@seigen please read page 14 of the Vivaldi DAC manual, -10dB is dCS’ highest recommended level for direct connection
https://www.dcsltd.co.uk/wp-content/uploads/2015/06/Vivaldi-DAC-Manual-v2_0x.pdf
https://www.dcsltd.co.uk/wp-content/uploads/2015/06/Vivaldi-DAC-Manual-v2_0x.pdf