Ampeg_J12B 电路图 维修原理图.pdf

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1、AMPEG J-12B JET Schematic redrawn by Steve Luckey on October 10, 2012 6 4 5 47K 1M 2.2K 100uF 120K .02 .002 TONE 500K VOLUME 1M C .01 V1B 6SL7 .02 120K 1W 1 2 3 V2 6SL7 C A .02 500/10W 270K270K 1K SPEAKER (8 OHMS) 5 8 3 4 8 5 3 4 B 20 1K V3 6V6 V4 6V6 6 4 5 100 1K 220X C 120K 1W 470K510K .02 5-10K 3

2、00pF 470K NEUTRALLINE GROUND 3 AMP SLO BLO POWER 6.3 VAC filaments 5 VAC 202020 1K / 10W22K / 1W A 364 VDC B 357 VDC C 264 VDC 366 VAC 366 VAC 6 8 2 4 V5 V4V3V2V1 22 77 100 100 5Y3 88 77 oChanged V1B grid resistor from 5.6M to 1M, re M12. oReplaced V2 with lower gain 6SN7. o250/10W cathode resistor

3、replaced with 500/10W. oSeveral Tremolo circuit mods. (see Trem Mod sheet) Conversion notes 122.5VAC 382V 382V 380V 380V 27 0V 0V 0V 0V 3.4V 3.1V 86V 80V 166V 2V 0V 2 1 3 270K 270K .05.05 .05 .1 B 120K 500k Speed 120K V1A 6SL7 1M Intensity X 2.2M LED Footswitch .05 Slow 3.2-5.8Hz Fast 4.5-10.8Hz 47K

4、 收音机爱好者资料库 Ra d i o Fa n s .CN 2 1 3 270K 1M 270K .05.05 .05.1 B X 120K V1A 6SL7 1K 25 Footswitch 2 1 3 270K 270K .05.05 .05 .1 B 120K 500k Speed 120K V1A 6SL7 1M Intensity X 2.2M LED Footswitch .05 Slow 3.2-5.8Hz Fast 4.5-10.8Hz 47K oReplaced V1A cathode R/C with yellow LED for more trem signal. oM

5、oved Speed control to first R/C phase shift node. oAdded Speed switch for greater speed range. oReplaced tremolo output 1M resistor with 1M Intensity pot. oTremolo footswitch rewired same as Fender 6G16 to allow fast start with no pops. Tremolo modification notesOriginal J-12-B circuit 500k Speed 12

6、0K 收音机爱好者资料库 Ra d i o Fa n s .CN 500KA TONE Board Dimensions:2 5/16 x 7 11/16 Designed by:Steve Luckey Date:10/16/2012 Ampeg J-12B Jet 1 2 3 4 6 7 8 5 1 2 3 45 6 7 8 V4 6V6V2 6SL7V1 6SL7 1 2 3 45 6 7 8 1 2 45 6 7 8 3 B V3 6V6 + + 100F 100V + + 25F 25V C B .1F 630v .047F 400v.047F 400v .047F 400v + + 100F 100V NFB .022F 630v .022F 630v .022F 630v 300p GND #1 + + 25F 25V T S G 1MA INTENSITY 1MA VOLUME 500K SPEED .0022F 630v to V2-1 .022F 630v C GND #2 .01F 630v 500 10 watt FS Com .047F 400v Speed Range LED 收音机爱好者资料库 Ra d i o Fa n s .CN