Hifime UH1-Digital manual


Thanks for buying the Hifime UH1-Digital! This is the UH1 without the DAC. It is used to get a optical, coax or I2S/DSD signal from USB or to send a an optical, I2S/DSD signal to USB. 

The UH1-Digital has the following specs:

  • Inputs: USB, i2S/DSD over HDMI), optical
  • Outputs: USB, i2S/DSD over HDMI), optical, coax
  • Outputs are ground isolated from USB
  • Asynchronous USB transfer with two TCXO as master clock
  • Savitech SA9227 USB receiver (no DAC chip)
  • Accepts all sample rates up to 384kHz/32bit (max 192 for optical)
  • No drivers required for Mac and Linux. Drivers available for Windows
  • USB powered
  • Switchable USB modes (Full Speed / High speed). Full speed does not required Windows drivers
  • Dimensions: 85x70x24mm

Some important notes:

  • The optical, I2s/DSD inputs routes the output to USB/computer only! It doesn’t convert i2s to the COAX/SPDIF outputs
  • The HDMI input/output is not compatible with “normal” HDMI devices


The UH1 is plug in play in Mac and Linux. Windows requires drivers to be installed prior to usage.

Mac OS X

With a Mac you might be running already, here is a guide on how to select the Hifime DAC as the output device:

See the guide for selecting the device as the output.


See this guide for installing Windows drivers.

See the guide for selecting the device as the output.


The inputs will show up in input devices when active. Make sure to set the sample rate to the same rate as you send from the source. Also make sure to set the project sample rate in the recording program to the same as you are sending. If the sample rates are not set to the same then you will get noises and clicks.

HDMI interface (input(output)

The HDMI signal is LVDS (Low Voltage Differential Signal) level, it is a balanced signal which is better than single ended TTL, especially for longer distances. it uses a driver chip and can’t be directly connected to TTL inputs/outputs.

Here is a linked drawing with the pinout for DSD and I2s.

The I2S input works in slave mode (using MCLK from the source).

High Speed / Full Speed switch

The UH1-Digital has a switch to set USB Full Speed (12Mbps) or High Speed (480Mbps) mode. High Speed mode is needed by sample rates above 24/96 but requires drivers in Windows. If you set the switch to “Full Speed” mode it will run in USB Audio class 1 which means that you don’t have to install drivers in Windows. This feature can be convenient in some situations. On some versions “L” represents FS, and H represents High Speed.

Hope you’ll enjoy the UH1-Digital! And please consider spreading the word and write a review.