14 DAY TRIAL // There is always some quality loss between the hardware that creates the sound, and the hardware that outputs the sound, that makes it heard to the human ear. The signal-to-noise ratio never went higher than 124 SNR, but ASUS has just launched two sound cards that reach that level.
The names of the products are Essence STX II and Essence STX II 7.1. They both are successors, of sorts, to the ASUS Essence STX (the first sound card with 124 dB SNR audio clarity and 600 ohm headphone amplifier).
Well, technically the two newcomers have only 120 dB SNR for headphone listening. Output is still at 124 dB SNR though.
As before, the headphone amplifier is of 600 ohm. ASUS has also added gain control for in-ear monitor (IEM) headphones, high-quality MUSES op-amps (operational amplifiers), low-dropout (LDO) regulators, and WIMA capacitors (for balanced sound), and swappable op-amp sockets.
The Essence STX II and Essence STX II 7.1 are more or less similar, with analog output, but the latter also has a daughterboard that lets it output 7.1 channel surround sound.
They should work just fine with high-quality headphones, powered analog speakers, or a Dolby Digital decoder.
ASUS implemented low-dropout (LDO) regulators and WIMA capacitors, for good sound balance, and a temperature-compensated crystal oscillator (TCXO) clock source (for precision). Sadly, prices were not in the announcement.