Off Topic - Audiophile 2496 bad S/N ratio ?

[Terry Michael]

Moved house a year ago and my M-Audio Audiophile 2496 now is reading lows
signal-to-noise ratio's when monitoring in Wavelab 5. I used to get a
reading of around -87dB, but now I only get this figure when the audio ins
to the card are not connected to anything (mixer or compressor etc.).
Switching between 24 bit or 16 bit makes no difference to the meter reading
in Wavelab. Once I connect the sound card to my mixer the signal-to-noise
goes up to -75dB. Even an old Ensoniq PCI got this sort of figure? The
same setup was much quieter in my old home and have had to use different
cable runs/lengths to connect in the new home. Have just downloaded the
latest drives from the web but I doubt this will improve my signal to noise.
Could this be a earth loop or another interference-type problem? BTW I
pulled out my old Ensoniq PCI and after installing it the signal-to-noise on
this card is now running at -55dB so I think it might be a earth loop/hum or
something? I don't use balanced cables and just line level RCA's and phono
connections, but it used to be much quieter!!

[Laurence Payne]

So turn up the monitors and start plugging things in. (Well, turn
them down when actually plugging, THEN turn them up:-) When does the
noise appear? Yes, this could be an earth loop. Or just a bad cable.
Or an unfortunate cable routing.

This "different cable runs/lengths" worries me a little. Are you
trying to make things look tidy at the expense of keeping them close
together?

[Joel]

check out one of the newsgroups I frequent - alt.music.home-studio and
ask the question again. Another good place to ask would be at
www.soundclick.com in the community board called "Technical". I am in
both places daily.

By the way, my main production computer uses an M-Audio 2496 as well
but my production software differs from yours - I primarily use Sonar
Producer as my sequencer and Sibelius for sheet music software. I
also use Gigastudio and many different instrument sample sets
including Miroslav orchestral -- the low-end to Vienna Symphonic
(www.ilio.com).

If you want to check out some of the stuff I have written both vocal
and orchestral, check out www.soundclick.com/joelirwin. You can also
network with me at www.myspace.com/joelirwin.

Joel

[Gerry]

This is almost certainly one of two things:
(a) Earthloop;
(b) Extranious interference;

The former arises usually because there is a potential difference (ie
voltage difference) between two or more earth sounces on your gear. It can
be tested by cenrally earthing everything. The safest and simplest way to do
this is to plug all the gear used into a single socket (assuming the
amperage is limited enough to do this).

Somewhere I read a recommendation that the earth prong on the plug be
chopped off. Not a good idea unless you get off on feeling high voltage.

It is a really bad idea if you have 240 v mains and thr opposite of an idea
if you are using any 3phase high voltage stage gear. You could end in a
citation in the Darwin Awards.

The latter is most likely a localised source such as light dimmers and/or
fluorescent tubes nearby. The simplest test is to idolate them at the
source. That is to turn them off and keep them out of circuit. Depending on
the complexity you may need a good electrician for this too. Some of them
are physically immune from high voltage. Ohers are deceased.

In a nutshell if you can test safely then it is may be a very cheap way to
resolve it. If not then you need expert electrical help or you may need
expert medical help.

G. Mann.

[Bill Durham]

Terry Michael wrote:
> Moved house a year ago and my M-Audio Audiophile 2496 now is reading lows
> signal-to-noise ratio's when monitoring in Wavelab 5. I used to get a
> reading of around -87dB, but now I only get this figure when the audio ins
> to the card are not connected to anything (mixer or compressor etc.).
>

Terry,

If you get the -87dB reading with nothing plugged in, then the problem
doesn't exist in the sound card. You definetly have a ground problem.
You might go to an electrical distributor, I like Graybar..they are
everywhere in the US... and get an AC outlet analyzer. These are just
plugs that show if the outlet is wired properly.

BD

[Laurence Payne]

On Mon, 07 Aug 2006 10:05:30 -0400, Bill Durham
<billd...@attglobal.net> wrote:

>If you get the -87dB reading with nothing plugged in, then the problem
>doesn't exist in the sound card. You definetly have a ground problem.

There are causes of noise other than ground problems.