5-30 www.hp.com Technical Reference Guide
Input/Output Interfaces
5.8 Audio Subsystem
These systems use the HD audio controller of the 82801 component to access and control a
Realtek ALC260 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 5-11. 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 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.
Figure 5-11. Audio Subsystem Functional Block Diagram
82801 ICH
HD Audio
Interface
Headphone
Aux Audio In
Mic In
Line In
Audio (L/R)
Header
Audio In (L/R)
HD Audio
Codec
ALC260
Speaker
Audio (L+R)
Header
Header
Line Audio (L/R)
Rear Panel
NOTES:
L/R = Separate left and right channels (stereo). L+R = Combined left and right channels (mono).
P23
P6
P11 [2]
Audio
Amp
HD Audio I/F
Front Panel
Mic In [1]
Headphones
Out
Mic Audio (L/R)
[1] CMT only
PC Beep
Header
P23
[2] SSF, ST, MT, and CMT only. On USDT form facter, aux audio is routed through MultiBay interface.
Out (L/R)
Line Audio
Line Out
Mic Audio (L/R)