Cheap 'n easy mic body... UPDATED!

jhaell · Dec 28, 2021

pinchemotherloaf said:
Wow, that looks great! You made it yourself, that's cool! That capsule looks pretty decent too.

Thanks! Not quite as neat and clever as your use of strainers, but It does the job. I'll see if I can dig up some sound-examples.

rmburrow · Dec 28, 2021

pinchemotherloaf said:
Yes, you caught that! I know what you mean, but surprisingly enough it works fairly well! Anode is at 200V (2.5 mA.) Maybe the higher voltage makes up some of the difference?

IMO it's not necessarily the voltage but certainly dc current in the primary affects the transformer response. The core gap prevents (closed path) core saturation with dc in the primary. The gapped core still magnetizes with DC in the primary to a lesser extent. It would be interesting to see frequency sweeps of that transformer, one with no dc in the primary, another with 2 ma in the primary, and another with 10 ma (rated current) in the primary, with the secondary terminated in a resistor load. One thing for sure, that transformer was manufactured for high reliability with that MIL-spec number, back in the days MIL-spec meant something.

pinchemotherloaf · Dec 28, 2021

rmburrow said:
IMO it's not necessarily the voltage but certainly dc current in the primary affects the transformer response. The core gap prevents (closed path) core saturation with dc in the primary. The gapped core still magnetizes with DC in the primary to a lesser extent. It would be interesting to see frequency sweeps of that transformer, one with no dc in the primary, another with 2 ma in the primary, and another with 10 ma (rated current) in the primary, with the secondary terminated in a resistor load. One thing for sure, that transformer was manufactured for high reliability with that MIL-spec number, back in the days MIL-spec meant something.

That's interesting info. I just tossed that xformer into the mix as it was on hand. 'Experimental' and I didn't have too much expectation on it. Listening to the response (in my AT cans) bears some semblance to an audio spectrum...