Sony WRT-810A Operating Instructions Manual page 12

You can change the input attenuation setting in 3-dB steps in the range
of 0 to 21 dB.
Raise the setting to decrease the sound volume or lower it to increase
the sound volume, using the following procedure:
1 When the current channel selection is displayed (that is, when
the unit is in either channel set mode or channel display
mode), press the SET button to enter attenuation display/set
mode.
AF RE BATT
el Y
MAC
TVZATT CH
The current input attenuation setting in decibels will appear on
the display.
e Switching from channel set mode to attenuation display/set
mode
(Channel set mode) (Attenuation display/set mode)
3 - -
L taB
TVZATT CH
¢ Switching from channel display mode to attenuation display/
set mode
(Channel display mode) (Attenuation display/set mode)
ie Y ri (=) l Y
; oo Li (u => C ï dB
TV/ATT CH TV/ATT CH
The example shows TV channel display on the WRT-810A(88)
or WRT-820A(68).
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