McIntosh MA6500 Service Manual page 6

BLOCK DIAGRAM
PG
LEFT PG
INDICATOR
INDICATOR
DRIVER
TO PRE AMP
OUT (INT) POWER AMP
PRE AMP LEFT
INPUT
(INT)
PRE AMP IN SWITCH
(EXT)
TO MICRO CONTROLLOR
PRE AMP IN
POWER AMP
PRE AMP RIGHT (EXT)
INPUT
(INT)
TO PRE AMP SWITCH
OUT (INT)
RIGHT PG PG
INDICATOR DRIVER
7
CASCODE
POWER DIFF
VOLTAGE
GUARD AMP
AMP
CURRENT
SOURCE
ELECTRONIC
ATTENUATOR
CASCODE
DIFF
VOLTAGE
AMP
AMP
CASCODE
DIFF
VOLTAGE
AMP
AMP
ELECTRONIC
ATTENUATOR
CURRENT
SOURCE
CASCODE
POWER DIFF
VOLTAGE
GUARD AMP
AMP
POSITIVE
CURRENT
LIMITER
+ + +
PREDRIVER DRIVER OUTPUT
DC
BIAS
- - -
PREDRIVER DRIVER OUTPUT
NEGATIVE
CURRENT
LIMITER
NEGATIVE
FEEDBACK
NEGATIVE
FEEDBACK
NEGATIVE
CURRENT
LIMITER
- - -
PREDRIVER DRIVER OUTPUT
DC
BIAS
+ + +
PREDRIVER DRIVER OUTPUT
POSITIVE
CURRENT
LIMITER
VOLTAGE DC LEFT
RECTIFIER
LOG AMP METER
AMP
TURN ON
DELAY
VOLTAGE DC RIGHT
RECTIFIER
LOG AMP METER
AMP
8
LEFT
OUTPUT
SPEAKER 1
SPEAKER
SWITCHING
SPEAKER 2
THERMAL
PROTECTION
RIGHT
OUTPUT
SPEAKER 1
SPEAKER
SWITCHING
SPEAKER 2