Don’t asynchronous USB inputs remove all jitter, resulting in bit perfect sound?
Asynchronous communication is defined as transmission of data without the use of an external clock signal. This allows data to be transmitted intermittently rather than in a steady stream. This also allows for variable bit rates and eliminates the need for the transmitter and receiver to have their clock generators synchronized.
Asynchronous digital communication is nothing new. It has been used for decades in obsolete protocols, such as RS-232C. Adopting it for USB audio inputs was one of several potential data transmission protocols and is far from what would be considered cutting edge technology.
As stated earlier, most computer communication is bidirectional and works with a system of checks and error correction. When the source sends a packet of data, the destination checks the packet and requests corrupted data packets to be resent. Since the asynchronous USB protocols used for most audio data is unidirectional, when an error occurs, no resend or error correction is possible.
The combination of asynchronous clocking and data buffering can remove jitter caused by packets of data arriving at irregular intervals, but it can’t correct corrupted data. Though asynchronous USB results in smoother and more analog-like sound, if it isn't bidirectional it has no error correction and can not assure uncorrupted bit perfect data.
Don’t batteries have the purest DC power?
There’s a common misconception that batteries have the purest DC power. Though batteries are better than the inexpensive wall wart type switching mode power supplies (SMPS) that come with many audio, video, and computer products, battery performance can’t compare to the performance of an ultralow-noise linear power supply.
Batteries use a chemical reaction to generate DC power, and each chemical reaction from each type of battery has its own audible noise signature. That’s why a specific type of battery, such as LIO4, sounds better than another type, such as SLA. In addition, the noise level of a battery changes significantly during different phases of the recharge cycle, making batteries an inconsistent-sounding power source. Of course, batteries also wear out and need replacing every year or three, which adds significantly to the cost of ownership.