Class A output bd. ( BA283 type )

[maxwall]

Class A output circuit board - connections and components. Might be useful for Class A self rollers.


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Pads -DIY board..........................................Neve BA Schem
U0 - Input signal (-) ............................................ U
XF - Tx Primary....................................................... M Primary input
XF* - Tx primary ....................................................G or B, Primary Input
24 - +24vdc
G - ground
IN - signal input (+) ..............................................L ( BA283 Schem )

Components

DIY Board...................................................Neve BA schem (below)
Q1 - 2N3055 ..............................................................TR3 - 2N3055
Q2 - BC560C...............................................................TR2 BC560C (1C, 2B, 3E)
Q3 - BC560C ..............................................................TR1- BC560C (1C,2B,3E)

C4 -100uf/25 ..............................................................C6 - 100uf/25
C5 - 100uf/25v...........................................................C7 - 100uf/25
C7 - 100uf/25.............................................................C4 - 100uf/25
C8 - 10uf/25................................................................C1 - 10uf/25
C9 - 220pf....................................................................C2 - 220pf
C11 - 330pf.................................................................C5 - 330pf
C10 - 4700pf...............................................................C3 - 4700pf
C13 - 100uf/25.............................................80uf/25v, Gain Boost Cap

R3 1k2..........................................................................R4 1k2
R4 - 2k2.......................................................................R1 - 2k2
R5 - 68k.......................................................................R3 - 68k
R6 - 3k3.......................................................................R5 - 3k3
R7 - 56k.......................................................................R2 - 56k
R8 - 18k.......................................................................R6 - 18k
R9 - ? .............................................................Gain boost resistor
R10 - 47r 1w................................................................R7 (TR6) - 47r
R11 - ? ..........................................................Gain boost resistor ( F - E )
R2 - 5k trimmer.......................................................RV1 - 4k7 trimmer