a mic of constant sorrow
- May 19th, 2016
- Posted in diy . studio
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I’ve been trying to build a carbon microphone. Why? Well, partly, because I can, and partly, because if you want that “telephone” sort of sound, the best way to do it is to use a telephone element rather than fake it later (see also: BULLHORN), and partly because I want to be able to sing into a can, like them fellers at the radio station.

A Microphone of Constant Sorrow
And this should be – electrically, at least – very simple. Small power supply – battery is fine – resistor or two, capacitor. Done. Very simple circuit.
But it isn’t working, and I have absolutely no idea why, and I’m highly frustrated. I’m going to try a higher-voltage circuit, which I’ve been avoiding for no good reason other than it shouldn’t help, but I’m starting to think the carbon element I got new-old-stock off eBay isn’t up to snuff.
Anybody else built one of these monsters before? I have actually managed to get extremely-low-volume recordings out of it a couple of times – far too low level to be useful, I’m afraid – so I don’t think the element is actually dead. But honestly, I have no idea.
eta: GUESS WHO HAS A WAVEFORM 😀

A WAV of Constant Sorrow
2 comments on Dreamwidth, 5 comments on Tsu.
Check your email, I sent you a message about the mic element!
http://www.modernbluesharmonica.com/board/board_topic/5560960/465298.htm
Ahh, see, he says in comments he switched out for a Shure CM element (transmitter, in carbon terms) at 3:50, which – while still from what I can read elsewhere is a very good blues harmonica pickup – is a magnetic technology, similar to a dynamic microphone. That’s why he doesn’t have any power source – he doesn’t need one with that class of pickup.
Carbon transmitters, by contrast, are basically variable resistors. And as such, need a power supply – they are in general completely different beasts, technologically speaking.
GUESS WHO HAS A WAVEFORM? 😀