I bought one of these and paired with my SMSL SU-9 via balanced XLR.
Sounds great, very clean and linear. makes everything a brighter and a bit clinical though, not brain piercing bright but just to the point you notice it getting sharp on the highs.
Randomly mine also died. red light on the front is fixed and no sound. it seemed me accidentally touching the connectors when swapping headphones triggered the protection circuit.
some improvements would be a digital protection circuit that switches back off when you restart as well as a manual to work out which gain is ‘low’ and ‘high’.