PRO USB is a passive DI box specially designed for mobile devices. It is compatible with Windows, Mac OSX, iOS and Android systems. It does not require any drivers to achieve plug and play. It can be used as a signal impedance matcher for mobile devices and built-in headphone amplifier and volume control.

PRO USB is the first to use TYPE-C as the terminal to connect to mobile phone and computer.

The USB audio decoder combines Com True CT-7601SR and Cirrus Logic CS-43131 to achieve 192KHz/32bit performance, and are compatible with DSD digital formats and all common lossless and compressed music formats.

The PRO USB has a pair of built-in UNiKA-PROTM EI30A10E 1+1:1+1 isolation transformers. The transformer has a special copper foil layer and a dedicated grounding layer, which can ensure the high signal/noise ratio and dynamic sound of the device, and avoid unnecessary Leakage caused by radio frequency interference, grounding interference and potential difference. PRO USB is especially suitable for mobile phone, computer and media player. It converts high-impedance signals into low-impedance balanced signals, which is convenient for extending the wiring distance and blocking interference.

PRO USB has built-in mini TRS headphone monitor output and monitor volume control, which can drive 16Ω~600Ω headphones.



If you need to use the ASIO driver to play DSD stream files in WINDOWS 10, or connect PRO USB it the WINDOWS 7 system, please download the driver from the official website:

File name: UNiKA ASIO_DSD_driver_ENG_20201208

MacOSX no need to install ASIO driver either play normal music format or DSD.

When PRO USB is successfully connected to the computer, UNiKA USB DEVICE will be displayed in the sound card option, because the computer has automatically defaulted PRO USB as its external sound card. If it is not automatically recognized, you can open the settings to change it.

If the connection is successful, the “SOURCE ACTIVE blue light on the top cover of the PRO USB will also light up”, indicating that it has been powered by the computer.


For Android OS, Use the TYPE-C to TYPE-C or Micro USB to TYPE-C data cable to connect the phone and PRO USB, then you can connect and play. After the connection is successful, the blue “SOURCE ACTIVE” light on the cover will also light up.

For iOS, Limited by Apple’s special transmission encryption method, some models may not be able to directly connect to PRO USB via TYPE-C USB for playback. It is recommended to purchase Apple’s original lightning or TYPE-C OTG dongle for connection.


• Built-in UNiKA-PROTM EI30A10E isolation transformer for each channel
• Built-in CT7601 USB bridge and CS43131 DAC with headphone amplifier
• 32bit convert rate and 192KHz over sampling
• Compatible with Windows, Mac OS, iOS and Android systems.
• Compatible with DSD digital formats and all common lossless and compressed music formats.
• Mini TRS jack used to connect earphone or headphone with volume control
• Built-in Type-C USB digital audio input connector
• The output is equipped with a GND/LIFT switch

Circuit principle Passive/Transformer balance output
USB Version & connector Ver 2.0 Type- C
UAC bridge solution 32bit/192KHz
DAC solution 32bit/192KHz with 2x DSD
Power supply Powered by PC or mobile phone throuth Type-C
playback connector with LED status indicator
Music beat indicator LED
Output connector 2 x Male XLR through ISO Transformer
Output GND/LIFT switch Shared push button
Max Output level 0.778Vrms
Headphone power output 30mW per channel into 32Ω
5mW per channel into 600Ω
Frequency response 20Hz-20KHz, ±0.5dB
S/N ratio @20Hz~20KHz un-weight >110dB
T.H.D. @1KHz 0dBV output <0.005%
Transformer Ratio 1:1+1:1
Chassis 1.6mm/1.2mm steel cabinet and chassis
Surface finished Durable complex painting
Dimension (W x D x H) 78 x 124 x 46 mm
Weight 0.64Kg
Shipping weight 0.67kg
Packing per carton 20pcs/14.00Kgs
Shipping dimension per carton 305 x 283 x 195mm