This post is about sharing my experience for the present of DC offset at the output of a DAC, especially when we build it by our own, we want to make sure it is safe to the equipment after it. Since the DAC is considerably the top-chain in the audio system, so it is important to look this issue in the first place.
DC offset is a nightmare, especially when the equipment after the DAC such as preamp or the power amplifier is not using any capacitor or transformers in the signal path to blocking the DC present at the input. Just a small amount of DC, let's say 100 mV at the input of an amplifier will multiple by the gain from the amplifier, plus its current, will harm to the speaker's driver. In most cases, it will burn the driver's coil.
DC is inaudible, but it moves the driver cone. It creating the heat to the woofer driver coils and burn it. It is safe for the tweeter since the capacitor included in the cross-over network inside the speakers will protect it, act as DC blocking to the driver.
This post will explore the vintage multibit DAC that naturally have DC offset at the analog output and how to solve these problems.
