This question has a three part answer since the digital signal path through a SymNet system has three different major components.

Converter delay: Approximately 850 microseconds for the AD, and 624 microseconds for the DA.
One DSP core: Maximum delay through any given 8×8 DSP core is approximately 240 microseconds, though typically it will be much lower. The max delay through the DSP core of an 8in or 8out is 120 microseconds.

SymLink: Approximately 80 microseconds for an audio signal to travel, via SymLink, from the DSP core of one 8×8 to the unit immediately downstream. If there are any units in between, add an additional 80 microseconds for each SymNet DSP, 20 microseconds for each CobraLink and 20 microseconds for each BreakIn12 and BreakOut12.

In summary: The typical delay for a signal that goes into an analog input on an 8×8, and exits from an analog output on the same 8×8 is usually around 1.5 milliseconds.