You will want to read the following setup guide from Nektar's web site.
http://www.nektartech.com/s.nl/ctype.KB/it.I/id.8576/KB.533/.f
The answer might be as simple as going into your External Devices window and double-clicking the device. Check the option to set the device as the default instrument. If you don't choose the option to set your device as a default instrument, you will need to open the Inspector window for the track that you have a virtual instrument loaded on and manually choose the Input.
We have included a few resources that may assist with helping to further your knowledge of our Studio One DAW. Compiled below are several links to Manuals, Videos, and our Forums; which will help you through the process of learning how to use Studio One.
The Manual
The manual in Studio One 3 is a great resource and starting point for when you have any questions about setup, usage, or wish to further your knowledge of the software.
http://support.presonus.com/entries/106757573--8-Where-Can-I-Find-the-Studio-One-3-Manual-
PreSonus YouTube Channel
https://www.youtube.com/user/presonusaudio
**The link above, indicated with an asterisk, has a category list on the right hand sidebar. This makes it easier to sift through the 100's of videos that are listed there.
PreSonus User Account:
Log into your user account and select the "My Products" link and then choose "My Products" then select the "Software" tab, click on the listing of your registered software (View More Details). Scroll down to the bottom of the page to locate the "Learn" section. You will find a list of videos there that are a tutorial set of Studio One "how to usage" videos.
Exchange
Exchange is the official community hub for sharing user-created content for Studio One!
http://studioone.presonus.com/exchange
PreSonus Studio One Forum
The PreSonus Forums host plenty of community interaction for Studio One. Get involved!
https://forums.presonus.com/viewforum.php?f=96&sid=816031875d749dacee620de245384f2a
Third party tutorial sites:
lynda.com
An excellent resource for Studio One beginners can also be found on the learning resource lynda.com. Check out the two-hour course at this link.
http://www.lynda.com/nmhpexp4
macProVideo
Studio One training videos have hit macProVideo.com and are available here. With over two hours of extensive video training for Studio One 2, this is an excellent resource for musicians of all skill levels. Focused on songwriting, the 22 sections of the course cover every aspect of the software, from basic setup to mixing and mastering your final project.
Obedia
If Studio One training one-on-one, with a real human, is what you require, there are few better resources than Obedia.com. We have partnered with Obedia to provide Studio One training from the beginner to advanced level.
https://www.macprovideo.com/
Groove3
Groove3’s tutorial videos are available at groove3.com. These in-depth videos will get you up and running quickly with Studio One. Groove3 also hosts videos about a multitude of other audio programs and techniques that you may find useful. If you’re interested in Studio One and in digital recording techniques in general, Groove3 is a superb choice. The videos are inexpensive and can be streamed from anywhere.
https://www.groove3.com/
Studio One Expert
For Independent Studio One news, tips, tricks and more. Studio One Expert is part of the Production Expert Community.
http://www.studio-one.expert/
Home Studio Trainer
A great source for learning studio tips and tricks. All examples and videos are done with Studio One!
http://homestudiotrainer.com/
Unofficial Studio One Facebook Group
Interact with other Studio One users on Facebook!
https://www.facebook.com/login/?next=https%3A%2F%2Fwww.facebook.com...
