 15 W stand-by17,5 W onDimensions (h x w x d)68 x 482 x 328 mmWeight11 kgThis unit conforms to the EMC interference regulations issued by the EU and to the CE standards.This unit complies with safety regulation VDE 0860 and therefore with international safety

45、 regulation IEC 65.Technical specifications may be changed by SPHINX without prior notice if technical developments make thisnecessary.1998 Audioscript BVSPHINX Project Two Mk2 Service Manual 10 8. ADJUSTMENT PROCEDURESThe Project Two Mk2 only has two parameters thatmight need adjustment:- Bias: to

46、set the bias current and bias voltage ofthe amplifier.- Offset: to set the DC-offset voltage of theoutput.These adjustments might be necessary when theamplifier has been used for a period of time (andsettings have changed due to ageing) or when apart of the Project Two Mk2 have been replaced.After o

47、pening the Project Two Mk2 (by removing the6 screws in the bottom), the following sections willbe visible:- The Mains Transformer.- The Main Print Board with inputs, outputs, thedual power supply and both amps.- The Display Print Board.Bias and OffsetBoth adjustment procedures use the same controls:

48、potmeters P1 & P2 (Left Channel) and potmetersP3 & P4 (Right Channel).At first both Bias parameters should be set (re. thebias current and bias voltage of output transistors).The positive and negative bias are adjustedseparately.This may result in an output DC-offset voltagewhich has to be adjusted

49、afterwards.Proper DC-offset adjustment is very important.A simple trick will greatly increase the accuracy ofthis critical adjustment (see also the drawing titled“Connection Diagram for testing the Project TwoMk2” at page 13).By connecting a DC-coupled power amp to theProject Two Mk 2 outputs and me

50、asuring the offsetat the speaker outputs, the offset is boosted toaround 30 times the original value!Note: We strongly recommend that you use a poweramp with a very low DC-offset, such as the ProjectEighteen.Note: The pre-amp and the power amp should beswitched on at least 1 hour before performing t