Note: This article only applies to Apollo Thunderbolt Desktop models with Line 3/4 outputs.
There are a couple of scenarios where you may want to send a separate mix to the Line 3/4 outputs on your Apollo Thunderbolt Desktop - for example, if you need to send a custom headphone mix that is different from your monitor mix to a headphone amp, or if you want to send a stereo signal to a piece of outboard gear for processing. This article explains how to set up the Line 3/4 output on the Apollo Twin for these kinds of scenarios.
The routing to the Line 3/4 outputs on the Apollo Twin is managed via the CUE OUTPUTS popover, which is accessed by clicking the CUE OUTPUTS button on the right side of the Console window:
There are two available SOURCE options for the Line 3/4 output - "LINE 3/4" and "MIX":
To send a separate, discrete mix to the Line 3/4 outputs, set the SOURCE to "LINE 3/4". This is most commonly used when sending a custom headphone mix to a headphone amp via the Line 3/4 outputs, or when sending a stereo signal out to an outboard piece of gear for processing. Once the SOURCE is set to LINE 3/4, signal can be sent directly to these outputs by selecting the Line 3/4 outputs within the DAW.
To mirror the monitor mix to the Line 3/4 outputs, set the SOURCE to "MIX". This will route any signal being sent to the Monitor L/R outputs to the Line 3/4 outputs as well. This is useful for sending the monitor mix out to a headphone amp if a discrete headphone mix is not needed.
Note that when the SOURCE is set to "MIX", full line level signal is sent out of the Line 3/4 outputs with no volume control. If volume control is needed when sending the monitor mix to the Line 3/4 outputs, we recommend using the ALT Monitoring feature in Console or an external volume control. For details on ALT Monitoring, see the "ALT Monitoring Overview" section of the Apollo Software Manual.
Note: The "MIX" source is labeled "MON" in UAD 9.0.2 and older.
If "LINE 3/4" is unavailable as a SOURCE option in Console, check Console > Settings > Hardware and make sure ALT COUNT is set to "0" as shown in the screenshot below. If ALT COUNT is set to "1", the Line 3/4 outputs will be unavailable for routing from the DAW.