Samsung DVD-R157 Service Manual page 108

Circuit Operating Descriptions
13-5-3 Amplifier (MM1692)
VIC1 of JACK PCB is 6dB amplifier.
Based on CVBS signal, the final output level must be 2Vpp without 75ohm terminal resistance.
Because the level of video encoder output is only 1Vpp, the level is adjusted with the special
amplifier.
When mute of pin 5 is high active, if the pin is floating and connect to power, the output
signal is never outputted.
Y, C, Y(R), Cb(B), Cr(R) outputted from video encoder are inputted to VIC1 [Pin14, 16, 13, 12,
11] respectively. And CVBS Output[Pin 15] is made by Y & C Mixing signal.
The signal to which gain is adjusted by amplifier is outputted from jack via 75ohm Resistance
(VDR1,2,4,5,6,).
13-12 Samsung Electronics