Just in case anyone is interested, I figured out an alternate method to do this with no out-of-sync issues. I did it with Audacity so it can be done via Windows, Mac, etc. It's pretty simple, although not perfect considering the nature of the DR-1 and it's actually intended purpose, but it does work and sounds decent. 1. Record the first track (A) in mono on the DR-1. 2. Set the DR-1 to overdub in stereo ala the instructions. And make sure the mix balance is set to maximum as per Randy's direction. 3. Record track B. 4. Import track B into Audacity. 5. Split the stereo image 6. Select one wave form completely, i.e. the right channel, and use the "Invert" effect. 7. Set both channels to mono. 8. Hit play and enjoy your isolated "B" track. 9. Use "Quick Mix" or "Export" to mix the file to one track. 10. Use multi-tracking software to add stereo effects if that is your desire. --In addition to Randy's idea, I also found this following youtube video insightful. It pretty much sums up the whole concept of phase inverting with Audacity:
Good luck and enjoy!
