Please don't modify your existing power adapters...
The DL4 requires a power supply that can provide 9 volts of "AC" (not DC like most pedal effect power adapters!) power with at least 1500mA of current. You probably won't find too many power supplies out there that will fit the bill, so we always recommend that you stick to using the Line 6 "PX2" power adapter, as these are designed to provide the correct power voltage and current requirement our POD's and DL4's require.
Most power bricks comes with different kinds of cables and voltage opportunities. I had the same problem as you had when my DL4 started blinking wich is a sign of low battery, but i found out that the blue cable that came with my FuelTank fitted into the DL4! What a lifesaver.