Xonar Essence, the card has a PCI-Express x1 interface, requires additional power (see the MOLEX connector) and features gold plated inputs and outputs.
The high-end Essence is also equipped with an EMI shield and it brags with a SNR (signal to noise ratio) of 124dB
The high-end Essence is also equipped with an EMI shield and it brags with a SNR (signal to noise ratio) of 124dB

Photo courtesy of PC Watch.
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