The UPC-HB has two output choices available: “FILTER ONLY” or “FILTER AND HUMBUSTER”.
Choose FILTER ONLY if you want to run equipment with the benefits of filtered AC. examples would be analog sources and digital sources, analog sources might be a preamplifier, phono stage or analog power amplifier. digital sources might be a CD player or a D to A converter. Choose FILTER AND HUMBUSTER if you want to lower or eliminate hum inside a unit, sensitive to DC on the line. examples might be a noisy power amplifier.