dynamic mic in to a soundcard

[Error_404]

Hey, i've got an audigy2 soundcard in my computer, and someone told me
that i can't use my dynamic mic straight in to the microphone port on
account of a 3V DC bias that'd cause problems with dynamic mics but is
needed for condensors. now, keeping in mind i have no idea what he's
talking about, is there any ways to fix this?

[Andrew M.]

Error_404 wrote:
> Hey, i've got an audigy2 soundcard in my computer, and someone told me
> that i can't use my dynamic mic straight in to the microphone port on
> account of a 3V DC bias that'd cause problems with dynamic mics but is
> needed for condensors. now, keeping in mind i have no idea what he's
> talking about, is there any ways to fix this?

There should be no problem plugging in a dynamic mic. If I am not
mistaken, dynamic mic's essentially ignore phantom power.

[Arny Krueger]

"Error_404" > wrote in message


> Hey, I've got an audigy2 soundcard in my computer, and someone told me
> that i can't use my dynamic mic straight in to the microphone port on
> account of a 3V DC bias that'd cause problems with dynamic mics but is
> needed for condensers. now, keeping in mind i have no idea what he's
> talking about, is there any ways to fix this?

The voltage is applied through a current-limiting resistor. Given the low
audio quality of the mic input circuitry on Sound Blaster sound cards, it
probably won't cause many more significant additional problems. The voltage
is too low to be meaningful or helpful to just about all quality condenser
mics.

[Jack Kontney]

"Arny Krueger" > wrote in message >...
> "Error_404" > wrote in message
>
>
> > Hey, I've got an audigy2 soundcard in my computer, and someone told me
> > that i can't use my dynamic mic straight in to the microphone port on
> > account of a 3V DC bias that'd cause problems with dynamic mics but is
> > needed for condensers. now, keeping in mind i have no idea what he's
> > talking about, is there any ways to fix this?
>
> The voltage is applied through a current-limiting resistor. Given the low
> audio quality of the mic input circuitry on Sound Blaster sound cards, it
> probably won't cause many more significant additional problems. The voltage
> is too low to be meaningful or helpful to just about all quality condenser
> mics.

Month after month, this is the most frequently asked question at Shure...

http://shure.com/support/technotes/app-soundcard.html

-Jack Kontney
Shure Inc.

[Arny Krueger]

"Jack Kontney" > wrote in message
om
> "Arny Krueger" > wrote in message
> >...
>> "Error_404" > wrote in message
>>
>>
>>> Hey, I've got an audigy2 soundcard in my computer, and someone told
>>> me that i can't use my dynamic mic straight in to the microphone
>>> port on account of a 3V DC bias that'd cause problems with dynamic
>>> mics but is needed for condensers. now, keeping in mind i have no
>>> idea what he's talking about, is there any ways to fix this?
>>
>> The voltage is applied through a current-limiting resistor. Given
>> the low audio quality of the mic input circuitry on Sound Blaster
>> sound cards, it probably won't cause many more significant
>> additional problems. The voltage is too low to be meaningful or
>> helpful to just about all quality condenser mics.
>
> Month after month, this is the most frequently asked question at
> Shure...
>
> http://shure.com/support/technotes/app-soundcard.html

This has been a nice article for a long time, but you've been updating it,
right?

[Brandon Anderson]

See bellow.

--

____________________________________

Brandon Anderson
Lighting, Sound, and Video

http://www.bdanderson.com/


"Error_404" > wrote in message
...
> Hey, i've got an audigy2 soundcard in my computer, and someone told me
> that i can't use my dynamic mic straight in to the microphone port on
> account of a 3V DC bias that'd cause problems with dynamic mics

No, dynamic mics do just fine with 48V Phantom power all the time. 3V won't
hurt them.

>but is
> needed for condensors. now, keeping in mind i have no idea what he's
> talking about, is there any ways to fix this?

Condenser? The only type of mic that is condenser based and will work with
just 3V is an electret. That is what is in most of those for-pc mics that
computer stores sell. You can buy one for a couple of dollars from Radio
Shack! They are omni-directional and sound like ****. I'd go with a
dynamic or, if you have the cash, get a small console or mic pre with
Phantom power and a real condenser mic and go into the line in on the card.
Or get a cheap console or pre amp and use it to sent the dynamic to the
card. Sound card pres are usually poor quality to begin with, so you would
be much better off finding a way to use the line in.

[Mike Rivers]

In article > writes:

> > > Hey, I've got an audigy2 soundcard in my computer, and someone told me
> > > that i can't use my dynamic mic straight in to the microphone port on
> > > account of a 3V DC bias that'd cause problems with dynamic mics

> Month after month, this is the most frequently asked question at Shure...
> http://shure.com/support/technotes/app-soundcard.html

There are some good tips in there, but unless I missed it, it doesn't
really address the question (or rather the questions that should have
been asked), and that's whether:

1. (You probably know the answer to this one) Will the bias voltage
affect the SM57? Because of the limited current, I doubt that it
will send the diaphragm slamming into the wind screen (or back into
the body) but putting a DC bias on a transformer could affect its
linearity or headroom.

