When starting Vital in Linux, the audio defaults to alsa. There is a harsh distortion on all sounds. I was thinking that this was a really ugly sounding synth but when I switched to Jack it sounded lovely. I don’t know if anyone else has noticed this but it is the same on both of my computers with different distros. Also as someone pointed out on the forums is that if I set my audio to Jack, it doesn’t save that setting next time I open the program.
Alsa and pulseaudio are sometimes not up to the task to handling all the audio from a DAW or a synth as involved as Vital. I use it in Bitwig, which starts Jack by default and some patches still cause overruns. I increased the buffer from 512 to 1024 and that seems to have done the trick for me.