Sony DAV-FX500 Operating Instructions Manual page 99

You call set the following items with AMP MENU on the remote.
AMP menu
DIMMER _DIMMER ON
LDIMMER OFF
DEMO --]-DEMOON
L DEMO OFF
ATTENUATE'' _ATT ON
LATT OFF
* "ATTENUATE" may not appear depending on die selected lkmclion.
ggus