Digital Audio Cables
USB Audio Cabel
Dual Head akku
With the "normal" audio USB cables, there is only one conductor strand. This strand contains the two data lines D+ and D-, the +5V supply voltage and the ground (0V).
With the Dual Head akku, everything is different.
The USB signal (Universal Serial Bus) is differential. The data is transmitted via D+ and D-. Thus, no ground connection between transmitter and receiver is necessary in a "domestic environment".
Shielding is superfluous for a balanced signal under normal conditions. However, if you operate an MRI next to the music system, it's a different story.
The cable has two USB-A plugs. One plug transmits the data. A battery pack is connected to the other, which provides the 5V voltage for the DAC. The battery is designed for a long charge cycle and only needs to be recharged every few months. A branded charger is included in the price.
AES/EBU Digital Audio Cable
Interestingly, sometimes not used, although the possibility would exist. AES/EBU is clearly better than S/PDIF ...
... because AES/EBU is differential. The characteristic impedance is set exactly to 110 ohms.
Is superfluous with a balanced signal under normal conditions.
With a balanced signal, a reference to ground is unnecessary. Therefore, this cable has no ground connection.