November_01 电路图 维修原理图.pdf

A 2.5 ohm SPEAKER .022uF 100K .022uF 100K 15K 5.6K 2 2 3 7 3 2 7 9 B 1 3 5.6K V3 12AX7 V4 EL84 V5 EL84 C 1K/5W C 7 8 6 47047K 1M 1M 0.022uF .022uF 15K 9 B 1K/5W 1 BIAS BIAS COM Rk 150/5W Ck 250uF 1 BIAS MODE CathodeFixed F 5K LIN PRESENCE 0.1uF 22K FEEDBACK ONOFF NOTE 4 3.15 VAC 32/32uF32/32uF 10K / 5W A 348 VDC B 346 VDC C 288 VDC 275 VAC 275 VAC 6 8 4 V6 V5V4V2V1 4455 4499 55 5Y3 2 V3 4 9 5 NEUTRAL LINE 2 AMP SLO BLO 5 VAC 47uF 10K / 2W10K / 2W D 248 VDC E 233 VDC 25uF9.1K / 1W 200K / 1W 3.15 VAC +15 VDC 100K / 1W + 25uF BIAS ADJ 10K 6.8K 47K 25uF F -15VDC 1N4007 All filaments are operated at 6.3 VAC and floated to +15 VDC for hum rejection. 1M LOG MSTR VOL Pwr Amp InPre Amp Out E 2.7K 100K 0.68uF 1 2 3 820 100K V1-B 330 uF 6 7 8 VOL 2 (dark) 1M LOG VOL 1 (bright) 1M LOG .0022uF .022uF 470K 270pF 470K 470pF 47K 1M D 820 100K V2-A 0.68uF 1 2 3 6 7 8 D 100K 250K LIN TREBLE 470pF .022uF .022uF 33K 1M LOG BASS 25K LIN MID NOTE 3 Revision 11 from AX84.COM Redrawn by Steve Luckey Completed on February 18, 2007 NOVEMBER PROJECT NOTE 1NOTE 2 If the amp is too bright at lower settings of volume 1, remove this cap, or substitute a lower value. If the amp is too bright in general at all volume levels, remove this cap or substitute a lower value. For a cleaner tone with less distortion, remove this cap. Negative Feedback scaling resistor value is determined by the Output Transformer tap used: 2.5 tap = 22K 4 tap = 29K 8 tap = 39K 16 tap = 56K NOTE 1 NOTE 2 NOTE 3 NOTE 4 EL84 max plate dissapation is 12 Watts. Set BIAS ADJ in Fixed mode to provide 8.4 Watts (70% max). Measure mV between BIAS and COM test points and directly convert to mA. Measure Plate voltage. (Plate voltage) X (mA) = plate dissapation. 12AX7 V1-A 12AX7 V2-B E POWER STANDBY Blue components mounted on cap cans Red components mounted on terminal strip OK to use EZ81 收音机爱好者资料库 Ra d i o Fa n s .CN T S G NFB 1N4007 V5V4 V3 V2 V1 B+ node C B+ node D Ground #2 AC Bias Input Ground #1 B+ node B Ground #3 Ground #4 BIAS Fixed Cathode 270p 470p 470p V6 Board Dimensions:11 1/2 x 2 3/4 Designed by:Steve Luckey Date:February 01, 2007 November Project Board Layout 1K ohm 5 watt 150 ohm 5 watt 1K ohm 5 watt + + 250F 50V + + 25F 150V + + 25F 150V .022F 630v .022F 630v .1F 630v .022F 630v .022F 630v .022F 630v 0.68F 100v + + 47F 450V + + 330F 25V 0.68F 100v .022F 630v .0022F 630v 10K Bias 1 / 2W1 / 2W Presence 5K-L Master 1M-A Bass 1M-A Midrange 1M-A Treble 250K-L Bright 1M-A Normal 1M-A 0.1F 250v 收音机爱好者资料库 Ra d i o Fa n s .CN