Quality of power supply, proper heat sinking, quality/number of capacitors used, OS chop or no OS chip, quality of oversampling, quality of outputs, quality of chassis, filters used, presence/quality of tubes, how many volts it outputs, what kind of volume control, and so many other things all come together to make a ...

Do DACs actually sound different?

All DACs sound different when listening tests are done sighted and not level matched. There is nothing strange about that as the human brain is involved as 'test equipment'.

Does DAC affect sound quality?

There are three main types of DACs: standalone DACs, portable DACs, and DAC/headphone amplifier combinations. Standalone DACs: This type of Digital-to-Analog Converter is typically a simple box with inputs and outputs that you add to your existing signal chain.