Compaq W4000 Manual De Usuario

Chapter 5  Input/Output Interfaces 

 

 
The systems covered in this guide come configured with one of two types of audio support: 
 
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Desktop/configurable minitower audio subsystem 
Small form factor audio subsystem 

 

 
A block diagram of the audio subsystem is shown in Figure 5-11. These systems use the AC’97 
Audio Controller of the 82801 ICH2 component to access and control an Analog Devices 
AD1885 Audio Codec, which provides the analog-to-digital (ADC) and digital-to-analog (DAC) 
conversions as well as the mixing functions.  All control functions such as volume, audio source 
selection, and sampling rate are controlled through software over the PCI bus through the AC97 
Audio Controller of the 82801 ICH2. Control data and digital audio streams (record and playback) 
are transferred between the Audio Controller and the Audio Codec over the AC97 Link Bus.  
 
Desktop and Configurable Minitower systems implement Business Audio, which has the codec 
stereo analog output applied through a headphone jack(s) and switch logic to a mono 3-watt 
amplifier that drives a 16-ohm speaker. The switch logic allows a system with two headphone 
jacks equal functionality between jacks.  
 
Small Form Factor systems feature Premier Sound, which includes a 6-level equalizer that 
compensates for chassis acoustics and a low-distortion 8-watt amplifier driving a speaker.   
 
The analog interfaces allowing connection to external audio devices include: 

 

Mic In - This input uses a three-conductor (stereo) mini-jack that is specifically designed for  
connection of a condenser microphone with an impedance of 10-K ohms. This is the default 
recording input after a system reset. On desktops and CMTs, if the front panel assembly is 
installed then either microphone 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 (10k-ohm) 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 16-ohm (nom.) stereo headphones or powered speakers. Plugging into the 
Headphones jack mutes the signal to the internal speaker and, on SFF systems, the Line Out jack 
as well. On desktops and CMTs, if the front panel assembly is installed then either headphone 
jack is available for use (but not simultaneously).  

 

Line Out (SFF only) - This output uses a three-conductor (stereo) mini-jack for connecting left 
and right channel line-level signals (20-K ohm impedance). A typical connection would be to a 
tape recorder’s Line In (Record In) jacks, an amplifier’s Line In jacks, or to powered speakers that 
contain amplifiers. Plugging into the Line Out mutes the internal speaker.  
 
 

5-26   Compaq Evo and Workstation Personal Computers 
          Featuring the Intel Pentium 4 Processor