so here is at little info relating to a DAC with a tube output stage:
Dynamic range is the difference in volume between the quietest and the loudest passage, commonly measured in decibels (dB).
Since 1-bit = 6dB:
- 16-bit Red Book CDs have a dynamic range of over 96dB.
- 20-bit digital master tape has a dynamic range of over 120dB.
- 24-bit modern HD formats have a dynamic range of over 144dB.
DACs with tube output stages: the lowest noise floor on a tube output stage is about 90dB which means despite whatever the manufacturers may claim they can't even resolve a 16-bit recording.