JLM Audio
Well-known member
Not sure how Neumann do it in the N48R power supply but below is a simple way that should work fine.
The 2.6mA load of the microphone would give about 1.4v drop per step which should be close enough. Otherwise a resistor load could be added to the end of the diode string to 0v to trim the voltage drops to exactly 1.5v steps. To stop popping when switching use a shorting type switch or add a capacitor to 0v where the 6k8 resistors join the switch.
This would be easily added to our Go between PCB by adding the 5 position switch and 8 diodes and wiring it in place of the 470R resistor closest to the 2 x 6k8 resistors on the PCB. You would just need to set the 48v to exactly 51v with the 25turn trim pot if using our AC/DC or Power station PCB.
The 2.6mA load of the microphone would give about 1.4v drop per step which should be close enough. Otherwise a resistor load could be added to the end of the diode string to 0v to trim the voltage drops to exactly 1.5v steps. To stop popping when switching use a shorting type switch or add a capacitor to 0v where the 6k8 resistors join the switch.
This would be easily added to our Go between PCB by adding the 5 position switch and 8 diodes and wiring it in place of the 470R resistor closest to the 2 x 6k8 resistors on the PCB. You would just need to set the 48v to exactly 51v with the 25turn trim pot if using our AC/DC or Power station PCB.
