CD-C3H (serv.man6). Section 1 - Text - Sharp Audio Service Manual (repair manual). Page 15

– 15 –

1. Outline

The recent trend is toward rise of CD record level in the world, for example rock, dancing music, etc. In case of continuous high
level playback G-EQ (graphic equalizer) and VOL (Volume) are controlled (lowered) automatically after a lapse of specific time
(10 minutes) so as to get the easy-to-listen sound level.

2. Explanation of operation

The CD playback operation is explained below.

  

X

  : Threshold value of control circuit operation

  A  : Hight energy (hatched area) exceeding  

X

  is detecated, and the control mode is set.

  B  : After a lapse of 10 minutes the control is started.

Data is fetched every 4
seconds to control.

Initial frequency
characteristics.

Hand L frequency char-
acteristics are lowered.

VOL (Volume) is lowered.

At first, the  H and  L frequency characteristics are lowered as shown above so  thet the distortion
and disturbance are reduced. However, if hight energy exceeding  

X

  is detected, VOL is lowered

to get sound easy to listen.

Stable control
Continued control

The output data is fetched every  4 seconds  to  control. When quiet music is played back, the
control is performed so as to restore the initial frequency characteristics and initial VOL values.

Control mode cancel conditions

When output exceeding   

X

   is not given

continuously for 10 minutes.

When quiet music is played back.
When VOL is lowered.

When the power is turned off or on.

B  ~  C  :

C  ~  D  :

A

X

B

C

D

0w

10 minutes

Distortion clip point

SP output
level