b3pre-a 电路图.pdf

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1、Date: April 20, 1995 Sheet 1 of 1 Size Document NumberREV B- - -1.0 Title PREAMPLIFIER TYPE AO-28 MODEL B3, C3, RT3 G C23 .033 EF TO VOLUME TABLET C24 82PF C22 24-90PF C17 680PF RADIO-PHONO EXPRESSION CONTROL C16 .033 C6 30PF C15 51PF C2 39PF R9 820K R4 1.8M R5 10M A C3 100PF R6 47K R3 270K NON-VIB

2、CHANNEL INPUT 5 1 62 7 V1 6AU6A R8 470K C5 .01 R10 3.9M 130V R27 1.8M R29 330K +1.7 (V2) 2 1 3 V4A 12AX7A 145V +280 C18 220PF C20 220PF R30 1.8M R32 1.8M R31 68K R33 68K 60PF/SEC R35 3.3M +1.7V (V2) 7 6 8 V4B 12AX7A R34 15M 140V +280 R37 270K R39 330K R38 390K R36 330K 7 6 8 V3B 12BH7A C26 30/25R42

3、1200 +290 R41 100K 12V R40 .3M TONE G BN T3 CABINET TO TONE +205 335V C25 .001 R97 4500 TO HTRS T7 BL C19 .0022 C21 .001 C35 150PF D INPUT FROM VIBRATO SCANNER C OUTPUT TO VIBRATO LINE C13 1.0 R7 2.2M +280 +1.7 (V2) C7 24PF C11 .0047 C4 .33 INPUT FROM MATCHING XFMRS THRU VIBRATO TABLETS R13 4.7M B C

4、8 100PF VIBRATO CHANNEL INPUT R14 10M R16 47K R12 270K R18 10M C12 .0047 5 1 62 7 V2 6AU6A R15 2.7M +290 2 1 3 V3A 12BH7A R25 100 R63 390K C33 .0033 C34 .001 C33 .0022 R63 390K R62 220K C34 .001 R62 100KC32 390PF C35 390PF GY 117VAC 60 HZ 375V R91 900 C56 40/450 7 3 4 1 6 V8 6X4 +280 +290 C60 50/300

5、 R95 4.7K R96 4.7K R94 4.7K +37 +33 R99 180 R98 7500 R100 2.7K R101 2.7K T5 C57 40/400 C58 30/350 C56 10/350 TOP VIEW THESE COMPONENTS GO BETWEEN POINTS P AND D IN AO-28-1 LETTER ONLY) INSTEAD OF AMPLIFIERS (WITH NO CODE THOSE SHOWN AT LEFTR24 22K R22 820 95V C10 .33 R20 2.2M R19 470K R17 1.2K +280

6、R23 22K R21 1M C9 30/25 +1.7V R48 470K R47 47K 6 7 1 V5 6C4 T5 C28 .047 R53 47K R52 47K * * (* SEE NOTE) C32 .0082 T6 R61 39K P 2 1 3 V7A 12AU7A CHANNEL BALANCE SELECT FOR (MOUNTED ON P TERMINAL) V8 C56 C57 C58 T1 V1V4 V3 EXPRES- SION CONTROL T3 C9,C26 C59,C60 V5V6V2V7 T4 T6 NKMJHECPDABLGY BL BNGGF

7、N +33 R60 30K PERCUSSION CUTOFF +205 R58 4.7M 7 6 8 V7B 12AU7A 6 7 1 V6 6C4 C31 .33 R54 47K +37* +205 C29 100PF C30 25/25 R49 2.2K H PERCUSSION CHANNEL INPUT T4 TO PERCUSSION SWITCH R50 22 R51 4.7K K J R55 82K 25V +33 R56 22K R57 1.5M L M TO PERCUSSSION SWITCH NOTE: R52,R53,R54,C32 IN AO-28-1 AMPLIFIERS (WITH NO CODE LETTER ONLY) SIDE VIEW RadioFans.CN 收音机爱 好者资料库