SMSL unveils the DO400, a powerful, high-quality DAC/headphone amplifier. It incorporates quality components such as the latest ESS ES9039MSPro chip, an XMOS XU316 USB interface, 11 OPA 1612A and the latest generation Qualcomm QCC5125 Bluetooth chip. To complete the package, an MQA decoder is integrated into the DO400, enabling it to decode high-resolution audio streams up to PCM 32bit 768kHz, DSD512 and MQA-CD. Headphone amplifier performance is also very good, thanks to the use of a PLFC circuit. The DO400's complete and varied connectivity will adapt to a wide range of configurations and input sources. SMSL has opted for an internal symmetrical circuit design, and the exterior features a large screen and a number of small aesthetic details, making this a pleasing-looking device.

A high-performance headphone amplifier

On the front of the DO400 are three headphone outputs: a balanced 4-pin XLR headphone output, a balanced 4.4mm jack output and an unbalanced 6.35mm jack output. The headphone amplifier circuit is an ultra-low distortion 4-channel PLFC circuit. It delivers over 2W output power with less than 0.0001% distortion at less than 16 ohm load. The DO400 can therefore be adapted to all types of headphones, thanks to its varied connectivity and high output power; 2x 6000mW / 16Ω, 2x 3000mW / 32Ω, 2x 700mW / 300Ω and 2x 350mW / 600Ω.