Soundcard only sounds good at low volume levels

[NYC Producer]

Hello,
The problem I'm having is that my soundcard only sounds good at low volume levels.
As I begin to raise the volume or turn the gain knob (on my mixer)I hear a terrible amount of humm.
This wouldn't bother me as much but I'm forced to keep my levels so low that the signal is bearly audible.
I'm not sure but I believe it's the mixer (or mixer settings) because I've had the same problem with 2 soundcards (a Terratec ewx 24/96 and the current delta 44)(could it be the pci slot?). The Mixer is a new Behringer Eurorack UB 1832fx-pro (I've read the manual in engilsh, spanish and french) and I've tried adjusting the input gain, using balanced and unbalanced monster cables, lowering the volume settings on the soundcard and switching between +4dbu and -10dbv.
Any suggestions would be greatly appreciated...

[Alan]

2 things,what are you plugging into the mixer,and what is your ground situation?Behringer mixers may not have the best s/n ratio,but they don't produce the type of hum you describe unless the power supply is faulty.

[This message has been edited by Alan (edited 08-16-2003).]

[knowdoubt]

Also, do you get the hum from the mixer when turning the levels up without a soundcard plugged in? How do you have Your I/O's configured between your mixer, recording source, soundcard I/O's & power amp?

[NYC Producer]

I have 2 keyboards, a drum machine and a mic.
I kind of managed to reduce some of the hum by connecting 2 1/4" plugs to the outputs of the delta (left and right)(and into 2 separate channels of the mixer) so now I can lower the volumes a bit but there's still some hum coming out of the mixer and into my cd recorder(the tape output of the mixer)-
You mentioned "ground situation" I'm not sure what I should be looking for , I have the mixer plugged into a surge protector and everything (keyboards, drum machine etc.)is on a big wire rack with all the cables running to the back.
I do hear the hum when the soundcard is not plugged in- but not as much.

Thanks for replying.

[knowdoubt]

Well it's quite possible you have a ground loop situation between the mixer/soundcard/drum machine/keyboards.
I would start trouble shooting by 1st physically isolating each component (make sure their cases don't have an electrical ground contact through direct physical contact or via shared metal rack or anything like that). Next, listen to the headphone out of the mixer with only one channel level & headphone level up. There should be no hum. If there's hum, the mixer or power supply is defective. If that's OK try a keyboard & see if you get plenty volume with acceptable noise level, then move on to the next piece of gear & on.

Basic troubleshooting rests on minimizing the number of variables/components interacting & tested at a time.

[macouno]

Also... always nice to check... You don't happen to have any dimmer switches for your lights on the same electrical section in your house as the studio equipment do you? They can cause quite some hum.

[bubba freaktree]

make music with just the mixer.
no hum? good

listen to audio right out of your soundcard into a stereo or something like that. no hum? good

then go back to current situation. hum?
means you have a poor interaction between your computer and your mixer setup. put all of your keyboards mixer, computer on one power outlet strip into one outlet. you can put your printer and monitor on another outlet.

then run audio into your mixer with no keyboards or drum machine. if audio is fine, then good. if you plug in a keyboard or drum machine and it starts humming, well look into vsti's :-)

[NYC Producer]

I'll try that,
have you heard of a "power conditioner"?
does this help?

[bubba freaktree]

yes, those things are good.
furman is the company for that stuff.

if it's a simple ground problem on one analog cable path, look into the Ebtech Hum Eliminator. Costs about $35.

to simplify what i said earlier. your hum/noise problem can only be one of three things:
1)your computer/soundcard
2)your mixer/sound modules
3)the signal path between 1 and 2

if everything sounds like hell, check the signal quality of your wall outlet. there could be a wiring fault coming in from the outlet. different parts of houses tend to be on different ciruits. so if you could lug some of your stuff to a completely different room and start plugging some things into different outlets, you could explore that variable too.

[NYC Producer]

Thank You to everyone for your help.
Update:
I ended up returning the mixer- it was either defective or had a very bad signal to noise ratio.
I eliminated most of the problem by going with a new Yamaha mixer (MG 16/4).
I purchased Studiolink cables ( they have arrows to demonstrate which way the signal should go and are high quality- has to do with accomodating balanced and unbalanced signals and grounding).
Notice I said most of the problem... I still have some hum but intend to purchase the "EbTech Hum Eliminator" , hopefully this will remedy the remaining noise.
Has anyone had any experience with this product?
Once again thank you very much to everyone that has lent their knowledge and expertise.

[wogg]

they have arrows to demonstrate which way the signal should go

I almost spit out my coffee!

[NYC Producer]

I was told by the tech at M-Audio and the sales rep at Musician's Friend that these are the best cables I can get. So I tried it- according to them one end is grounded and the other is not... or something like that.
It may sound rediculous to you but when you're desperate you'll try anything and everything.
If someone told me smearing baby crap on my mixer will get rid of the noise, I'd try it. Of course I'd research it first.
Enjoy your coffee.

[wogg]

Ok, a single sided grounding issue, that makes a bit more sence. Out of curiosity, do they recommend the shield ground be connected on the signal source or at the input side?

I did think it was funny right off the bat though. I've heard plenty of Hi-Fi people fall for the ol' the electrons flow better in this direction BS. I hope I didn't offend you.

[NYC Producer]

I FOUND THE SOLUTION!!!!
But before that let me respond:
I believe the gentleman said that the shielded ground had to be connected to the output of the device.
By the way, no offense taken.
GOD BLESS EVERYONE THAT HELPED ME.
I tried everything mentioned in this topic and nothing worked 100% ( I came close but not 100%), then I decided to take apart my PC because I heard that some Video Cards can create interference when placed too close to a soundcard - the hum remained.
But then all of a sudden I removed my Firewire card and BAMMM!!! the HUM
(from hell) went away immediately. Then I danced and sang for hours with joy! I made a few recordings and they were awesome. I haven't tried disabling it in the control panel but that might work as well- for temporary hum removal- so that you don't lose the use of your Firewire card.
I am not completely sure why this worked but I wanted to post the solution so that anyone in my situation would consider trying it.
Once again, Thanks.