northsiderap
Well-known member
Here a picture of my third mic capsule. Things are getting progressively better with each try. This one is a hypercardoid with a 1/2 inch diaphragm. There is a pressure outlet directly beneath both the primary and secondary harmonic of the diaphragm, and other damping holes cocentrically. I drilled them with a hand drill, so they are not exact by any means.
The diaphragm is about 25 microns thick (1 mil) as I cannot find a supplier for the proper material. Any suppliers would be appreciated, or we could do a bulk buy if anyone's interested. I'm guessing a 5-6 micron diaphragm would not only greatly increase the sensitivity of the mic, but also reveal refinements that I would have to make to the backplate.
The capsule was tested on the reference mic head amplifier, but I have an FET/Transformerized head amp design just about ready. How important are constant current sources in a single FET head amp design? How about with an FET followed by a DC class A and emitter follower output design? How about if the mic is going to have an independant power supply?
Anyone else doing this? Any advice? I'm also doing ribbon mics, but still working on the high frequency response. There's a nice thread on the ribbons elsewhere on this site.