To switch between speakers and headphones as an active output on the Zen Dac 3, you can use the RCA or 4.4mm balanced outputs for speakers and the headphone outputs for headphones. The device features a Variable or Fixed output switch. In Variable mode, you can adjust the volume using the knob when connecting directly to active speakers via RCA or a 4.4mm to XLR cable. For headphones, simply plug them into the appropriate headphone jack. In Fixed mode, the output is set for connecting to a receiver or main amplifier without volume adjustment.
To physically switch between speakers and headphones, you would need to manually disconnect one and connect the other to the appropriate output. There is no automatic switching mechanism built into the device.
