Surround Circuit; Input Balance Circuit - Toshiba CN27E90 Technical Training Manual

6. SURROUND CIRCUIT

The surround circuit used in this model has the modes shown
in Table 15-2 of the modes, description will be given for 5
mode. The description will be made according to items
shown below.
Surround Mode Assumed sound field Front Rear
CONCERT HALL Concert hall
THEATER Movie theater
NIGHT CLUB Disco, Night club
STADIUM Baseball stadium
Dolby Surround Dolby surround soft
OFF Off
Table 15-2
A/V SW
O O
O O
O O
O O
X O
X X
L OUT +
CD04
1m50V
RD23
15K
CD05
RD24
56K
22m
4V
R OUT
CD06
1m 50V
Input balance control

7. INPUT BALANCE CIRCUIT

Fig. 15-8 shows the input balance circuit.
The input balance circuit is to adjust gain of Lch and Rch so
that (L-R) component in the matrix circuit becomes zero.
Adjustment by the input balance volume control on the
remote hand unit.
[dB]
L c h
0
Response
-8
M i n
QD08
2
L
4
6
8
10
12
R
14
Fig. 15-8
116
C e n t e r
C o n t r o l
Fig. 15-7
+9V
1
Leh
3
Input buffer
CD09
5
22m 16V
7
9
11
Reh
13
Input buffer
R c h