Thank you! I have corrected this typo. I meant pre-amplifier.
Thank you very much for the information! Do I understand correctly that we are talking about improving SINAD using the PRE-90, which is the most effective of all these "volume controls"?
Thank you again!
Okay. I've never seen a THD sweep graph for the D90SE.
The graph in post-1208326 is a comparison measurement of SINAD when the volume is adjusted before the D90SE and when the volume is adjusted after the D90SE.
The settings for the D90SE are as written in the graph.
The connections are as follows:
AP => TOSLINK => D90SE => XLR 2m => Volume control device => XLR 2m => AP (200kohm)
AP => TOSLINK => D90SE => XLR 2m => XLR 2m => AP (200kohm)
About the measurement of the D90SE in "PRE mode".
A, The volume of the input signal is fixed at 0dBFS, and the volume is adjusted inside the "PRE mode D90SE". (Front panel or remote control)
B, The volume of the input signal is variable, and the D90SE is in "DAC mode"
In preliminary measurements, the SINAD of A and B was within the measurement error range. Therefore, we only plotted "B", where automatic sweep measurement by AP is possible.