Chinese Ribbon Mic Question

[chris319]

Here is a question about generic made-in-China ribbon mics.

There are two red wires attached above the ribbon which extend down the length of the motor to one side of the transformer primary. There are likewise two wires of some other color attached below the ribbon to the opposite side of the transformer primary. I understand that the longer red wires act as a hum-buck coil. Is there any particular reason why there are two wires coming from the bottom of the ribbon to the transformer? Do these have any effect on hum-bucking?

I am bringing a cheap ribbon mic back to life after being "overmodified". While I'm in there, is there any way to improve on the basic design or construction of the stock hum-bucking coil? Does the position or distance from the ribbon make a difference?

Thanks.

 

[pucho812]

sounds to me from the description that they are using twisted pairs for each side of the ribbon to connect to the transformer.  Something like the photo below.

The twisted pair will do nothing for hum-bucking. one can look at the ribbon as a single coil and in order to get "hum-bucking" would have to wire two ribbons in series exactly like 2 single coil pickups are wired in series in to make a hum-bucker pickup.


the twisted pair does help cancel out electromagnetic interference (EMI)

 

[chris319]

Thanks for the drawing!