WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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WhitakerAudio
3.1.3 Amplifier PWB #2 (left)
The Amplifier PWB #2 (left) includes 25 quick-disconnect terminal posts and two 4-terminal
Molex connectors. The wire connection codes for this board are given in Table 3.3.
Table 3.3 Amplifier PWB #2 (left) Connection Wiring Codes
(Note that the color codes for the transformers listed in this table may vary. Consult device
documentation before proceeding.)
PWB Code Function Connection
Color Code Notes
Conn3 (4-terminal Molex connector)
GND Ground Shield Ground
INPUT Feedback circuit input to
amplifier White Connects to feedback R/C circuit on left
channel speaker terminal PWB
GND Ground NC
GND Ground NC
Conn4 (4-terminal Molex connector)
GND Ground Shield Ground
FB Audio input to amplifier White Connects to left channel volume control
GND Ground NC
GND Ground NC
The following terminals are quick-disconnect posts
GND GND Black Connects to GND terminal Rectifier PWB
BIAS Bias supply output Slate Connects to BIAS terminal Amplifier PWB #1
(right)
B+ +350 V dc B+ supply input Red Connects to B+ terminal on rectifier PWB
B+Sense B+ voltage source Red Output to B+Sense terminal on power
management PWB
-60V Bias input from rectifier PWB White Connects to -60V terminal on rectifier PWB
R55a Hum Balance control (R55)
high terminal Brown Connects to high terminal of R55
R55arm Hum Balance control (R55)
arm terminal Orange Connects to arm terminal of R55
R556b Hum Balance control (R55) low
terminal Green Connects to low terminal of R55
5VH2a 5 V heater winding from T51 Yellow From yellow lead of T51
5VH2b 5 V heater winding from T51 Yellow From yellow lead of T51
5VH2ct 5 V heater center-tap winding
from T51 Yellow/black From yellow/black lead of T51
5Vdc 5V dc source Yellow Connects to SW52 on the front panel
RYL51+ Voltage source to RYL51 coil White Connects to coil of RYL51
RYL51- Voltage source to RYL51 coil White Connects to coil of RYL51
GND Ground Black Connects to main chassis ground point