Bose AV28 Manual page 19

A hardware issue was found with the CS4224 codecs whereby audio passing through its A/D
converter emerges with left/right sample pairs mismatched; specifically, with left samples lagging
right samples by one sample clock. In other words, left/right sample pairs coming out of the ADC
together were not sampled together (right was sampled before left). The codec's DAC section has
the reverse problem: left samples will emerge ahead of the associated right samples. The net result
of this hardware bug is that audio passed fully through the codec (from ADC input to DAC output)
will have no improper left/right delays. However, audio passed only partially through the codec
(only the ADC section, for example) will have left/right pairs emerge slightly out of phase. This
slight phase difference will have no noticeable effect when played through conventional stereo
speakers; however, slight spatial anomalies might be noticed if played through a surround-sound
system.
Source Playing Zone 1
S/PDIF
Network
Output
(Used for
Cobalt II)
Internal DVD Disc Left/Right
O.K.
Internal CD-DA Left/Right
O.K.
Internal MP3 Disc Left/Right
O.K.
Right
Internal AM/FM
Leads Left
External S/PDIF Left/Right
O.K.
Sources
Right
External Analog
Leads Left
Sources
When playing-back an audio stream which was recorded using pre-emphasis (common in earlier
CD's, for example), the media center's analog Record Outputs will not properly apply de-emphasis,
as follows. The resulting audio will have more treble than desired:
Playing-Back Pre-Emphasized Audio Streams
Source Playing Zone 1
S/PDIF
Network
Output
(Used for
Cobalt II)
Internal CD-DA O.K.
O.K.
External S/PDIF
Sources
Theory of Operation
CS4224 Hardware Bug: Effect on Postman Console Audio Outputs
Zone 1 Analog
Variable
Record
Analog Output
Output
(Used for
Cobalt I)
Left/Right Right
O.K. Leads Left
Left/Right Right
O.K. Leads Left
Left/Right Right
O.K. Leads Left
Left/Right Right
O.K. Leads Left
Right
Left/Right
O.K. Leads Left
Left/Right Right
O.K. Leads Left
Zone 1 Analog
Variable Record
Analog Output
Output
(Used for
Cobalt I)
O.K. De-
Emphasis
is Missing
O.K. De-
Emphasis
is Missing
19
S/PDIF Headphone
Record Output
Output
Left/Right Left/Right
O.K. O.K.
Left/Right Left/Right
O.K. O.K.
Left/Right Left/Right
O.K. O.K.
Right Left/Right
Leads Left O.K.
Left/Right Left/Right
O.K. O.K.
Right Left/Right
Leads Left O.K.
S/PDIF Headpho
Record ne
Output Output
O.K. O.K.
O.K. O.K.
Zone 2
Zone 2
S/PDIF Variable
Network Analog
Output Output
(Used for
(Used for
Cobalt II) Cobalt I)
Left/Right Left/Right
O.K. O.K.
Left/Right Left/Right
O.K. O.K.
Left/Right Left/Right
O.K. O.K.
Right Left/Right
Leads Left O.K.
Left/Right Left/Right
O.K. O.K.
Right Left/Right
Leads Left O.K.
Zone 2 Zone 2
S/PDIF Variable
Network Analog
Output Output
(Used for (Used for
Cobalt II) Cobalt I)
O.K. O.K.
O.K. O.K.