One of the criticisms/weaknesses of the group here is extreme bias that any sort of detectable difference in electronics is chalked up to poor controls or poor test conditions.
There was a whole thread where someone heard the difference between disc and file playback and the OP was criticized needlessly when reviewing the user manual pointed out that disc playback utilizes an upsampling/remastering algorithm and file playback via USB did not get upsampled.
We should be trying to figure out what possible scenarios could lead to these differences to be heard.
Here, if we look at the OP’s amplifier, it’s got a pretty low input impedance.
If the system uses capacitors for DC protection, and if the WiiM Ultra is going to the unbalanced TRS jack with only 4.7 kOhm of input impedance, that could lead to bass roll off compared to the D90 III which is running true balanced…
There was a whole thread where someone heard the difference between disc and file playback and the OP was criticized needlessly when reviewing the user manual pointed out that disc playback utilizes an upsampling/remastering algorithm and file playback via USB did not get upsampled.
We should be trying to figure out what possible scenarios could lead to these differences to be heard.
Here, if we look at the OP’s amplifier, it’s got a pretty low input impedance.
If the system uses capacitors for DC protection, and if the WiiM Ultra is going to the unbalanced TRS jack with only 4.7 kOhm of input impedance, that could lead to bass roll off compared to the D90 III which is running true balanced…