Turns out that this is actually addressed in another application note:
http://www.shure.com/support/technotes/app-phantom1.html, which
is referenced in the above app-soundcard note. It says (briefly) that
a dynamic mic should not be used with an input that provides bias
voltage due to the possibility of damage to the mic (a safe answer),
but that it's possible to install a blocking capacitor (value unspecified)
to block the DC from the microphone. It would certainly be feasable to
make a special cable with an XLR on one end, a mini plug on the
other, and a 20 uF or so capacitor in series with the hot lead.

2. (You probably don't want to answer this one because of liability
issues) Will the current drain caused by connecting the mic to the
sound card mic input with a bias voltage, essentially a short
circuit to the bias voltage source, damage the sound card?

I suspect that the answer to both is "no" but the orignial poster
probably wants to hear it from someone who has actually tried it and
not blown up an SM57 or an Audigy card.




--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Mike Rivers]

In article > writes:

> No, dynamic mics do just fine with 48V Phantom power all the time. 3V won't
> hurt them.

Not 3 volts applied between Pins 1-2 and also Pins 1-3, but not
between hot and ground as would be the "bias" voltage on an unbalanced
mic input typical of the sound cards designed to be used with those $5
condenser mics that you buy at computer storres.



--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Brandon Anderson]

What? Let me re-word what you wrote here so that you can see how you
contradicted yourself:

--

____________________________________

Brandon Anderson
Lighting, Sound, and Video

http://www.bdanderson.com/


"Mike Rivers" > wrote in message
news:znr1069793761k@trad...
>
> In article >
writes:
>
> > No, dynamic mics do just fine with 48V Phantom power all the time. 3V
won't
> > hurt them.
>
> Not 3 volts applied between Pins 1-2

Not three volts applied between ground and hot
>and also Pins 1-3

and also ground and cold.

>, but not
> between hot and ground as would be the "bias" voltage on an unbalanced
> mic input typical of the sound cards designed to be used with those $5
> condenser mics that you buy at computer storres.

Layout of XLR cable:
Pin 1 = Ground
Pin 2 = Hot (Phase)
Pin 3 = Cold (Neg Phase)

So you just contradicted yourself by saying that between 1 and 2 works but
not hot and ground.

>
>
>
> --
> I'm really Mike Rivers - )
> However, until the spam goes away or Hell freezes over,
> lots of IP addresses are blocked from this system. If
> you e-mail me and it bounces, use your secret decoder ring
> and reach me here: double-m-eleven-double-zero at yahoo

[Chris Hornbeck]

On Tue, 25 Nov 2003 13:02:06 -0600, "Brandon Anderson"
> wrote:

>See bellow.

No sense bellowing.

Phantom power doesn't appear across a floating mic.
Sound card power does. Different stuff.

Chris Hornbeck
"That is my Theory, and what it is too."
Anne Elk

[Scott Dorsey]

In article <znr1069793761k@trad>, Mike Rivers > wrote:
>In article > writes:
>
>> No, dynamic mics do just fine with 48V Phantom power all the time. 3V won't
>> hurt them.
>
>Not 3 volts applied between Pins 1-2 and also Pins 1-3, but not
>between hot and ground as would be the "bias" voltage on an unbalanced
>mic input typical of the sound cards designed to be used with those $5
>condenser mics that you buy at computer storres.

That is NOT phantom power. It's something very different, and folks who
call it phantom power should be ashamed.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers]

In article > writes:

> What? Let me re-word what you wrote here so that you can see how you
> contradicted yourself:

> Layout of XLR cable:
> Pin 1 = Ground
> Pin 2 = Hot (Phase)
> Pin 3 = Cold (Neg Phase)
>
> So you just contradicted yourself by saying that between 1 and 2 works but
> not hot and ground.

Hold on a bit before you start throwing around your insults. That's
the layout of an XLR for a conventional balanced microphone connected
to a conventional mic preamp, with or without phantom power.

Phantom power is applied between pins 1-2 (1 is minus, 2 is plus) and
also between pins 1-3 (1 is minus, 3 is plus). Therefore, there is no
potential difference, hence no applied voltage, between pins 2 and 3,
the signal leads for the microphone.

The "bias power" input that we're discussing here is unbalanced, and
there's voltage between the signal lead (on the input jack) and the
ground, or low side. Now in order to make a conventional microphone
work with that input, you need to connect pins 2 and 3 to the input
jack, pin 2 to the hot terminal, and pin 3 to the low, or ground
terminal. Now, you have the bias voltage appearing between pins 2-3 of
the microphone, putting voltage across the transformer, or the coil if
there's no transformer.

Where Pin 1 comes into play here is that normally carries the cable
shield on the XLR, and the cable shield is also connected to the low
side of the unbalanced input jack. So Pin 1 is connected to Pin 3.

So where's the contradiction?


--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo