MODULE HISTORY
Since its introduction in 1986, the PB-1 has gone through a number of updates and revisions. Over the course of its history some of these changes have resulted in upgrading to newer modules. What follows is a historical breakdown of PB-1 modules. It should also be noted that the 460CSL was introduced in 1992 and therefor modules obsoleted before that time were never used in the CSL version.
OUTPUT MODULES:
Q42647-0
Original Output Module. No longer available. Q42717-1
Output Module: 12 resistor small predriver. Last out- put module for PB-2 for use with TO-220 package driver transistors.
Q42871-6
TO-3P Driver Output Module. Not for use in THC units, not retrofittable into TO-220 driver transistor units. Q42966-4
TO-3P Driver #2 Output Module. Not for use in THC units, not retrofittable into TO-220 driver transistor units. May replace this or Q42871-6 only.
Q43015-9
THC Output Module with TO-3P drivers. Not retrofittable to any older units. Does not require special main module for THC ODEP recompensation. Also im- proved bias stability.
Q43203-1
THC #2 Output Module. Replaces Q42967-2 only. Electrically identical, but larger screw head plates prevent shorting which could occur with the first THC output module.
MAIN MODULES:
Q42665-2
Original Main Module for PB-2. No longer available. Q42683-5
Main #2 for PB-2. No longer available.
Q42818-7
Third Gain Main Module. Same circuit board as the universal PC board used in MT-600/1200, MA-600/ 1200, and PB-1 (Q42776-7), except that PB-2 re- quired some unique component values. Added third gain stage and ground lift switch. Can replace all older modules. Note that if this module is being used to replace an older module, you may have to slide the ground lift switch to the left (ground lift position) and clip off the plastic switch protrusion in order for the module to properly fit in the unit.
Q43059-7
THC Main Module built on D 7993-5 circuit board. On this module the boost circuit has been deleted, the third position (1.4V) is added to the Sensitivity Switch, and additional fault circuitry has been added to the module. Although it is possible to modify any older unit to accept this module, it is recommended that the Q42818-7 be used to replace main modules in all older units, and this module be used only as a replacement for itself.
