HiFime UH1 384kHz USB DAC, headphone amplifier and I2S/DSD interface

Introduction  The HiFime UH1 It is based on the Savitech SA9227 asynchronous USB receiver clocked by two TCXO oscillators, PCM5102 dac chip and TPA6120 headphone amplifier. Sound The HiFime Digital to analog converter (DAC) sounds detailed and ultra clear with a huge sound stage. The two outputs are able to drive a wide range of headphones or can be connected to an amplifier. One output features a built in headphone amplifier while the other output is the direct output from the DAC chip. The direct output can also be used with many headphones and sounds very relaxed and open. The headphone output provides more punch and intensity. Which one you prefer will depend on the device you connect to the DAC. Two quality TCXO are used as the master clock to control the timing. This asynchronous USB transfer mode will give the DAC 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. Additional features The UH1 also has several digital outputs which makes this device also a high resolution quality asynchronous USB to I2S, DSD, SPDIF and optical converter. It also has optical INPUT which will redirect the optical signal to USB/computer. Note: The SPDIF/OPTICAL input does not go to ANALOG output! SPECIFICATIONS Inputs: USB INPUT: Asynchronous USB transfer with two TCXO as master clock USB receiver Savitech SA9227 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 INPUT: To USB/computer only! It does not do optical to analog audio! Support samples rates up to 192kHz and 16/24/32 bit. Outputs: ANALOG OUTPUTS: There are two analogue outputs, both are on the front of the dac. The line out is direct from the PCM5102 dac chip and the headphone output is buffered with the TPA6120 headphone amplifier. The TPA6120 is a high fidelity headphone amplifier from Texas Instruments. The PCM5120 is a ground centred design meaning that it doesn’t need any DC blocking capacitors on the output. Capacitors in the signal chain will always color the sound, so it will always be better to avoid capacitors in the signal chain. The analog outputs PCM only (not DSD as it’s not supported by PCM5120) Line output: 2.1Vrms Headphone output: 80mW/1.6Vrms max output to 32ohm load. 16mWrms/2Vrms to 250ohm loads Headphone minium load : 16 ohm For high impedance headphone, you can also use the line output which offers a higher signal on high impedances. 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 on the front of the unit, uses same output as headphone output. It supports up to 192kHz sample rates and 16,24,32 bit. Summary:  Digital to analogue chip: Texas Instruments PCM5102 Headphone amplifier: TPA6120 USB receiver chip: Savitech SA9227 USB transfer mode: Asynchronous (clocked with 2 x TCXO) Analogue outputs: Line out and headphone output (PCM only, DSD not supported) Digital outputs: I2S, DSD, SPDIF/optical Digital inputs: SPDIF (routed to USB only) Samples rates supported: 32, 44.1, 48, 88.2, 96, 176.4, 192, 352.8 and 384kHz Bit rates: 16, 24 and 32 bits Drivers: Not required for MAC/Linux. Required for windows for sample rates above 96/24.  New driver supports Win 10 here. Size: 85x70x24mm