I have a vintage Neumann KM56 on the bench, I've replaced the faulty polar pattern switch with a replacement from Soundlock Engineering. Unit is working again and the polar patterns switch nicely now.
It seems to have a bit of 120hz hum, the supply has been recapped with modern caps and measures 130V DC on the B+ and 4.3V DC on the heaters.
Does anyone know if this mic has a fairly high hum? The mic is still usable, just not the quietest. With 20db of gain from my mic pre the 120hz hum is coming in around -70dbfs
Is there anything in particular I can check for regarding the hum aside from typical culprits?
It seems to have a bit of 120hz hum, the supply has been recapped with modern caps and measures 130V DC on the B+ and 4.3V DC on the heaters.
Does anyone know if this mic has a fairly high hum? The mic is still usable, just not the quietest. With 20db of gain from my mic pre the 120hz hum is coming in around -70dbfs
Is there anything in particular I can check for regarding the hum aside from typical culprits?