Tieline VIA User Manual page 5

Step 3. Connect the Via to the laptop & the BOSE speaker
Plug the audio cable (green) 3.5mm stereo
plug into the Stereo Line In 3.5mm plug on
the Via right hand side, also plugging the
other end into the Headphone Out socket on
the laptop. This takes the music feed from
Station Playlist on the laptop into the VIA for
the radio broadcast.
Next, connect the XLR cable (3 prongs) from
the Output 1 plug on the right hand side of
the VIA into to the external speaker (BOSE).
When connecting the cables, make sure the
volume knobs on the external speaker are
turned to OFF. That way you won't send
everyone deaf when you test after powering
up.
No other connections required for this side of the Via.