Sony HDCAM HDW-F900R Maintenance Manual page 78

FP CPU (IC816: flash RAM) on the FP-152 board carries out
audio control according to the audio mode information
received from SS CPU (IC1) on the SS-92G board.
The IFA-19G board has a front microphone amp (10dB/
20dB/30dB) gain switch circuit.
The APR-59AG board is composed of monitor amps (IC106,
IC109, etc).
The AL-43 board is composed of final amps (IC101, IC201)
and connects to the CNB-23 board. The CH1 and CH2
output signals are output from the 5-pin connector (CN301)
on the AXM-33 board.
The AXM-33 board is composed of LINE-IN/AES/EBU-IN/
MIC-IN switch (S101, S201), microphone amp (20dB/30dB)
gain switch circuit and AES/EBU digital audio signal
receiver block (IC500). The LINE IN input level settings can
be switched between +4dBu, 0dBu, and _3dBu with the
slide switch (S202) on the AXM-33 board.
The SW-1309 board is the ON/OFF switch (S1, S2) for +48
V.
After turning the power to the unit on, FP CPU (IC816) on
the FP-152 board, each port is initialized, and the PLL circuit
lock information for TG (IC321) on the DVP-41 board from
SS CPU (IC1) on the SS-92G board is received. Then, reset
for audio control IC (IC404) on the FP-152 board is released,
program download and register data settings are performed,
and then MUTE is released. (EE sound can be monitored)
Front microphone signal passes through the MA-103 board,
IFA-19G board, and MB-1096 board before entering the
input signal selector (IC5 to IC8) of the FP-152 board.
Rear input signal passes through the AXM-33 board, CNB-
23 board, and MB-1096 board before entering the input
signal selector (IC5 to IC8) of the FP-152 board.
While switching LINE SELECT (IC16), FP CPU (IC816) on
the FP-152 reads the 2-bit signal for each switch (S1 to S4).
With this information, the board switches between FRONT/
REAR/WIRELESS switch information received by the input
signal selectors (IC5 to IC8) and selects the audio signal.
The CH1 or CH2 signal selected by the input signal selector
(IC5, IC6) on the FP-152 board is input into the differential
amp (IC1: switches between balanced/unbalanced). The
signal then passes through the 9dB attenuated circuit. Then
the signal is input into the A/D balance/unbalance conversion
amp (IC101, IC104), and after being increased about 1dB, is
input into the A/D converter IC (IC103: 24-bit).
At the same time, the CH3 or CH4 signal selected by the
input signal selector (IC7, IC8) on the FP-152 board is input
into the differential amp (IC2: switches between balanced/
unbalanced). The signal then passes through the 9dB attenu-
ated circuit. Then the signal is input into the A/D balance/
unbalance conversion amp (IC302, IC304), and after being
increased about 1dB, is input into the A/D converter IC
(IC301: 24-bit).
1-68
The serial digital audio signal input from the AES/EBU
INPUT connector passes the receiver block on the AXM-33
board, and is decoded in the decoder (IC200) on the FP-152
board.
Then the sampling rate conversion in synchronous with the
recorded video signal takes place in the sampling rate
converter (IC201, IC202).
The 24-bit (64fs) 2CH digital audio signal from each A/D
converter output, each decoded 2CH digital audio signal
from AES/EBU input that underwent sampling rate conver-
sion, and the digital audio signal from the CA adapter are all
input to the FPGA (IC401) on the FP-152 board. Then the
signals are switched and converted into 128fs serial 4CH.
The front volume and side volume are connected to the A/D
terminal of FP CPU (IC816) on the FP-152 board. The
volume voltage is digitalized with a built-in 10-bit A/D, and
after changing the DSP multiplier, sends the signal to audio
DSP (IC404) on the FP-152 board. After digital conversion,
the combination of front volume and side volume, go through
multiplication processing in FP CPU (IC816) and are sent to
the audio DSP (IC404) for the FP-152 board.
The digital audio signal made into 128fs serial 4CH with
FPGA (IC401) on the FP-152 board is input into audio DSP
(IC404). There, the signal undergoes processes from the
audio DSP high-speed calculation, such as gain processing
during manual control, AGC processing, LIMITER process-
ing, LPF-ON when using the front microphone, recording
EMPHASIS processing, headroom level switch, delay
processing for internal SG and VIDEO/AUDIO phase
matching, and audio level detection. Then, the signal is made
into 64fs parallel (CH1&CH2, CH3&CH4) with FPGA
(IC401) on the FP-152 board. It then passes through the MB-
1096 board before being input into the DVP-41 board.
The D/A parallel signal (64fs) for playback passes through
DVP-41 board and MB-1096 board. Then the signal is made
into 128fs serial with FPGA (IC401) on the FP-152 board
and is input into audio DSP (IC404). The signal goes through
processes such as playback DE-EMPHASIS processing,
headroom level switch, and output LIMITER processing.
Then, the signal is made 64fs parallel in FPGA (IC401) on
the FP-152 board while CH1&CH2 and CH3&CH4 are
selected. The FPGA (IC401) output playback digital audio
signal is then input into the 24-bit D/A converter (IC521).
The D/A converter output passes through the differential amp
(IC504, IC505), the T-shaped twin filter, the ATT unbalance/
balance conversion amp (IC514, IC517), MB-1096 board,
CNB-23 board, final amp (IC101, IC201) on the AL-43
board. Then the signal is output from the 5-pin XLR connec-
tor on the AXM-33 board. The audio signal for the monitor
undergoes volume control in the APR-59AG board, then
passes through the amp (IC106) on the APR-59AG board
before being output.
HDW-F900R/V1 (E)