Cerrot - Almarg is correct. Packetization has no bearing on the jitter in networked or USB systems. Both are buffered and master clock established in the device interface.
The older Adaptive technology relied on the computer clock, so it was deficient is this way. IT could only be improved with local PLL's which are no match for a free-running clock.
Likewise, DACs that have master clocks that are synchronized to an incoming stream are no match for a free-running clock. Jitter will be higher.
Buffering of the data and "pull" protocol combined with a free-running master clock with low jitter is simply the best way to achieve the lowest jitter in digital. See these plots to realize how low it can be:
http://www.audiocircle.com/index.php?topic=116570.0
The plots at the bottom approach the lower limit of jitter using current affordable technology. Most of the jitter is in the 15-18 psec range. You will not find a transport this low.
Steve N.
Empirical Audio
The older Adaptive technology relied on the computer clock, so it was deficient is this way. IT could only be improved with local PLL's which are no match for a free-running clock.
Likewise, DACs that have master clocks that are synchronized to an incoming stream are no match for a free-running clock. Jitter will be higher.
Buffering of the data and "pull" protocol combined with a free-running master clock with low jitter is simply the best way to achieve the lowest jitter in digital. See these plots to realize how low it can be:
http://www.audiocircle.com/index.php?topic=116570.0
The plots at the bottom approach the lower limit of jitter using current affordable technology. Most of the jitter is in the 15-18 psec range. You will not find a transport this low.
Steve N.
Empirical Audio