I think I've cured the sibilance related issue with ths dac. Although it didn't present as sibilance in my system I have experienced a slightly grainy and etched treble and reduced air, ambience and resolution.
The fix was a good quality mains filter - connected to a good quality mains cable. I used 2x ferrite toroids with about 20T on both active and neutral and then bypassed with a 100nF MKP. After doing this the resolution went into a new stratosphere. Sibilance is now very natural - although it is of course still present if on the recording.
The fix was a good quality mains filter - connected to a good quality mains cable. I used 2x ferrite toroids with about 20T on both active and neutral and then bypassed with a 100nF MKP. After doing this the resolution went into a new stratosphere. Sibilance is now very natural - although it is of course still present if on the recording.