The output stage of any DAC can have a large influence on its sound quality. The output stage must translate the signals generated by the D/A circuit into signals compatible with connected amplifiers.

This process is ideally without much signal loss, coloration, contamination or degradation. Most D/A circuits have feeble outputs, which must be amplified or buffered in order to successfully navigate the outside world.

This amplification or buffering usually results in at least some degradation of sound quality, as the signal is recreated by the active circuitry. This explains why there are thousands of driver circuits to choose from; each one has a different weakness.