Audio Subsystem - HP dx7300 Technical Reference Manual

5.8 Audio Subsystem

These systems use the HD audio controller of the 82801 component to access and control a
Realtek ALC262 HD Audio Codec, which provides 2-channel high definition analog-to-digital
(ADC) and digital-to-analog (DAC) conversions. A block diagram of the audio subsystem is
shown in Figure 5-10. All control functions such as volume, audio source selection, and
sampling rate are controlled through software through the HD Audio Interface of the 82801 ICH
component. Control data and digital audio streams (record and playback) are transferred between
the ICH and the Audio Codec over the HD Audio Interface. The codec's speaker output is
applied to a 1.5-watt amplifier that drives the internal speaker. A device plugged into the
Headphone jack or the line input jack is sensed by the system, which will inhibit the Speaker
Audio signal.
Theses systems provide the following analog interfaces for external audio devices:
Mic In—This input uses a three-conductor mini-jack that accepts a stereo microphone. This is
the default recording input after a system reset. On MT/CMT systems with both front and rear
microphone jacks, either jack is available for use (but not simultaneously).
Line In—This input uses a three-conductor (stereo) mini-jack that is specifically designed for
connection of a high-impedance audio source such as a tape deck.
Headphones Out—This input uses a three-conductor (stereo) mini-jack that is designed for
connecting a set of 32-ohm (nom.) stereo headphones. Plugging into the Headphones jack mutes
the signal to the internal speaker and the Line Out jack as well.
Line Out—This output uses a three-conductor (stereo) mini-jack for connecting left and right
channel line-level signals. Typical connections include a tape recorder's Line In (Record In)
jacks, an amplifier's Line In jacks, or to powered speakers that contain amplifiers.
Line In
Front Panel
Mic In
Rear Panel
Mic In [1]
Header
P11 [2]
Aux Audio In
NOTES:
L/R = Separate left and right channels (stereo). L+R = Combined left and right channels (mono).
[1] MT/CMT only
[2] SSF, ST, MT, and CMT only.
Figure 5-10. Audio Subsystem Functional Block Diagram
Technical Reference Guide
PC Beep
82801 ICH
HD Audio I/F
HD Audio
Interface
Line Audio (L/R)
Header
P23
Mic Audio (L/R)
ALC262
HD Audio
Mic Audio (L/R)
Codec
Audio In (L/R)
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Header
P6
Speaker
Audio
Audio (mono)
Amp
Header
P23
Headphone
Audio (L/R)
Headphones
Out
Line Audio
Out (L/R)
Line Out
Input/Output Interfaces
5-27