The output level of PCM and DSD is pair matched at 2.2VRMS. The volume is digital and control the CS4398 DAC IC digital volume itself. The solution is 24bit.
When playing PCM and DSD, the DSD level is lower. Therefore, there is a problem when having DSD and PCM file within the same play list. For AMI MUSIK DS5, we have designed our product to have pair matching output.