Essence STX II delivers industry-leading 124dB SNR audio clarity, a much-envied quality inherited from the revolutionary and widely-acclaimed Essence STX sound card - and up to 64 times better than typical onboard audio hardware. Headphone output reaches a fantastic 120dB SNR. A high-precision clock is crucial to audiophiles. Integrated circuits are susceptible to heat and temperature changes, which is why Essence STX II includes a premium temperature-compensated crystal oscillator (TCXO) clock source. It is an ultra-accurate timing technology that ensures ultra-low jitter.