Sphinx-Myth3-int-sm 维修电路原理图.pdf

1. SERVICE MANUALMYTH 3INTEGRATEDSTEREO AMPLIFIERRadioFans.CN 收音机爱 好者资料库SPHINX Myth 3 Service Manual 2 1. UNPACKING.32. CONTACTING THE MANUFACTURER.33. THE AMP AT A GLANCE.4Front panel.4Rear panel .54. OPERATION .6Power on.6Selecting an input .6Tape button.6Adjusting the volume.6Standby button.6Power off.6Amplifier switches to Protection Mode. .65. SPHINX REMOTE CONTROL.7Buttons.7Operation.8Selecting without switching.8Batteries.8Encountering problems.86. TECHNICAL SPECIFICATIONS.97. ADJUSTMENT PROCEDURES.10Bias.10Offset .108. PROBLEMS AND SOLUTIONS .119. DIAGRAMS AND PARTS LISTS.12Measurement Set-up .13General Overview Myth 3.14Schematic Diagram Power Supply.15Schematic Diagram Input / Output.16Schematic Diagram Amplifier Left.17Schematic Diagram Amplifier Left.18Schematic Diagram keyboard.19Schematic Diagram control.20Parts List.21RadioFans.CN 收音机爱 好者资料库SPHINX Myth 3 Service Manual 3 The Sphinx Myth 3 designThis service manual will help you to optimallyservice and repair the Sphinx Myth 3 IntegratedStereo AmplifierThis integrated high-end stereo amplifier is ofdiscrete design throughout (no ICs are used).The Myth 3 uses a passive pre-amp.The power amp uses specially selected powerFETs with a power bandwidth of over 20 MHz, avery fast slew rate and an unsurpassed phaselinearity over the power bandwidth.Each channel uses two 120W/10A FETs andoperates as a pure current source with a very lowimpedance. The amplifiers are therefore very stableand can effortlessly drive every type and format ofloudspeaker at maximum quality (even the mostcomplex ones, such as electrostatic andmagnetostatic.).The amp outputs are sent to the loudspeakerconnectors via heavy duty, completely gold-platedrelays.To obtain the maximum quality from this integratedamp it is necessary to use it with top quality audiocomponents, preferably with other Sphinxcomponents.1. UNPACKINGBefore leaving the factory every Myth 3 is subjectedto stringent and extensive technical and exteriorquality inspection.This ensures you will enjoy many years of highquality audio from a perfect-looking product.After unpacking your Myth 3 we thereforerecommend you carefully check it for any transportdamage.In case of damage: please contact your Sphinxdealer immediately and retain all packing materialsfor possible proof of damage and possible claims.Even if the component is in perfect condition youshould still keep the packing materials. If you needto transport your Myth 3 at a later time it will be bestprotected by the original packing materials.2. 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 (local time: GMT +1h) during officehours at the following numbers:Phone:(+31) 35 602 0302Fax:(+31) 35 602 2806E-mail:audionleuronet.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 theMyth 3 for information about functions notdescribed in this manual.It is important to familiarise yourself with thespecial functions, operation and possibilitiesof the Sphinx Myth 3.SPHINX Myth 3 Service Manual 4 3. THE AMP AT A GLANCEFront panel1. PHONES: To connect dynamic stereoheadphones.2. CD: To select the CD input.3. TUNER: To select the TUNER input.4. LINE 1: To select the LINE 1 input.5. LINE 2: To select the LINE 2 input.6. TAPE: To select the TAPE IN input.As soon as you have pressed one of the buttons2. to 6. the corresponding red LED next to it willlight.7. STANDBY: To switch the component on and off.When the component is off (standby) this isindicated by the red LED.8. Sensor window for the IR signal from theRemote Control.9. VOLUME: With this motor-controlled knob youmay adjust the volume of the loudspeakers.The volume can be controlled manually or via theRemote Control.SPHINX Myth 3 Service Manual 5 Rear panel10. LINE 2: To connect the cinch signal cable fromthe signal source for LINE 2.11. LINE 1: To connect the cinch signal cable fromthe signal source for LINE 1.12. TUNER: To connect the cinch signal cable fromthe tuner.13. CD: To connect the cinch signal cable from theCD player.14. TAPE OUT: Connect this output to the Input ofthe recorder.15. TAPE IN: Connect this input to the output of therecorder.16. RIGHT OUTPUT: To connect the cable from theright loudspeaker:red+black-17. LEFT OUTPUT: To connect the cable from theleft loudspeaker:red+black-18. Manufacturers label: This shows importantdata for the component, such as serial numberand mains power voltage.19. AC Power: Connect the mains cable to a mainspower outlet (100 - 240 VAC).20. Fuse holder: Contains a 3.15 A slow type fuse.21. ON/OFF: This is the mains power switch.10 1112 1314 15161718192120SPHINX Myth 3 Service Manual 6 4. OPERATIONOnce you have finished connecting all components,you can