Bose AV28 Manual page 17

The AV28 Signal Routing and Clocking Diagram, which follows, shows the fully-detailed audio
path, including clocking information. The legend at the bottom identifies which signals are analog,
which are digital, and what the relevant clock rates/sources are.
AV28 AUDIO PATH:
Signal Routing and Clocking
ANALOG
L/R
SOURCES
U201
TEA6422
ANALOG
TV EXT
1 MUX
VCR EXT
2
AUX EXT
3
TAPE EXT
4
TUNER
5
DVD MIXDOWN
6
U503
CS4340
DAC
D/A
Port must always
run at 44.1kHz
sample rate
(clocked by U303).
(CONFIGURED AS I2S)
DVD ROM
ATAPI
XFACE
S/PDIF
SOURCES
J501
OPTICAL EXT
OPTICAL
S/PDIF
RCVR
Theory of Operation
1
2
3
U502
74HC157
MUX
AC-97 PORT
U1
U1
I2S
CS98K
D0
AUDIO
(LS500C)
PORT D1
DVD
DECODER
D2
D3
IN
Port supports many sample
rates (but D0-D3 and IN
always share the same rate).
ZONE 1 OUT
U501
ZONE 2 OUT
0
CS8415
S/PDIF
AUX EXT
1
MUX
AND
2
RCVR
TAPE EXT
3
OUT
VCR EXT
4
TV EXT
5
6
U303
CS4224
CODEC
VOLUME
A/D D/A
CELL
U302
74HC157
MUX
U304
74HC157
MUX
U403
CS4224
CODEC
VOLUME
A/D
D/A
CELL
U402
74HC157
MUX
U404
74HC157
MUX
U505
74HC157
MUX
ANALOG L/R
2
I S: U303 PROVIDES CLOCK (ALWAYS 44.1 kSPS)
2
I S: U1 OR U501 PROVIDES CLOCK (SOURCE DEPENDENT)
2
I S: U303, U1 OR U501 PROVIDES CLOCK
S/PDIF: UP TO 96 kSPS
17
ANALOG
HEADPHONE
U205
OUTPUT
NJM4556
BUFFER
ZONE 1
ANALOG
L/R
VARIABLE
OUTPUT
U202
ANALOG
CS4340
L/R
DAC
RECORD
OUTPUT
D/A
U306
ZONE 1
CS8405
S/PDIF
S/PDIF
DIGITAL
XMTR
OUTPUT
ZONE 2
ANALOG
L/R
VARIABLE
OUTPUT
U406
ZONE 2
CS8405
S/PDIF
S/PDIF
DIGITAL
XMTR
OUTPUT
S/PDIF
RECORD
OUTPUT
OPTICAL
J701
S/PDIF
RECORD
OPTICAL
OUTPUT
S/PDIF
DRIVER