In Sonar first you select Loop then click the beginning and end of your loop, select Punch record and click in the time line where you want punch in and out to start then press record.

Sonar will loop over designated area and punch in at the appropriate time and stop at end of loop and do again until you stop.

This provides an amount of pre- roll. It's very easy to set up and very fast.

https://www.cakewalk.com/...elp=Recording.26.html#