switch on the Myth 3.Connect the mains cable to a mains outlet.Turn the volume control to off (fully counter-clockwise).Power onSwitch the Myth 3 on with the ON/OFF switch (21)on the rear panel.The red LED next to the STANDBY button will blink.After a few seconds the CD input is selected: the redLED next to CD (2) will light.The Myth 3 is now switched on and ready for use.You can leave the amp on. That way all circuits willremain at optimum operating temperature and theaudio quality will be 100% immediately afterswitching on. Additionally it significantly increasesthe life span of the component.Only if the amp will not be used for a longer periodyou might switch it off with the ON/OFF switch (21)to save energy.Selecting an inputSelect the input with one of the buttons 2. to 6.As soon as you have selected an input, the red LEDnext to the button will light.CD: To select the CD input.TUNER : To select the TUNER input.LINE 1: To select the LINE 1 input.LINE 2: To select the LINE 2 input.Tape buttonPressing the TAPE button in the front panel (6)selects the TAPE IN input.After you press PLAY on the recorder you will hearthe recorded signal.If you record a tape this button lets you compare theinput signal (as selected with button 2., 3., 4. or 5) tothe signal from the recorder:IN (LED red)signal from tapeOUT (LED off)signal from selected inputWhen using a 3-head recorder you can thereforecompare the original signal with the actual recordedsignal (youll hear the off-tape signal which might beslightly delayed).Adjusting the volumeUsing the large VOLUME control (9) you can adjustthe sound level from the loudspeakers.This volume control is motor-controlled. If you adjustthe volume on the Remote Control the knob will turnautomatically. The position of the knob alwayscorrectly indicates the set volume.Standby buttonThe STANDBY button (7) temporarily mutes thesound from the loudspeakers: the red LED will light.Another press on the button un-mutes the sound, theLED extinguishes.You may also use this button when you listen onheadphones and would like to switch theloudspeakers off. The Mute function has no influenceon the signal to the headphones.This function can also be controlled using theRemote Control.Power offSwitch the Myth 3 temporarily off (to stand-by) withthe STANDBY button (7).When the Myth 3 will not be used for a longer period,you may switch it off completely with the ON/OFFswitch (21).Amplifier switches to Protection Mode.Indication: the Standby LED blinks rapidly and thevolume control turns automatically to “zero” (fullycounter clockwise).Note: Switch power off with the ON/OFF switch (21)and wait for at least 60 seconds. In the mean time,check all loudspeaker cables for shorted wires! If youfind any, remove the short-circuit to insure fault-freeconnection.Now switch the power on with the ON/OFF switch. Ifthe amplifier itself is not defective, it will operatenormally again after 30 seconds.SPHINX Myth 3 Service Manual 7 5. SPHINX REMOTE CONTROLThis single Sphinx Remote Control allows you tocontrol all functions: not only of the Myth 3, but of allother Sphinx equipment.Only the following buttons and indications on theRemote apply to the Myth 3 (the others will notfunction):Buttons1. PRE-AMP: To select the amp. All buttonspressed hereafter will control only the ampfunctions.2. STANDBY: Use this red button to switch theloudspeaker outputs of the Myth 3 off (standby).3. 1 - 4: To select inputs CD to Line 2 (Note: 5 to 0do not function):1CD2Tuner3Line 14Line 24. TAPE/MONITOR: Use this button to select theTape IN input.5. + button: Pressing this button has the sameeffect as rotating the VOLUME control on thefront panel clockwise. You increase the volume.6. button: Pressing this button has the sameeffect as rotating the VOLUME control on thefront panel anti-clockwise. You decrease thevolume.SPHINX Myth 3 Service Manual 8 OperationThe Sphinx Remote is used with several differentmodels and can therefore transmit different controlcodes, depending on which model has beenselected with the select buttons (1).Important: Always press the PRE-AMP button beforeyou send a command (even if you only have oneSphinx component).Otherwise it is possible that, although the Remotewill send a signal, nothing happens because thetransmitted signal is not recognised by thecomponent.Indoors the Remote may be used up to a distance of7 meter, provided there is no strong sunlight in theroom and if you aim the Remote at the component.Always aim the Remote straight at the front 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.The same procedure is used for the other systemcomponents.How to operate the Remote Control with the differentSphinx components