Electronics Overview
Speaker Output Section
Now we can take a look at the speaker output section circuitry which is essentially kept separate in layout from the headphone output section. The front channels use a separate circuit with a PCM 1796 DAC on the front channels and a CS4362 multi-channel DAC for the remaining channels.
PCM 1796 Digital to Analog Converter (DAC)
This DAC is used in the same was as we see in the headphone output section and as seen on Essence Series soundcards. The chip offers a dynamic range of 123dB and a THD+N rating of 0.0005%. This DAC chip is a Current (I) output part so it requires a differential current to Voltage converter section.
CS4362 Digital to Analog Converter (DAC)
This chip is used for rear, side and center/subwoofer channels. The unit offers 24 bit at 192 KHz with an 114db Dynamic Range and a -100db THD+N rating. The chip also offers low clock jitter sensitivity
Opamps
NE5532
The 5532 opamp is probably the best known audio opamp and does offer a great deal in the way of price to performance. While it is true some of their specs may be lacking in comparison to todays flagship opamps, the 5532 has literally been used in every type of audio component you can think of from Pro studio mixers, to high end receivers and amplifiers. Chances are a good percentage of your music was also piped through some 5532s at some point during its mixing and mastering. Even though they are a cheaper product, they do offer some quality sound with a more gritty tubish edge.
JRC2114D Opamps
These opamps are used in the front speaker output section as a Differential Current (I) to Voltage (V) converter section. The chip has a slew rate of 15V/µs typ. And a low noise 0.9µVrms.
LM4562
These are becoming more and more common on modern soundcards because of their excellent sound quality and amazing specifications. In this circuit the chip is used as a final buffer for the front channel speaker Output.
CS5381 Analog to Digital Converter (ADC)
This Cirrus Logic chip seems to be a staple on ASUS soundcard designs and for good reason as it is a fairly high quality Analog to Digital Converter chip that gives the user 120dB of dynamic range and a THD+N rating of -110dB. This chip is built using a differential architecture which provides excellent noise rejection for the input signal.
