ALIGNMENT PROCEDURE (C372)
I. INITIAL ADJUSTMENT (No load connected)
A. OUTPUT OFFSET VOLTAGE
1. Connect a DC Millivoltmeter between TP303 & TP304
(pin 1 of IC 301A & gnd),
then adjust VR303(50kohms) to get a reading as close as 0V as possible, +/-3V.
2. Connect a DC Millivoltmeter between TP403 & TP404
(pin 1 of IC 401A & gnd),
then adjust VR401(50kohms) to get a reading as close as 0V as possible, +/-3V.
B. IDLING CURRENT
1. Connect a DC Millivoltmeter to TP301 and TP302, then adjust VR302 (500ohms)
for 5-6mV reading on meter.
2. Connect a DC Millivoltmeter to TP401 and TP402, then adjust VR402 (500ohms)
for 5-6mV reading on meter.
3. Leave power “ON” for a minimum of 5 minutes.
C. ISC SENSITIVITY
Connect a DC Millivoltmeter to TP701 and TP702, then adjust VR701 (47kohms)
between –50mV to -100mV.
II. FINAL ADJUSTMENT
Repeat procedure A and B for offset voltage and idling current alignment respectively.
VR303 VR302
TP303 TP304 TP302 TP301
VR402 VR401
TP402
TP403 TP404
TP401
LEFT CHANNEL
RIGHT CHANNEL