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.

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

Bardzo fajny dac z asynchronicznym usb,wyjściem słuchawkowym,wyjsciem cyfrowym optycznym i liniowym.

W porównaniu z wyjściem słuchawkowym z komputera dźwięk dwie klasy lepszy.

Zero szumów , dźwięk nabiera dynamiki,detalów i przestrzeni.Naprawdę warto.

Znakomicie zgrywa się z koss porta pro.Dźwięk bajka.

Działał też z moim tabletem na androidzie 4.4 z usb audio player pro

W zestwie dac z oryginalnym pudełkiem i przewodem usb.W pełni sprawny.