Our studio has a Focusrite Scarlet 2i4 USB audio interface. It has four independent RCA outputs.
If I generate four mono tracks in Audacity, how can I send one separate track to each of the four outputs of the Scarlet.
The device manual is here, but there is no info provided on this function.
You cannot do this in Audacity. Audacity has a limit of only 1 mono or stereo ouput track. Sorry. 
Audacity has the capability to do multi-track recording with the right hardware. It does not do multi-track playback.
Thank you for your reply. If I save each of the four tracks in Audacity as a separate MP3, can you suggest an application to load them into that has multi track playback via USB?
The manufacturer usually provides at least one application that can get the hardware off the ground. It may not be fancy, but it usually does work. Check the Scarlett web site for drivers and applications. It’s not unusual for products to have their own user-administered web page, too.
Google your brains out.
You have another problem in that the 2i4 is an odd duck. The 2i2 is very popular followed by the 4i4. This is the first I’ve heard of a 2i4. Sometimes odd products such as this were made for a specific job or client and that could give you a hint where to go for solutions.
Koz
The free bundled software is Amplify Studio and Ableton. My editing needs are already covered in Audacity, so I was looking for a simple dedicated multiplayer. Years ago, someone wrote me a little program that worked in Win 95.
If I had to pick a full application, I would probably go with Cakewalk.
The 2i4, a standard model, is cheaper than the 4i4 and all I need for my application. Anyway, we already have it.