New, 2017 model - ATDAC-8AM
Added the separate phone amplifier (OPA1622) with analogue volume control (pot.)
USB Powered 384kHz/24bit PCM and DSD-256
Galvanic Isolated Audio DAC
Based on XMOS and Asahi KASEI New Generation Premium "VERITA" AK4490/AK4493 chip.
Only high quality components used, from the world known companies and reliable suppliers: Xmos, AKM, Silicon Labs, Texas Instrument, Analog Devices, Elna, Nichicon, Murata. Panasonic 0.1% thin film resistors in analogue circuit.
Up to 384kHz PCM sample rate.
Up to x256 DSD sample rate.
USB Audio Class II Operation:
not required drivers for MacOS, Linux, Android.
required driver for Windows
Full galvanic isolation from USB source (PC, Tablet, etc.)
Additional 3.5mm jack output for headphones *.
Size (case): 100x75x30mm.
No need external power supply in most applications **.
For special applications, external power supply input with reverse polarity protection provided ***.
* - Phone output is additional, for high quality sound use RCA with external head amplifier. If use Phone output don't forget to enable the digital volume control in your player (8A only! Not required for 8AM/8AX).
** - Using with cellular phone or tablet will quickly discharge it's battery, so using external power supply is recommended. Also if you want to use very long (>1.5m) USB cable.
ATDAC-8A power consumption is about 0.55A, which is a little bit more then the regular USB port provides according to the standard. But I never seen USB port, not satisfied ATDAC-8A with it's current, at least with the short (<0.5m) USB cable.
However, it is better to use USB cable as short as possible. Also do not use very thin USB cables ("Chinese no-name").
*** - External power supply requirements: 5VDC (+0.5, -0.2V), 0.6A at least.
Pay attention - internal pin in the DC connector is "minus".
Reminder - ATDAC-8A output is primary dedicated to amplifier connection. If you want to use headphones, use external high quality headamp. Due to a lack of power which can be consumed from USB, DAC's Phone Output sounds good just at the low volume.
ATDAC-8AM has better performance at headphone output, but as the power is limited - no way to use low impedance (16 Ohm) headphones! Also with high impedance (600 Ohm) headphones and low sensitivity, there may be a lack of volume.
There is no problem with most 32-250 Ohm headphones.
A new, ATDAC-8AX model is ready. AK4493 instead of AK4490. That's all.
Q. What is the difference, from the various Chinese DACs from AliExpress, Taobao and EBay?
1) Very good sound quality!
2) Powered from USB (with optional external 5VDC power)
3) GALVANIC ISOLATION from PC USB.
4) This is not Chinese product.