Pattern Control Unit for M 49 V. NM V. This classical pattern control unit contains a mains transformer. It automatically switches between the 100-120 V and 220-240 V ac mains voltage ranges. In the OFF position the NM V draws no current. To ensure a long life, the tube is heated up gently, with current limiting. A very effective filtering inside the NM V ensures very high-quality operating voltages, with a minimum of residual noise voltages. Note: The new NM V is suitable in principle for operating all vintage Neumann microphones utilizing the AC 701 tube, such as the older M 49 and M 249. Older devices as N 52 (a, h) and NN 48 (a, b, h) are not suitable for operating the M 49 V, due to their current and voltage limitations. OPERATION WITH UNBALANCED INPUTS At the pattern control unit, the audio signal isavailable at a balanced, floating XLR 3 output. The output is wired as per IEC 60268-12 and IEC 61938: Pin 1: 0 V/groundPin 2: audio signal (+phase)Pin 3: audio signal (–phase) So pin 2 is the “hot phase”, pin 3 must be connected to ground when used with unbalanced inputs
