Audio Signal Processing - Hitachi 36SDX88B Service Manual

13. Audio Signal Processinq
1 Audio Signal Select
The audio L and R signals from tuner Ul 01, the AV 1 L and R signals, the AV 2 t and R signals, and the AV 3
L and R signals are switched by IYOI (CXA1545AS) on the NTSC PWB. The L-s and R-s are the output signals
which are sent to the Audio Control IC 1401 (TDA7318D) and the monitor output jacks. 1401 consists of IIC bus
controlled amplifiers per channel. These serve to control Volume, and Tone (Bass I Treble). The L and R signals
from IYOl and the PC L and R signals are switched by 1401 (TDA7318D) on Audio PWB. The L-s and R-s are
the output signals which are sent to the SRS Surround IC 1403.
2
SRS Surround
1403 (SRS5250AS) is the SRS surround processor. SRS ON I OFF is controlled by 1402 (HD140539).
3
BBE
1404 (NJM2t50AD) is BBE sound enhancement processor. BBE ON / OFF is controlled by IIC bus from 1001.
SDA
Antenna -+
I
UIOI
Tuner
I
r
1
AV2
CXAI 545AS
AV Switch
AV3
L/R
L/R
1003
- M62393AP
.
DAC
I
;cL
4 4
Mode
1402
HDl40536
OnlOff
SRS mode
switch
Mode
L/R
A , lY
1
1401
L/R
__+ TDA7318D
//
//
b Audio control
L/R
PC
1
Monitor out
w
Hi-fi out
(Variable)
110