I have to transfer some old 1/4" 4-track tapes that were recorded on a Tascam 40-4 with a built-in dbx unit. I hope to be using an Otari MX5050 4 track machine to play the tapes on. I know that Tascam DX-4D units (which supposedly have the same type of dbx NR-I think it's type II) have a cable and special connector that plugs into the back of Tascam machines like the 34, 44, etc. What is the purpose of this cable and will the DX-4D work without it? Thanks in advance!