Compact Stereo with T1 ToneMatch® Audio Engine
For the L1 Compact connect to Channel 2 with the volume straight up. You may want to fine tune that a bit but it should be a reasonable starting point.
For full details about how to set up the T1 ToneMatch® Audio Engine for this application please see: T1 ToneMatch® Audio Engine / USB / Output Stereo to Two L1®s