USTARS AUDIO BD93 DAC Module

The Ustars Audio BD93 is a DIY DAC module based on a dual AK4493SEQ architecture, designed for high-resolution digital-to-analogue conversion. It supports streams up to 32-bit 768kHz as well as DSD512, relying on a dual-mono topology to isolate each channel and limit crosstalk, resulting in more stable reproduction and improved retrieval of fine detail.

This approach extends to the integration of a dedicated MCU controller, enabling precise exploitation of the converters' capabilities while providing access to advanced settings such as multiple digital filters and DSD NOS mode, allowing the conversion behaviour to be adapted according to listening preferences or system constraints.

Ustars Audio BD93: Dual AK4493SEQ DAC

The use of two AK4493SEQ chips, each dedicated to a single channel, ensures effective channel separation, reducing interference and enabling cleaner, more detailed reproduction. This architecture promotes a balanced output with coherent tonal continuity, while the internal processing ensures fast and accurate conversion, contributing to a sense of transparency and fluidity.

Beyond conversion itself, advanced digital filter management — including multiple roll-off profiles and a low-dispersion mode — allows the impulse response and bandwidth to be adjusted, providing a practical means of optimisation depending on the content and the associated signal chain.

Ustars Audio BD93: I2S Interface

The BD93 relies on an I2S interface compatible with Amanero USB modules, enabling direct ribbon cable integration without additional adaptation, while compatibility with digital cards in interconnect mode extends control and synchronisation possibilities. This modularity allows a complete system to be built by combining power supply, digital interface and control, while maintaining a scalable architecture.

Ustars Audio BD93: Output Stages and Power Supply

The module provides dual analogue outputs with a level of 2.1Vrms on RCA and 4.2Vrms on XLR, relying on a balanced topology to ensure broad compatibility with preamplifiers and amplifiers, while maintaining a signal level suited to Hi-Fi standards.

The split power supply — +5V for the digital section and ±12 to ±15V for the analogue stage — isolates the critical stages, helping to reduce interference and stabilise overall operation.