Mbox noise problem

[technobreath]

Hey.

For a while now I've been having issues with my mbox. It's not much of a recording interface since it's only two channel, but I use it all the time practicing with my band and also on our gigs. So I use it for some voice (because my voice sound better with autotune and inflator hehe) and for a bunch of VSTinstruments.

On gigs and band practice I run it on a laptop when I can (dell inspiron6000 with upgraded ram and hd to max limits for that computer) but after my upgraded my laptop the damn shit won't recognize the midi interface drivers, so I am going nowhere with it. Need another format I would think. So I now run the whole thing on my studio PC.

And here is the problem - it may be that the same problem is while using the laptop, I can't really remember since it's a while I've used it on the laptop.

From the beginning. I use the built-in soundcard - realtek or something - for windows sounds etc. So when I power up the computer the mbox and m4u midi interface starts up ok. Noiseless. The problem begins when I somehow activiate the mbox driver somehow - example: start cubase. Problem is also there if I decide to let windows use the mbox and start up a movie in wmp or similar.

The problem is a high pitched noise - not very loud, but it's there in the background all the time as long as the driver is active in use. I can describe it as a high pitched fan noise from a too hot graphics card or something like that, only not that loud. What I'm trying to say, it blends with the fan noises from the computer, and you can hear it in the background in the monitors, but the problem becomes even more evident when I plug in my headset and isolates myself from outside noise. Then it's a pain!

I've been enduring it because I don't use it for anything really serious right now, as described, and also the thought of having to buy a new interface, but now I've had enough. The noise isn't recorded - I mean - if I mix down a track and play it on my stereo, it is fine... so there is something in the signal chain from computer to mbox outputs.

At first I thought it was maybe my shitty behringer mixer (I traded a car wash and polish for that mixer once upon a time ) or my monitor amplifier that had gone bad, but as I said, when I quit cubase the noise disappears.

It may be a simple solution but I have no idea what to do next.

The only thing I can think of right now that I haven't really tried yet, is to plug my headset directly into the mbox, instead of the behringer mixer. I'll try that and update you on the results as soon as I get home from work - yes I can write this at work .

I'll try to give you guys a complete list of computer specs in case that should ring a bell with someone:

CPU: AMD athlon64-X2 6000 or something like that - it's dual core with 3.0Ghz
MB: MSI K9N Platinum SLI
Graphics: ASUS something PCI-e x16 - nvidia chip.
RAM: 2GB of normal RAM 800mhz bus
HD: 320GB Samsung SATA2
PSU: Chieftec ATX 20Pin - with converter to 24Pin - or the other way around...
DVD RW: samsung about 2 years old.
All S-ata cabling is the ones that came with the motherboard.
No extra fans
I have a microsoft keyboard/mouse set wireless on usb - about 6 years old.
I also use usb to power my midi keyboard. can't remember the exact name but something with "Radium".

The headset is AKG about 100 USD when I bought it 6 years ago

The audio cables (with jacks) is soldered by myself. I know how to make quality cables and have soldered stuff since I was a little boy, and learned from experienced people, so that's not it. I'm using pro quality cable and plugs - neutrik.

USB cables I'm not all that sure about. I mean, they weren't the cheapest, but I didn't buy them from a cheap place either, so if it's quality cables, or it's just them raising the price to their standard I don't know. But if usb cables could be part of the problem, feel free to recommend me what to buy.

Can it be the interface that has gone bad after all these years. I've had it for like 5 years now, and I bought it used from a musician buddy who I know treated it very nice, and so have I. I actually bought the mbox and midi interface and the keyboard from the same guy at the same time. So everything is treated good. He only sold it because he didn't use it too much.

Right now I use my headset only since I had to get rid of the monitors, haven't got any room for it right now where I live. It's crap, but ok until we get our new (old) house where I'm building a studio these days in the basement Luckily I have an understanding wife who really encourages me to invest in music stuff . As long as we can afford it of course...

Between all this chit-chat I hope you guys understand what the problem is, and hopefully someone has a solution

Thanks for reading-patience, and thanks for any input

[jagcmos]

Sounds like it might be a minor ground loop problem.

