Marshall_Dual_50 电路图 维修原理图.pdf

820 100K V1-A 330 uF 1 2 3 VOL 2 (dark) 1M LOG VOL 1 (bright) 1M LOG .0022uF .022uF 470K .0047uF 470K 470pF 2.7K 100K 0.68uF 6 7 8 12AX7 V1-B 2.7K 100K 0.68uF 1 2 312AX7 V2-A 10K 6 7 8 V2-B 100pF .022uF 470pF 470K1M LOG VOL 470pF 470K 470K .022uF .001uF 1M LOG 820 100K 12AX7 V3-A 0.68uF 1 2 3 6 7 8 100K TREBLE 470pF C9 .022uF C11 .022uF 33K 1M LOG25K LIN V3-B 250K LIN MSTR VOL BASS MID to Power Amp 100K 47K 1M 47K NOTE 2NOTE 3 NOTE 4 NOTE 1 NOTE 1 Marshall JMP Series 1987 and JCM-800 2204 Switchable Dual Preamps Drawn by Steve Luckey D F E E F NOTE 2JMP series uses .0022uF JCM-800 series uses .022uF 90s Reissue series uses .022uF NOTE 3JMP series uses .005uF JCM-800 series uses 220pF 90s Reissue series uses .0047uF NOTE 4The 0.68uF cap is only present in the JMP 1987 series. NOTE 1Value not critical. Use 33K to 68K. NOTE 5Alternate Switching. Remove the channel selector switch and put a 470K mixing resistor in the JCM-800 signal path as shown. Replace the single input jack with two separate jacks and use an external A/B switch to select channels. 470K NOTE 5 JCM800 2204 PLEXI 1987 收音机爱好者资料库 Ra d i o Fa n s .CN NEUTRALLINE GROUND 3 AMP SLO BLO POWER 6.3 VAC 50/50uF 50uF 10K / 3W10K / 3W C C 0.022 .1 10K 470 1M 1M Presence 5K-L 100K0.022 5600 220K 0.022 220K 82K 5600 47K 1 1 1K/5W 1K/5W SPEAKER (8 OHMS) 1 2 3 8 7 6 5 3 4 1, 8 5 3 4 V4-A V4-B V5 V6 BA From PREAMP 1N4007 BIAS 25K-L 15K BIAS RANGE 220K / 1W +10uF 12AX7 PHASE INVERTER POWER AMPLIFIER .5 AMP 50/50uF PlatesScreensPhase InverterTone Stack Driver 10K / 3W10K / 3W 50uF50uF Plexi preampJCM-800 preamp +10uF 47K ABCDEF .1 47pF Marshall JMP Series 1987 PLEXI Lead Power Amp and Power Supply Drawn by Steve Luckey 1, 8 收音机爱好者资料库 Ra d i o Fa n s .CN 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 T S G Plexi Normal 1M-A Plexi Bright 1M-A JCM 800 1M-A Presence 5K-L Master 1M-A Bass 1M-A Mid 25K-L Treble 250K-L Ground #5 + + 330F 25V 0.68uF 0.022F 0.022F 0.022F 100p + + 50F 450V 0.68uF 470p 0.022F 0.022F + + 50F 450V B+ Node C 0.1F 0.022F 0.1F NFB 0.022F 0.022F V1 Plexi Preamp V2 JCM800 2204 Preamp V3 Tone Stack Driver V4 Phase Inverter V5 PA Output V6 PA Output Gnd #1Gnd #2Gnd #3 0.68uF + + 10F 100V + + 10F 100V B+ to fuse AC from STBY switch Gnd #4 470p 470p 470p BIAS + + 50F 450V E .0047F 630v .0022F 630v F .001F 630v D 47 B C 收音机爱好者资料库 Ra d i o Fa n s .CN 3.13 Turret - drill size is 3/32 Hole for wire pass thru drill size to fit Standoff drill size to fit Dashed lines are underboard jumpers INSTRUCTIONS FOR PRINTING DRILL GUIDE NOTE This drawing contains layers. Insure all layers are turned on for printing. Board size is 3 1/8 X 13. Print two copies of this drill guide FULL SIZE on legal size paper. One copy will be used as a drill guide. The other copy will be used for installing jumpers. Measure the board length of the printout to verify it is 13. Attach to blank board using double sided carpet tape. Use a center punch to put a mark at the cross hairs of each turret, standoff, and hole. Use a 3/32 drill bit to drill all holes. Then enlarge holes as needed for standoff screws and wire pass thru. 13.00