SMSL SU-8 being harsh and bright balanced

[Cortlendt]

I have SMSL SU-8 (paired with THX AA 789 AMP) and it is a nice feature packed DAC. However, no matter what settings for sound/filter are being used, with balanced setup it sounds harsh and bright for some frequencies. Best set up is using Rich 2/Brickwall sound color and filter combination, but still it is peaky. It is less of a problem when usage is in unbalanced mode.

I'm thinking about upgrading to Topping E50 or SMSL DO100, but will this bright harshness of the sound persist due to similar DAC chip being used?

 

[Soundstage]

What are you comparing to and what is your headphone?

 

[Cortlendt]

For sources I have additionally Aune X1S combo and Lg G7 smartphone. For headphones I have AudioQuest NightOwl, ZMF Atticus and Campfire Cascade.

Problem most often manifests in male voices sounding harsh and peaky.