According to the Roland site, the
VS-890 does not support WAV import/export. Neither the Roland nor the Yamaha have digital ins/outs. That means you have to run the digital signal through the D/A converter on the Roland, send the audio to the analog inputs on the Yamaha, and go through yet another A/D conversion. That
will have an impact on the audio, since neither model has great converters, but you might not notice the impact.