The DAC chip in the E203, the ESS ES9039SPRO, was developed under the latest Hyperstream® IV architecture.

The ES9039SPRO features an 8-channel independent current output path. To align with this design, Cayin have implemented a corresponding 8-channel independent I/V (Current-to-Voltage) conversion circuit. It is followed by the LPF circuit to extract four fully-differential signals, which are then paired with a Buffer driver circuit. Both the LPF and Buffer circuits are designed with a fully symmetric and balanced architecture, ensuring that the signal is transmitted and amplified in a balanced manner throughout the E203.

The amplification circuit of the E203 features a Hybrid design, seamlessly integrating high-performance OPA1612 op-amps with carefully selected discrete bipolar junction transistors (BJTs). This approach combines the precision and efficiency of op-amps with the superior sound quality and flexibility of discrete components in amplification stage.

The OPA1612 provides excellent performance, while the discrete BJTs enable a fully symmetric current amplification stage. The discrete BJTs allows for extensive sound tuning, giving Cayin the freedom to shape the desired tonal characteristics to make ES9039SPRO more emotionally engaging on E203, and forming the foundation for true Class A amplification.

E203 features a dual mode Class A/AB amplification mode, and enhanced Hyper mode for highest power output performance. E203 does not feature a line out circuit.