Reverse polarity

I have a track that I recorded where both vocals and ukulele were recorded at the same time. I’ve come back to this track after not listening to it for a few months. When the two tracks are played together the vocal goes all phasey/old radio on me haha. However, when tracks are soloed they sound fine. I’m thinking I may need to flip the polarity of one of the tracks…???

If so then how do I change this in C8, the last version I used was C5


It’s in the “Pre” section on the Mix Console. Make sure that rack is expanded and you’ll see a phase reverse button at the bottom of the Pre rack.

I didn’t know that section. It’s very convenient, even the gain and filters, thanks!