Originally Posted by scorch123
Did you work on this project?
Yes, I know the hardware inside and out.
Can you explain the three separate jitter specs?
Not completely, in the confines of this little text box, but i'll give it a shot
Jitter, like any kind of noise, accumulates at each component or wire, so it is instructive to report it at a few key points in the system. When manufacturers talk about jitter it is not always clear where and how it was measured, or if they just pulled a number out of the sky. Our measurements are taken using a high speed scope and specialized software, looking directly at the clock or spdif signals. This gives a very high level of precision and the ability to see minute relative differences during the process of designing incremental improvements in board layout and such. It would be hard to describe everything with a single number, so the three points indicated are:
Oscillator: this is the IC and crystal which generate the clock signal to begin with.
DAC: this is right at the clock input pin on the internal DAC, after the signal has traversed through one other IC and a few inches across the PCB.
S/PDIF receiver: this at the end of a cable connected to the intrumentn with a 75 ohm terminator, and indicates what an external s/pdif receiver would "see".
Are the digital inputs auto-sensing?
If you mean in terms of which one to use, no, they are individually selected as separate inputs.