This is not the issue actually. The issue is that the dac on the receiving end has a limited SNR budget for it's whole amplitude range, and windows can't tell it to switch gain modes or anything like that. So when you reduce the volume digitally, you are just sending the dac samples that are scaled to the lower register of voltages that it can put out. This hurts the SNR because you reduce the signal but not the baseline noise the dac makes. Using a pot on an amp completely sidesteps this issue by allowing the dac to work at its optimal output level while making the volume lower as desired.
Bolivian_Spy t1_iy2lx9b wrote
Reply to comment by G65434-2_II in The just the right amount of smoothness and resistance by UnnecessaryMovements
This is not the issue actually. The issue is that the dac on the receiving end has a limited SNR budget for it's whole amplitude range, and windows can't tell it to switch gain modes or anything like that. So when you reduce the volume digitally, you are just sending the dac samples that are scaled to the lower register of voltages that it can put out. This hurts the SNR because you reduce the signal but not the baseline noise the dac makes. Using a pot on an amp completely sidesteps this issue by allowing the dac to work at its optimal output level while making the volume lower as desired.