Problem 1. Unwanted sounds:
I've noticed that the output on the 2496 Audiophile
produces little sounds whenever the mouse is
moved. This is also true anytime the hard drive is
accessing. Is there a workaround for this annoyance?

Problem 2. Sound card input impedance.
The sound card has an input impedance of10K ohms
minimum. I believe this would indicate that the sound
card is not sensitive to the output impedance of the
driving device.

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

"Powell" wrote in message

Problem 1. Unwanted sounds:

I've noticed that the output on the 2496 Audiophile
produces little sounds whenever the mouse is
moved. This is also true anytime the hard drive is
accessing. Is there a workaround for this annoyance?

Not an terribly uncommon problem, but not a problem that is seen in every AP
2496 installion. It could be due to grounding problems in the case or
motherboard, it could be due to IRQ sharing issues, or it could be due to
PCI bus domination problems. Usual solutions involve making sure the system
board is tightened down well, moving the card to other PCI slots, and
turning off video card performance features that tie up the CPU bus.

Problem 2. Sound card input impedance.
The sound card has an input impedance of10K ohms
minimum. I believe this would indicate that the sound
card is not sensitive to the output impedance of the
driving device.

Why would this be a problem? Insensitivity to the output impedance of the
driving device is generally considered to be a good thing. A 10K input
impedance is average-to-high for a piece of audio production equipment.

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound card that remains below
clipping, to optimize noise performance.

"Arny Krueger" wrote

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound
card that remains below clipping, to optimize noise
performance.

The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

6.02 volts.

Powell wrote:
"Arny Krueger" wrote


Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound
card that remains below clipping, to optimize noise
performance.


The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

"S O'Neill" wrote

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound
card that remains below clipping, to optimize noise
performance.


The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

6.02 volts.

Ok. Microphone pre-amp output is +22 dBu. What
voltage does this represent?

"Powell" wrote in message

"Arny Krueger" wrote

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound
card that remains below clipping, to optimize noise
performance.

The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

+2 dBV is about 1.26 volts.

"S O'Neill" wrote in message


Powell wrote:

"Arny Krueger" wrote

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card. My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms, 1 V/1.2 K-ohm or
250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load). Are there any technical
advantages to any of these combinations sited or is it
strictly by ear?

You want to apply the largest voltage to the sound
card that remains below clipping, to optimize noise
performance.

The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

6.02 volts.

That would be more like +15.56 dBV.

+2 dBV is about 1.26 volts.

In article writes:

I've noticed that the output on the 2496 Audiophile
produces little sounds whenever the mouse is
moved. This is also true anytime the hard drive is
accessing. Is there a workaround for this annoyance?

Probably not. Maybe a different computer with better grounding and
shielding would help, but the best policy is not to move the mouse
when you need for the card to be quiet.

The sound card has an input impedance of10K ohms
minimum. I believe this would indicate that the sound
card is not sensitive to the output impedance of the
driving device.

It's more like the other way around - the card won't adversely affect
what's driving it.

Looking at my options I could connect the microphone
preamp (300 ohms, RCA) directly to the input of the
sound card or connect the microphone preamp to the
input of a stereo preamp and then output to the sound
card.

Lose the stereo preamp. You don't need it and it's just extra stuff to
make noise and add distortion.

My choices of stereo preamps have the following
out impedances: 150 mV/0.6 K-ohms

Quite inappropriate for feeding your sound card. The impedance isn't
the issue, but the output voltage is pretty low.

1 V/1.2 K-ohm or 250 ohms (no voltage reference provided but has 2V
RMS output into 60 K ohm load).

That's more like it, but unless your unnamed mic preamp (does it
REALLY have a 300 ohm output impedance) doesn't have enough output
level at full gain to drive the sound card to a full scale digital
output from whatever source you're recoring, the less stuff in between
the microphone and the sound card the better.


--
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 he double-m-eleven-double-zero at yahoo

The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?

In article writes:

6.02 volts.

Wrong. It's 2 dB over 1 volt. That's 1.26 volts.

6.02 volts would be +15.6 dBV






--
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 he double-m-eleven-double-zero at yahoo

S O'Neill wrote:
6.02 volts,

which was really, really wrong. Sorry. Everyone else got it right.

Powell wrote:

The specs on the card indicate a peak analog
input signal of +2dBV. What voltage does this
represent?


S O'Neill wrote:

6.02 volts.

Are you sure about that?


ulysses

Powell wrote:

Ok. Microphone pre-amp output is +22 dBu. What
voltage does this represent?

If the other correct posts are correct in saying that +2dBV is 1.26
volts, then +22dBV would be 12.6 volts. +22dBu is probably something
similar to +22dBV, but I'm too tired to open that can of worms. In any
event, this specification is probably the maximum output level before
clipping. Certainly your preamp is capable of putting out quieter
signals than that.

You might want/need to strap a terminating resistor across the output
of your RCA preamp in order to get flat frequency response.


ulysses

"Powell" wrote in message


Ok. Microphone pre-amp output is +22 dBu. What
voltage does this represent?

About 9.8 volts.

A mic pre that puts out this kind of voltage is obviously rather poorly
matched to an Audiophile 24/96. It can be made to work effectively a number
of ways, but like I keep saying, the Audiophile 24/96 is NOT designed to
work optimally in an audio production environment. That's why M-Audio makes
cards like the Delta 66, and Delta 1010. That's why most of their
competitors make cards with input and output levels that are like the Delta
66 and Delta 1010.

Yes, I'm sure it's wrong. I was thinking exactly backwards, and off a little
bit, but otherwise dead on. First misteak I ever made, too.

Justin Ulysses Morse wrote:

Are you sure about that?