"Does having a asynchronous USB help with jitter and obviate the need for reclocking or SPDIF converters, as claimed here?"
It does eliminate some sources of jitter, namely the computer clock, however jitter can still be introduced by common-mode noise and RFI. The master clock and the associated clocking circuitry in the interface is also critical to getting a good result. The design will determine whether Async USB interface is good or not. There are a lot of mediocre ones out there.
Steve N.
Empirical Audio
It does eliminate some sources of jitter, namely the computer clock, however jitter can still be introduced by common-mode noise and RFI. The master clock and the associated clocking circuitry in the interface is also critical to getting a good result. The design will determine whether Async USB interface is good or not. There are a lot of mediocre ones out there.
Steve N.
Empirical Audio