On Tue, 11 May 2004 23:40:32 +0100, Paul Burridge
wrote:

On Tue, 11 May 2004 14:28:31 -0500, John Fields
wrote:

On Tue, 11 May 2004 19:49:18 +0100, Paul Burridge
wrote:

HI

Anyone know or care to guess what the typical impedance of a condenser
mic is?

---
Electret or straight RC?

Electret. Someone told me they're also now available with a SMD
transistor amp built-on.
Just a ball-park figure would suffice.

---
Roughly the value of the load resistor, but take a look at this:

http://www.hut.fi/Misc/Electronics/c..._powering.html

--
John Fields

Paul Burridge wrote in message . ..
HI

Anyone know or care to guess what the typical impedance of a condenser
mic is?

Generally within an order of magnitude of 1e12/s. Or did you mean an
electret with built-in amplifier? Two wire, or three? ... Do a
Google search for "electret microphone impedance."

Cheers,
Tom

Paul Burridge wrote in message . ..
HI

Anyone know or care to guess what the typical impedance of a condenser
mic is?

Generally within an order of magnitude of 1e12/s. Or did you mean an
electret with built-in amplifier? Two wire, or three? ... Do a
Google search for "electret microphone impedance."

Cheers,
Tom

On 12 May 2004 06:25:09 GMT, "Walter Harley"
wrote:

"Paul Burridge" wrote in message
.. .
Anyone know or care to guess what the typical impedance of a condenser
mic is?

Easiest way to answer that would be to go look at some manufacturer specs.

I'll ignore the distinction between electret and condensor and going with
common usage, and assume, without justification, that you are talking about
the output impedance at the XLR connector of a balanced mic. In other
words: you want to know what the output impedance of, say, a Shure SM87 or
an Audio-Technica AT4033 is. Answer, based on a quick nonsystematic sample:
about 100 ohms on average.

But I'm not sure why you care. Like the rest of pro audio, they're not
intended to be loaded by an equal impedance. Generally they want to see
around 1k.

As others have noted, this has nothing whatsoever to do with the impedance
of the actual mic element, which is basically a capacitor with a fixed
charge on it.

Thanks, but I appreciate that, Walter. This is simply for simulation
purposes. I just need to have a value to bung in the signal source box
or the gain of this amp stage will not be meaningfully calculable.

--

"What is now proved was once only imagin'd." - William Blake, 1793.

On 12 May 2004 06:25:09 GMT, "Walter Harley"
wrote:

"Paul Burridge" wrote in message
.. .
Anyone know or care to guess what the typical impedance of a condenser
mic is?

Easiest way to answer that would be to go look at some manufacturer specs.

I'll ignore the distinction between electret and condensor and going with
common usage, and assume, without justification, that you are talking about
the output impedance at the XLR connector of a balanced mic. In other
words: you want to know what the output impedance of, say, a Shure SM87 or
an Audio-Technica AT4033 is. Answer, based on a quick nonsystematic sample:
about 100 ohms on average.

But I'm not sure why you care. Like the rest of pro audio, they're not
intended to be loaded by an equal impedance. Generally they want to see
around 1k.

As others have noted, this has nothing whatsoever to do with the impedance
of the actual mic element, which is basically a capacitor with a fixed
charge on it.

Thanks, but I appreciate that, Walter. This is simply for simulation
purposes. I just need to have a value to bung in the signal source box
or the gain of this amp stage will not be meaningfully calculable.

--

"What is now proved was once only imagin'd." - William Blake, 1793.