Dc Offset Voltage Adjustment - Marantz PM6005 Service Manual

DC OFFSET VOLTAGE ADJUSTMENT

Adjusting Procedure
DC Offset Voltage Adjustment
(1) Before turning on the power, Insert Digital Voltage Meter between the SPEAKERS SYSTEM A (L CH) "+" and "-".
Insert Digital Voltage Meter between the SPEAKERS SYSTEM A (R CH) "+" and "-".
(2) Adjust the VOLUME to MIN.
(3) Turn on the power. Then turn the SPAKERS SW to A.
Adjustment is started immediately after a speaker relay turns on.
(4) First L CH is adjusted.
The variable resistor V6003 on CUP12578Z is turned with adjustment driver, and the Digital Voltage Meter is adjusted
to "0 mV ± 3 mV".
(5) Then, R CH is adjusted.
The variable resistor V6004 on CUP12578Z is turned with adjustment driver, and the Digital Voltage Meter is adjusted
to "0 mV ± 3 mV".
NOTE : DC offset voltage drops when turn the semi-fixed resistor (V6003 and V6004) clockwise. DC offset voltage rises
when turn the semi-fixed resistor un-clockwise. Please turn it slowly, because value of Digital Voltage Meter
changes slowly.
(6) Although after-adjustment DC offset voltage has some change, Please check that the range of DC offset voltage
between L ch (R ch) "+" and L ch (R ch) "-" terminal of SPEAKERS SYSTEM A is "0 mV ± 20 mV". CHART OF
FACTORY MODE.
Digital Voltmeter
V
R ch
V6001
L ch
V6003 V6004
N6004
V6002
23
Digital Voltmeter
V