Description: 
USB receiver chip: SA9027
SA9027 is a high performance audio stream processors, USB full speed compatible. Focus on the SA9027 also supports asynchronous mode, so the local clock to reduce the output jitter,: DSD2PCM play; support for Apple feedback mode (Apple comes with drivers, no need to install) it contains a set of stereo playback and recording channels and a set of IEC60958 S / PDIF transceiver channel. SA9027 is an ideal choice for stereo digital audio interface applications. Its resolution and sample rate can be configured separately for the 16/24 bit and 32 / 44.1 / 48 / 88.2 / 96KHz.

DAC decoder chip: ES9023
ESS's ES9023 is a 24bit stereo audio digital-analog converter chip (DAC), and the king's ES9018 chip with a door, integrated chip 2Vrms output driver amplifier. Uses the industry's advanced digital SABRE - analog conversion technology, the chip set the best sound quality, cost-effective in one, making it ideal for digital to analog conversion. Can be used in Blu-ray player, CD / DVD, HD set-top boxes, digital TV or audio receiver equipment and other products. 
ES9023 internal use patented ultra stream (Hyperstream) architecture and time-domain jitter elimination technology, making it possible to achieve record levels of jitter-free sound quality, dynamic range up to 112dB. 
Because the chip integrates a charge pump can generate a negative voltage, ES9023 can refer directly to the output ground 2Vrms, eliminating the coupling capacitor DC voltage isolation in a single power supply. Moreover, the output amplitude according to actual needs, set by the resistance less than 2Vrms level. Noise can also switch to full suppression. Dedicated control / status pin allows the microcontroller to control in the absence of circumstances easily integrated into the system.

Headphone amplifier chip: MAX9722
MAXIM (Maxim) MAX9722 stereo headphone amplifier is limited board space for portable devices Design.
MAX9722 uses a unique, patented DirectDrive architecture, in order to produce a single supply Ground-referenced output, eliminates the need for large-capacity DC-blocking capacitors, saving board space and component Height. 
Integrated noise suppression circuitry, a comprehensive noise suppression circuit during startup and shutdown process can be inhibited clicks

Sound and crackling. 
Low-power shutdown mode reduces supply current to 0.1μA. 
Each channel can be provided to a 16 ohm load or 32 ohm load power 70mW or 130mW power, and only 0.009% THD + N. 
217kHZ frequency with 80dB power supply rejection ratio (PSRR), so the device can work in a noisy few under the word power, no power linear regulator.

A. Power Indicator 
B. Computer USB port 
C. Headphone output interface 
D. Lines and fiber output interface 
E. Volume switch controller

Features:
Upgrade your computer sound choice.
Supports ASIO, WASAPI and other drivers. 
MINI PC USB decoder (external sound card). 
Using asynchronous audio transmission technology approved. 
The direct supply After the computer purification, very easy to use. 
Ultra-small size (thickness, width, like with the iphone 4), easy to carry.
Along with line output, optical signal output and headphone amplifier output.

Parameters:
Sampling rate: 32 ~ 96KHz (including 88.2KHz) 
Bit width: 16 ~ 24Bit 
USB transmission specifications: USB2.0, asynchronous audio transmission 
THD + N: DAC <0.003% amp <.005% 
Frequency response: 10Hz ~ 48KHz 
Impedance adaptation: 8Ω ~ 600Ω 
Maximum output power: 130mW + 130mW / 32Ω 
Dynamic range: 110dB (24Bit) 
SNR: DAC> 105dB amp> 100dB 
Output amplitude: 2Vrms 
Power consumption: <0.5W 
Size: 87 X 58.5 X 9.6mm
Warranty: 1 year