Block Diagram - Sony WRR-801A Service Manual

Outline
The WRR-801A consists of the following boards and tuner unit:
Board name
MB-761 board
CN-1510 board
Tuner Unit (WRU-801A)
The tuner unit consists of the RF board and the DP board.
Tuner unit works as a PLL synthesizer diversity tuner, and its power voltage (DC +9 V) is supplied from the CN-1510
board through the MB-761 board.
The RF (radio frequency) signals are input from both antenna A and antenna B, and the audio signal is output to the MB-
761 board through the CN-1510 board. The RF board is composed of RF block, audio block, CPU block and voltage
regulator.
The DP board is composed of display block and the operation block.
Power Supply Block
The switching regulator generates DC± 9 V and they are supplied to the MB-761 board. Generated DC± 9 V are used for
the audio output amplifiers inside the MB-761 board. Generated +9 V is supplied to the tuner unit, too.
Audio Block
The audio signal (AF) output from each tuner unit (WRU-801A) are input to the MB-761 board through the CN-1510
board. Signals are then output from the output connectors (J1001 to J1501) in line levels after passing through the filter
amplifiers (IC1001 to IC1501), output amplifiers (IC1001 to IC1501) and audio muting circuits (Q1001 to Q1504). The
audio signals from each tuner unit are input to the mixer (IC1601), then output from the MIX output connector (J1601).
MB-761 Board
The RF signal input block and audio signal output block are mounted on this board. This board consists of the RF signal
distributor/attenuator circuit, audio output circuit and audio signal muting circuit.
CN-1510 Board
This board functions as a relay board for power voltages, RF signals and audio signals between the tuner unit and MB-761
board.
WRR-801A
WRU-801A
SECTION 5

BLOCK DIAGRAM

Ref. No.
1000 to 1900 series
110, 1000, 1900 series
5-1