Oppo PM-1 - Manual (Page 7)

5
Using Your Headphones
To a Headphone Amplifier,
AV Receiver or Other Mobile Device
To Left Ear cup
To Right Ear cup
Two headphone cables have been included with your OPPO PM-1.
The first cable terminates with a 6.35 mm connector and is
suitable for connecting the headphones to a headphone amplifier,
AV receiver, or integrated amplifier.
The second cable terminates with a 3.5 mm stereo plug and can be
used to connect the headphones to a portable media player,
mobile phone, tablet, or other mobile device.