mark@mips.COM (Mark G. Johnson) (04/09/88)
! ##########################################################################
! The famous "Holman Phono Preamplifier"
! Advent Corporation, August 6, 1976
!
! (designed by Tomlinson Holman, later of APT/Holman)
!
! Node 1 = phono cartridge input, node 0 = system ground,
! node 40 = phono stage output (to volume control, etc).
!
! Power Supplies & local decoupling
Vplus 80 0 15.0 ! Volts
Vneg 90 0 -15.0
R81 80 81 10.0 ! Ohms
R91 90 91 10.0
C81 81 0 10U ! (micro)Farads
C91 91 0 10U
!
! Input loading network including selectable capacitance
R1 1 0 100K ! (kilo)Ohms
C1 1 0 50P ! (pico)Farads, adj. 0->300
C2 1 2 1.0U ! (micro)Farads
R2 2 0 91K
! differential pair with resistor in emitter "tail"
Q2 C=10 B=2 E=3 NPN TYPE=TIS97 ! Noise selected, from T.I.
Q4 C=81 B=4 E=3 NPN TYPE=TIS97 ! beta = 400 to 800
R3 3 91 100K
! Current source load
Q10 C=10 B=12 E=11 PNP TYPE=2N5087 ! Motorola PNP
R12a 81 12 1.2K
R12b 12 0 15K
R11 81 11 6.8K
!
! Second stage: Darlington PNP transistor with resistor load
Q21 C=20 B=10 E=21 PNP TYPE=MPSA65 ! Motorola PNP
R21 21 81 150
R20 20 91 1.5K
! RIAA feedback network
R22a 20 22 100K
R22b 22 4 1.2M ! (mega)Ohms
C22a 20 22 750P ! (pico)Farads
C22b 22 4 2700P
R23 4 23 1.8K
C23 23 0 5.6U
!
! Third stage: emitter follower and infrasonic filter
R33 20 33 220
C32a 33 32 0.1U
C32b 32 31 0.1U
R32 32 30 43K
R31a 81 31 390K
R31b 91 31 430K
Q30 C=81 B=31 E=30 NPN TYPE=TIS97
! output coupling
R41 30 41 220
C41 41 40 10.0U
R40 40 0 100K
!
!
! that's all
--
-Mark Johnson *** DISCLAIMER: Any opinions above are personal. ***
UUCP: {decvax,ucbvax,ihnp4}!decwrl!mips!mark TEL: 408-991-0208
US mail: MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086