1.3 Volume and Tone Adjusting Circuits
Adjusts master volume and treble and bass tone of input signals.
1.4 Power Amplification and Protection Circuits
Amplifies input signals' power to drive speakers to produce sound; Protects circuits of speakers
and power amplifier automatically in abnormal conditions.
1.5 Microphone Circuit
Adjusts volume and tone of signals from the microphone and superimpose them on left and right
channels after echo processing.
1.6 Main Board Control and Display Circuits
Receives control commands and send control signals to achieve control function. Drives the VFD
screen to show the current working mode.
1 Circuit Makeup
This unit's circuit can be divided into six parts.
1.1 Source Circuit
Supplies power to each circuit unit.
1.2 Input Circuit
Selects one of four lines of input analog signals and sends it to the rear circuit.
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9 The Explanation For Key Components
IC Sc6931P
VDD
XIN
XOUT
D1/REQ
D2/SCK
D3/DATA
D4/IDSW
TEST
SLEEP
D-GND
A-GND
LPF2 OUT
L PF2 IN
OP2 OUT
OP2 IN
CC2
LPF1 IN
LPF1 OUT
OP1 OUT
OP1 IN
REF
CC1
VCC
EASY/ U-COM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