will be explained in thecorresponding User Manual of each component.BatteriesThe four batteries have a life span of approximatelyone year during normal use, but shorter when usedmore intensely.Replacement batteries: 1.5 V, model micro or penliteor LR03 or AAA or AM4 (one of these codes isindicated on the packaging and the batteries). Youmay also use rechargeable 1.5 V batteries.Note: Position the new batteries exactly as shown inthe illustration at the bottom of the batterycompartment, otherwise the Remote will notfunction!Encountering problems.Remote Control does not workWrong component selectedSelect the correct oneDistance to componentexceeds 7 mUse Remote at closerrangeAngle between Remote andcomponent exceeds 30Decrease angleSensor 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 onComponent reacts differently than expected ornot at allWrong component selectedSelect the correct oneComponent or Remote doesnot functionCheck component withits original remoteBatteries in Remote emptyUse new batteriesSPHINX Myth 3 Service Manual 9 6. TECHNICAL SPECIFICATIONSBandwidth10 - 103,000 Hz (+0/-3 dB)Phase response error2x 50 W into 8 (17.0 dBW), THD 2x 68 W into 4 (18.3 dBW), THD 2x 66 W into 2 (18.2 dBW), THD 0.01%3Output voltage / current, max.20 V / 10 ATHD+N (IHF-A)0.006% (2nd harm., 10-20,000 Hz)IMD100 dBChannel separation70 dB (1 - 20,000 Hz)Slew rate24 V/sDamping factor525 (1 - 1,000 Hz)Inputs cinch, unbalanced1x Line 2, 1x Line 1, 1x CD, 1x Tuner, 1x Tape level, nominal1.25 V impedance20 kOutputs cinch1x Tape headphones1x 6.3 mm stereo jack, adjustable level clamp1x loudspeaker L, 1x loudspeaker RSupply capacitance18,800 F totalPower consumption550 W max. (57.5 W standby)Dimensions (h x w x d)110 x 434 x 330 mmWeight7 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 regulation IEC 65.Technical specifications may be changed by SPHINX without prior notice if technical developments make thisnecessary.1999 Audioscript BVSPHINX Myth 3 Service Manual10 7. ADJUSTMENT PROCEDURESThe Myth 3 is an integrated amplifier, meaning thepre-amp and power amp sections are combined intoone cabinet.The Myth 3 only has two parameters for eachchannel (so four in total) that might needadjustment:- Bias: to set the bias current and bias voltage ofthe amplifier for normal use.- 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 Myth 3 have been replaced.Attention:When re-adjusting any setting please ensure thatthere is no loudspeaker connected to the output!Otherwise the loudspeaker may be seriouslydamaged.Attention:The amplifier is able to generate high outputvoltages of over + or -40 V.Please be very careful during the adjustments!BiasWith this procedure you set the proper bias level forthe power FETs. This ensures their Class Aoperation at low power levels.Connect the amplifier according to the drawing“Measurement Set-up” (page 13).The input of the amplifier must be shorted (by wayof the MUTE function of the oscillator). Switch the amplifier ON and wait until it hasreached the proper working temperature Set the millivolt-meter to the DC-range. Place the two measuring clips of the meteracross one of the source resistorsLeft: R30L, R31LRight:R30R, R31R(refer to schematic on page 17/18). The level for each should be 8 mV DC (2 mV).If not: adjust potmeter P2L (Left) or potmeterP2R (Right) until the level is 8 mV. Repeat this procedure after 20 minutes tofinalise the adjustment. Switch the oscillator on and set it to 1 kHz and alevel of 0 dBV (1 V). Check the distortion with a THD analyser: itshould be conform to the specified value (0.01%IHF-A 1 20 kHz 50 W into 8 ohm).If this is correct the procedure is finished. You may now switch off the amplifier or continuewith another adjustment procedure.OffsetThe Offset adjustment procedure minimises the DCoffset value of the amplifier output. This DC offset isimportant when capacitive loads are used, such aselectrostatic loudspeakers. These loudspeakersoften use a very low-impedance step-uptransformer. The amplifier sees this load as ashort for the DC voltage.Connect the amplifier according to the drawing“Measurement Set-up” (page 13).The input of the amplifier must be shorted (by wayof the MUTE function of the oscillator). Switch the amplifier ON and wait until it hasreached the proper working temperature. Set the millivolt-meter to the DC-range. Place the measurement clips of the meter overthe output terminal. The level should not exceed +1 or -1 mV DC.If it does: adjust potmeter P1L (Left) or P1R(Right) until the level is within this range. Repeat this procedure after 20 minutes tofinalise the adjustment. Switch the oscillator on and set it to 1 kHz and alevel of 0 dBV (1 V). Check the distor