Irritante brom/ruis uit DSP2000
Via de staudio mailinglist ben ik al meer te weten gekomen.
Het is dus (waarschijnlijk) geen groundloop o.i.d., maar een versterkt geluid van het interne computer geluid (ratelende hd, bewegende muis, etc.) Dit hoor ik ook duidelijk.
Hieronder enkele replies op mijn gestelde vraag:
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I know this noise. It is not an uncommon occurrence in DSP24/CPort
solutions (unfortunately). It is the one thing that ST Audio **really**
needs to overcome before they can really be taken seriously. Well,
since Steinberg has addressed the "snap, crackle and pop" issue with
Cubase SX 1.03, that is.
Now, this noise you speak of is not a (regular) ground loop noise, which
is a 50Hz (or 60Hz) hum. It is more like a highly amplified version of
the internal computer noise - you can hear the hard drive accessing, the
mouse moving, and it changes when the windows on the screen change (ie
when you open different parts of your sound recording program, and if
you open an Explorer window the noise also changes).
You *may* find that this noise stops when recording starts, or it may
continue as before - and become an unwanted part of your recording. You
may also notice that the noise changes drastically (from there to gone,
or from loud to quiet) when you make some changes to the External Links
routing.
We have a C-Port in our studio and occasionally it suffers from this
noise. A friend (E) has a C-Port in his studio, and he also suffers
from this noise. Another friend (G) has a C-Port in his studio, and he
suffers from this noise. Another friend (R) has 3 * C-Ports in his
studio PC, and he, too, suffers from this noise.
The three studios have vastly different equipment in them, and I have
heard this noise in ours, E's and G's studio. I am yet to make it to
R's place and hear his system. G's noise is **drastically** reduced
when he uses an external power supply for his C-Port, however this makes
absolutely no difference in our studio, nor in E's studio.
We are about to complete the final part of the rewiring of the (current)
studio (current before we do some "wall work" and have to rewire it
entirely). I'm going to pull the PC, C-Port, 01V and amplifier out of
the control room and sit them on a desk in the studio, and Mark and I
will throw both of our heads into this problem in an easier to access
environment. Once we get the system working 100% clean, we'll then
introduce the patchbay and other equipment item by item, testing each
step of the way.
I know that the location of the computer, C-Port, amplifier and
monitor/mouse/keyboard in relation to each other make no difference to
the noise levels.
Nor does ground-lifting the computer, amplifier, 01V and/or C-Port.
This noise situation is pissing me off enough that I'm contemplating
contacting ST Audio and Sound & Music (Australian importers) and asking
to have a couple of spare cards, units and cables sent so I can
determine if its a card, unit or cable issue - and I'll need these
cables (at least) to be sacrificial - I'll be chopping them up removing
Earths in different ways to see what happens.
I'd *really* like to sell a LOT more of these cards. From what work I
have done with the C-Port, I'm relatively impressed with them. There
were two major problems - the pops and crackles that almost every single
Nuendo and Cubase SX user was reporting (which seems to have been fixed
in Cubase SX 1.03), and the noise problem that is still unresolved.
This noise issue needs to be found and fixed. Whatever is causing it.
I'm willing to throw a few days of my time into it as long as ST Audio
and/or Sound & Music come to the party. I'll be performing a multi-OS
install (Win 98SE, 2000, XP (ACPI) and XP (AMP) so I can restore from
Ghost backups when necessary. This will definitely help with different
scenarios - using Cubase SX 1.03, Nuendo 1.6, Sonar and anything else I
can get my hands on for this test. I'd *like* to be able to get hold of
the latest beta drivers (even if they are not for public release) and
try them too.
If anyone has any suggestions, ideas, or any useful input on this
matter, it'd be appreciated.
--
Regards,
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>I know this noise. It is not an uncommon occurrence in DSP24/CPort
>solutions (unfortunately). It is the one thing that ST Audio **really**
>needs to overcome before they can really be taken seriously. Well,
>since Steinberg has addressed the "snap, crackle and pop" issue with
>Cubase SX 1.03, that is.
As you pointed out, since the C-Port box usually uses power direct from the PC, the noise can happen because of a dirty power supply. This has long been known but I'd forgot about it in this case because I simply haven't heard of such a case in quite a long while. I have never experienced that problem here, with the installation of several C-Ports. In Sten's case, it could very well be that the PSU is going bad and he might solve the problem by using an external AC adapter (preferably a heavy duty one of 1.5 or 2 amps). Maybe trying a new PC power supply would be best since that power is liable to affect the whole system anyway. I don't know of a simple way to test the PS to see how clean the power is but maybe just checking the voltages to see if they are stable and in spec would be a worthwhile start.
Pete Larson
Audience Digital Products
