“Nasal” Audio Note 3.1x Balanced.

I have an Audio Note 3.1x Balanced. This is the new type with 2x 12au7. I think this DAC sounds a “nasal”. I have had many other AN DAC’s before, and have mot noticed these colorations. I have tried to change the tubes to Telefunken ECC802s and Siemens CV4003 tipple micas with no luck. Does anyone have any idea what I can do? (Change to better resistors, capacitors etc..)??