The power requirements for the MPS-400 and MPS-420 are a bipolar power supply with output voltages of ± 12 VDC to ± 22 VDC. This supply should be well regulated with low ripple and noise and should be capable of the appropriate load current. Additionally, if phantom power is to be used with condenser microphones, then a +48 VDC supply will be needed. Again, it will need to be a supply with low ripple and noise, capable of the appropriate load current. The power supply ground is common for both the low voltage ± supply and the high voltage phantom supply.