I seem to recall that when I initially built an unbalanced version of the DB25 connector for use with the H9K, I had problems when I grounded the cold pins too. That said, what I ended up doing was just buying a commercially available DB25 to 8x 1/4″ TRS cable and then plugged the 1/4″ TRS into a standard unbalanced 1/4″ TS output…. and it worked just fine. I am not at my system right now but I suppose I could/should go check to see if the R ing is grounded.,
