HiFime UH1-Digital 384kHz USB to I2S/DSD/COAX interface (no DAC)

Introduction 

This is the UH1 without the DAC part. It is a pure high quality USB to i2s/DSD (over HDMI), COAX and OPT. This also has i2s/HDMI input (HDMI to USB)
It is based on the Savitech SA9227 asynchronous USB receiver clocked by two TCXO oscillators.

Two quality TCXO are used as the master clock to control the timing. This asynchronous USB transfer mode will give this device the responsibility to clock the data transfer instead of of your computer which has a clock of lesser quality with more noise and jitter introduced.

It accepts up to 384kHz sample rates and 16/24/32 bit. No drivers are necessary on MAC and linux computers! On Windows it can work without drivers up to 96kHz/24bit and with ASIO drivers up to 384/32. (Note that not all programs support ASIO). There is a switch that switches between Low and High sample rate mode. When set to Low, it works up to 96/24 with no drivers needed in Windows.

It utilises the USB port for power, so no external power supply is required. Also the outputs and inputs are ground isolated from USB.

Windows driver:
Download here (updated april 16th). New driver supports Win 10 here.

SPECIFICATIONS

Inputs:

USB INPUT:

• Asynchronous USB transfer with two TCXO as master clock
• USB receiver Savitech SA9227
• Inputs are ground isolated from USB
• Supported sample rates: 32, 44.1, 48, 88.2, 96, 176.4, 192, 352.8 and 384kHz
• Supported bitrates: 16, 24 and 32 bits
• Works in either Full speed or High Speed USB transfer mode selectable with a switch (“L” “H”). No drivers required in MAC/Linux in both full and high speed modes. Windows ASIO needs drivers for High Speed mode only.
• We are using two (expensive) TCXO to act as master clock.  45.1584MHz for 44.1, 88.2, 176.4, 352.8MHz sample rates, and  49.152MHz for 32,48, 96, 192, 384kHz sample rates. The USB transfer is clocked by the TCXO directly. This is better than PLL async mode and offers close to zero jitter. PLL async mode has ~30ps jitter, which is already quite low, but not as good as when clocked from TCXO directly.

SPDIF/OPTICAL/i2s(HDMI) INPUT:

• To USB/computer only! It doesn’t convert i2s to the COAX/SPDIF outputs.
• SPDIF Support samples rates up to 192kHz and 16/24/32 bit.

Outputs:

DIGITAL OUTPUTS:

• DSD/I2S using HDMI port. Here is a linked drawing with the pinout for DSD and I2s. Note – this it not compatible with “normal” HDMI devices. The HDMI port is only used as a convenient connector and a way to send i2s balanced which improves signal quality. The DSD signal is also balanced. The pinout is made so that there is no harm done if you should connect it to a normal HDMI device.
• Optical output
• Coaxial output​
• Outputs are ground isolated from USB

Size: 85x70x24mm

mod: ud227