Mic Building:Wiring a double sided condenser capsule into a single sided circuit

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
May 5, 2009
Messages
5
Location
Australia
Hi there,

I want to connect a double sided K47 style condenser microphone capsule onto a mic preamp circuit designed for a single sided capsule. I'm thinking of using a km84 circuit. Am I right in thinking that if I wire the back diaphragm to the same point as the front diaphragm I get an omni pickup, and if I connect the back diaphragm to the central backplate I get a cardioid pickup pattern?

Is it better to leave the back diaphragm totally unconnected for cardioid? What's the difference between unconnected, and connected to the the central backplate?

Is it possible to put a switch on that line to switch omni to cardioid? What considerations are there for that switch considering the very high impedance circuit at that point?

I'm new to this idea of building a microphone. Interested in whether I'm on the right approach.

Regards
Crispin
 
look inside a neumann 147 it uses a double sided capsule and IIRC is the same one in a neumann 149. Anyway only one side is wired up in those 147 which gives it cardioid.
 
Better to leave it unconnected. Connecting to the backplate just makes the S/N ratio inferior.
 
Would a separate power connection for the back side help with the signal to noise ratio? Maybe adapting some ideas from the KM 86 circuit into the km 84 to get separate power connections for the front and back sides of the capsule. Something I have been looking into.
 

Latest posts

Back
Top