Does the noise change when you move your mouse or move a window ?

Make sure the Behringer and the computer are plugged into the same electrical outlet.

You might want to get a audio isolation transformer and connect it between the mbox and the Behringer. This usually corrects the problem.

Link: Ground Loop Isolator - RadioShack.com

[technobreath]

OK, thanks for the tip. You might be right. And yes, the noise change slightly sometimes with mouse movement...

All my equipment is plugged into the same outlet, as I have 8 outlets mounted under my desk witch is attached to the same cuircut, The cuircut I'm using has no ground though... I could always run new wires to get a grounded outlet, but i'm not sure I wish to do that where I live now. too much effort. and it costs some too...

I've never used something like a isolation transformer, but can't a DI box do the same job? I can't believe I haven't yet tried using a couple of DI boxes in the signal chain, I will try that tonight!

thanks.

[jagcmos]

A DI box has a different input/output impedance while a audio isolation transformer has matching input/output impedances.

You could use one for a test, but I personally would purchase a proper unit.

I'm surprised that you're getting even worse noise problems using a non-grounded circuit.

[technobreath]

ok, but despite of the different impedance a DI box would act as a isolation transformer only not 1:1, or am I wrong? Because the difference in impedance shouldn't really matter - I would just have to use xlr between DI box and mixers preamp input and the different impedance shouldn't mean anything worse than me having to set some knobs over again... or?

Because I've got some DIs lying around not using it...

I also remember having a similar problem with a projector using a vga extender. That setup made a similar noise in the front of house system! We could not figure out what the heck was wrong with it, especially since me and a buddy rebuilt the whole electrical system and wiring and we know that it has the same ground potential. But something else made the system noisy, we couldn't figure it out, so as a solution we had to remove the ground connection from the projectors. Then it was dead quite as it should be on a 100 000 dollar front of house setup. But as you say it is odd that I get this problem when ground is not present... the only thing that could potentially ground my system is the ethernet connection wich goes from my computer to a linksys wrt54gl and to a speedtouch thompson adsl modem and that is hardwired the phone line.... so maybe...

If the DI box suggestion fails I'll try to ground the cuircut, Ill have to run extention cable from the kitchen . Then I will try to isolate the problem by removing ground from different components...

[jagcmos]

The DI boxes should work.

What I meant is that I'm suprised that you are not getting more noise than a faint whining while running in a room without a ground.

There's no way I would personally run any audio equipment in a room without a properly grounded electrical system, but that's just me.

[boo]

If you google "mbox whine" you'll see this is a known problem, although digidesign seems to deny it has anything to do with their hardware.
Mbox or Mbox 2 experiences whine or high pitched noise while in use.

[technobreath]

boo, i will check this out. thanks for the input.

(edit: I checked out the link, and it actually states to use TRS from the mbox output - it may seem very stupid, but I didn't think it was a balanced signal... is it? Someone told me that it aint... but if it is I will find my shovel in my garage, go out and dig a hole in the ground and bury myself!- so be careful answering hehe. I also need to get some ground cuircut in here)

jagcmos. Ok... Well, the only reason why I run my equipment without ground cuircut is because right now I live in a basement appartment with ground only in the kitchen and bathroom, so either I need to have an extention cable from those places into my "studio" or rewire the room. I could do both, and I can do both, but the rewire thing is too much effort, and I don't like cables over the floors . As I said earlier, I will set things right when I move into our new house wich is right now occupied by my grandmother , but there won't be long before she will move from her big house, and I can move in. In the meantime I am remodelling the whole basement in that house, and one room is gonna be my studio. Look forward to that. Since I do about everything but the plumming myself it won't cost that much either.

[Husky Band]

I get the whine when I use my mbox 2 with Reaper but none when I use it with Protools. It's an evil plot to force you to use Protools.

[jagcmos]

Put that shovel away. It looks like the outputs are unbalanced.
Link: Mbox 2
Click on specifications.

I'm suprised that they used unbalanced outputs. Poor engineering decision.

The article suggests using a "monster" digital cable...