As was discussed in New Orleans in 2010, when you run both channels at the same time, (one forwards, one backwards), the one running backwards will have its phase or polarity reversed.

     On Monday, March 9, 2015 3:43 PM, Dave Radlauer <[log in to unmask]> wrote:

 Hi Tom, long time.

I've had no problem dubbing mono 1/2 or 1/4 track simultaneously.
In my case from *J-corder* modified Technics 1520s.

Dave Radlauer

hm# 510-848-8323
cell# 510-717-5240