If the signal is distorting, start out by checking your cables and try a second microphone.
Always match the Impedance of the mic to the ADL 700. The Neumann TLM 103 has an impedance of 50Ohms so set the knob on the ADL to 150.
Start flat by bypassing your compressor and EQ. Use the Gain knob before using the Trim knob.
Your room can also factor into this situation. Using a lot of gain in a noisy room could ruin a vocal take with unwanted background noise or hiss.