I have a little computer mic that expects 5V on the connector. Is there a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer) I
don't know of a way to get the 5V into the mic.

In article ,
Carey Carlan wrote:
I have a little computer mic that expects 5V on the connector. Is there a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer) I
don't know of a way to get the 5V into the mic.

try this:


+ 9V (from 9V battery)
|
|
\
/
\ 2.2K ohm
/
\
|
|
mic T----+-------||---------T
10 uF output
S----+------------------S
|
|
|
battery gnd
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Carey Carlan wrote:
I have a little computer mic that expects 5V on the connector.
Is there a simple way to connect this directly to a decent preamp?
Building custom cables is not a problem, but (aside from pulling
power from my computer) I don't know of a way to get the 5V
into the mic.

If it is a 2-pole connector, then Scott Dorsey's circuit is
the one you need. However many "computer mics" use
3-pole connectors and dedicate the ring of the stereo
mini-phone connector to the 5v bias.
Complete discussion here....
http://www.epanorama.net/links/pc_so...ml#interfacing
http://www.epanorama.net/circuits/mi...html#soundcard

A couple days ago a fellow emailed me about a circuit to use
his "plug-in-power" mics with regulation 48V phantom
power balanced XLR inputs on his new camcorder. I suggested
a variation of Rick Chinn's P48 to T12 converter circuit...
http://www.uneeda-audio.com/phantom/p48t122.jpg
(with 5v zener, -audio cap to ground, and 2-3K bias resistor.)

Carey Carlan wrote:

I have a little computer mic that expects 5V on the connector. Is there a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer) I
don't know of a way to get the 5V into the mic.

Why would you want to connect a cheap and nasty *computer mic* to a decent
pre-amp ?

Just asking.


Graham

Pooh Bear wrote in
:

Why would you want to connect a cheap and nasty *computer mic* to a
decent pre-amp ?

Variety. To get that nasty computer mic sound without succumbing to the
nasty noise created by the ugly computer sound card.

Carey Carlan wrote:

Pooh Bear wrote in
:

Why would you want to connect a cheap and nasty *computer mic* to a
decent pre-amp ?

Variety. To get that nasty computer mic sound without succumbing to the
nasty noise created by the ugly computer sound card.

Ok !

Graham

"Pooh Bear" wrote ...
Carey Carlan wrote:

I have a little computer mic that expects 5V on the connector. Is there
a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer)
I
don't know of a way to get the 5V into the mic.

Why would you want to connect a cheap and nasty *computer mic*
to a decent pre-amp ?

You might need a "throw-away" mic for certain things. The guys over on
r.a.m.p.s talk about keeping an old beater dynamic in their it for capturing
things like gunshots, etc.

The guy that emailed me wanted to use his existing consumer stereo
mics with his new XLR-equipped camcorder because now he can't
afford new mics until he recovers from paying for the camcorder. :-)

Pooh Bear wrote:
Carey Carlan wrote:


I have a little computer mic that expects 5V on the connector. Is there a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer) I
don't know of a way to get the 5V into the mic.


Why would you want to connect a cheap and nasty *computer mic* to a decent
pre-amp ?

You'd be surprised how accurate these little electret
condensers actually are if you give their signal a good
chance to get recorded. They are relatively noisy, as are
all very small condensers, and there may be a broad presence
bump in the upper mids but their responses tend to be
exceptionally smooth.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

In article ,
Carey Carlan wrote:
Pooh Bear wrote in
:

Why would you want to connect a cheap and nasty *computer mic* to a
decent pre-amp ?

Variety. To get that nasty computer mic sound without succumbing to the
nasty noise created by the ugly computer sound card.

But the noise is half the fun! Also the preamp overload effects!

I still think communications mikes are more fun, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Bob Cain wrote:

Pooh Bear wrote:
Carey Carlan wrote:


I have a little computer mic that expects 5V on the connector. Is there a
simple way to connect this directly to a decent preamp? Building custom
cables is not a problem, but (aside from pulling power from my computer) I
don't know of a way to get the 5V into the mic.


Why would you want to connect a cheap and nasty *computer mic* to a decent
pre-amp ?

You'd be surprised how accurate these little electret
condensers actually are if you give their signal a good
chance to get recorded. They are relatively noisy, as are
all very small condensers, and there may be a broad presence
bump in the upper mids but their responses tend to be
exceptionally smooth.

Indeed, electrets tend to be pretty decent overall.

The application puzzled me though.

Graham

Pooh Bear wrote in
:

Indeed, electrets tend to be pretty decent overall.

The application puzzled me though.

The application is that I like the varied responses of microphones. I find
that even a "crappy" microphone will sometimes have just the sound I want.
I don't mind its distortions. For instance, this mic should be wonderful
for telephone simulations when properly band limited.

I do not, however, enjoy the very nonlinear distortions of my computer
sound card. It's the cheapo, on-mother-board type that makes noise from
video and mouse movements. Those distortions and the coarse ADC irritate
me.

Therefore, I want to know how to power the mic from a standard preamp.

Bob Cain wrote:

You'd be surprised how accurate these little electret
condensers actually are if you give their signal a good
chance to get recorded.

Who is surprised?

Letsee, how about a Chinese clone of a Pansonic WM64?

http://www.panasonic.com/industrial/...m64_mn_dne.pdf

They are relatively noisy, as are
all very small condensers, and there may be a broad
presence
bump in the upper mids but their responses tend to be
exceptionally smooth.

It seems like it is hard for really small mics to be
anything but smooth.

On Sun, 01 May 2005 02:56:04 GMT, Carey Carlan wrote:

Pooh Bear wrote in
:

Indeed, electrets tend to be pretty decent overall.

The application puzzled me though.

The application is that I like the varied responses of microphones. I
find
that even a "crappy" microphone will sometimes have just the sound I
want.
I don't mind its distortions. For instance, this mic should be wonderful
for telephone simulations when properly band limited.

I do not, however, enjoy the very nonlinear distortions of my computer
sound card. It's the cheapo, on-mother-board type that makes noise from
video and mouse movements. Those distortions and the coarse ADC irritate
me.

Therefore, I want to know how to power the mic from a standard preamp.

Take a look at some of the PZM modifications. The PZM probably uses a
similar capsule to your computer mic. I've had some success with a very
simple circuit which reduces 48V phantom power down to 5V with an Apple
Mac microphone - 3 resistors, a couple of capacitors and a zener diode -
but I'm not sure if I was just lucky with this particular combination of
mic and mixer.

Cheers.

James.

Carey Carlan wrote:

Therefore, I want to know how to power the mic from a standard preamp.

Near the end of this page there are several increasingly
complicated and better performing circuits using standard
phantom:

http://www.epanorama.net/circuits/mi..._powering.html


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein