McIntosh-MC250-pwr-sm 维修电路原理图.pdf

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1、MC 250SERVICE INFORMATIONSTARTING WITH SERIAL NO. 23L48MCINTOSH LABORATORY INC. 2 CHAMBERS STREET BINGHAMTON, NEW YORKRadioFans.CN 收音机爱 好者资料库MC 250ELECTRICAL SPECIFICATIONSPower Output:100 watts RMS continuous, 50 watts per channel operatingsimultaneously, into 4 ohm, 8 ohm, or 16 ohm loads.Harmonic

2、 Distortion:Less than 0.25% at rated power output from 20Hz to 20,000Hz.Intermodulation Distortion:Less than 0.25% for any combination of frequencies between20 Hz and 20,000 Hz.Frequency Range:At rated output both channels: +0 to -0.25dB from 20Hzthrough 20,000Hz.Output Damping Factor:Greater than 1

3、0 for any output tap.Input Sensitivity & Impedance:Input sensitivity is 0.5 volts. Input impedance Is 200K ohms.Hum & Noise :Greater than 90dB below rated output.Power Requirements:117 volts AC,50-60Hz, 50 watts at zero signal output, 250watts at rated output.RadioFans.CN 收音机爱 好者资料库MC 250MC 250LEFT

4、CHANNEL POWER OUTPUT PRINTED CIRCUIT BOARD 043-916RIGHT CHANNEL POWER OUTPUT PRINTED CIRCUIT BOARD 043-916INPUT SECTION PRINTED CIRCUIT BOARD 043-795MC 250MC 250S C H E M A T I C NOTESMC 2501. Unless otherwise specified: Resistance values are in ohms, 1/2 watt, and10% tolerance; capacitance values s

5、maller than 1 are in microfarads (F);capacitance values greater than 1 are in picofarads ( p F ) ; inductors are inmi c rohen r i es (H).2. Printed circuit board components are outlined on the schematics by dottedlines. The circled numbers on the dotted lines correspond to the numberson the PC Board

6、 layouts.3. The heavy lines on the schematics denote the primary signal path.4. A l l voltages indicated on the schematics are measured under the followingconditions :a. Use of an 11 megohm impedance VTVM.b. A l l voltages 10% w i t h respect to chassis ground.c. No signal at input terminals.d. AC i

7、nput at 1 1 7 v o l t s , 50/60Hz.e. Front panel controls at:Left GainRight GainModeFully CCWFully CCWStereo5. In units with Serial N o . s below 2 8 L 2 1 : R88, R89, R90 & R91 are used;R49 & R50 are 2200W; R86 & R87 are 160W; and R33 & R34 are 33k.6. In units with Serial N o . s from 28L60 to 37L7

8、5, C5 & C6 are 180pF.Q21 Q25BOTTOM TOPQ19 Q23BOTTOM TOPQ20BOTTOMLOCATION OF TRANSISTORS NOT ON PRINTED CIRCUIT BOARDSQ26TOPQ22BOTTOMQ24TOPMC 250R E P L A C E M E N T PARTSAll parts not listed are common itemsable from radio parts jobbers .Rep1acement parts may be obtained whenby PART NUMBER from:Mcl

9、ntosh Laboratory Inc.Customer Service Department2 Chambers StreetBinghamton, New York 13903(telephone 607 723-3512)SymbolNumberCl1 , 12C27,28C29C47,48C51 ,52C53,54C55,56C57D1 ,2D5,607,8D13,14D15,16D18D20D25,26D27,28D31 ,32FlQ1 ,2Q3, 4Q5,6Q7,8Q9.10Q11 ,12Q15,16Q17,18Q19,20Q21 ,22Elect.Elect.Elect.Myl

10、arElect.Elect.Elect.Elect.si.Si .Si .Si .Si .Si .Si .Si .2.5ASi.Si .si.Si .Si .Si.Si .Si .Si.Si .CAPACITORSDescription470F 4V9300F 45V80/80/1 50/50F200/200/150/150V.47F100F 15V10F 25V640F 25V500F 50VDIODESreference dioderectifier dioderectifier dioderectifier dioderectifier dioderectifier dioderecti

11、fier dioderectifier dioderectifier dioderectifier diodeFUSESc i r c u i t breakerTRANSISTORSNPN transistorNPN transistorPNP transistorPNP transistorPNP transistorNPN transistorNPN transistorPNP transistorNPN transistorPNP transistorobtain-orderedPartNumber066-136066-106066-095064-045066-127066-00506

12、6-157066-137070-046070-022070-022070-O4070-041070-031070-031070-031070-031070-022088-001132-054132-054132-056132-056132-056132-515132-021132-032132-524132-530Q23,24Q25,26RlR2R43,44R57,58R59,60S1 ,2S3TlT2T3Si. NPN transistor 132-070Si. NPN transistor 132-070POTENTIOMETERSLeft gain 134-206Right/mono g

13、ain 134-206RESISTORSWirewound 3.6k 5W 139-065Wirewound .56W 5W 139-048Wirewound .33W 5W 139-071SWITCHESThermal cut out 153-007Modeselector 153-008TRANSFORMERSPower transformer 043-605Output transformer (right) 043-667Output transformer (left) 043-668MISCELLANEOUS ITEMSPlastic feet 017-040Owners manual 038-287Gain control knob 090-017Shipping carton 033-077AC power cord 170-02115C01047S-M1508SCHEMATIC PART NO. 038-508