ofxStk DrawSynth setDevice id

instead of using

ofSoundStreamSetup(2, 0);

create a member variable in ofApp

ofSoundStream myStream;

and in the setup do

    myStream.setDeviceID(3);
    myStream.listDevices();
    myStream.setup(this, 2, 0, 44100, 256, 4);

and remove the call to ofSoundStreamSetup(2, 0)