Annoying high pitch sound

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outteh
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Re: Annoying high pitch sound

Post by outteh » Wed Jun 03, 2015 2:15 pm

The audiobox is designed for microphone or instrument level input, not line level. See page 4 of your user manual? Also just to add to the confusion:

Line Level

Much of our gear is said to be at Line level. Audio interfaces, mixers, effects boxes, synths, keyboard workstations, preamp outputs are generally all at line level. However, there are 2 standards, often referred to as +4 and -10. It used to be, over a decade ago, that "professional" gear was set to +4 and "consumer" gear was set to -10. This does not hold up as well as it did. Many pieces of consumer and professional gear today can be switched from -10 to +4 via a switch in the piece's firmware. But it is not always the case. And this is why you need to be careful.
When you plug a +4 output into a -10 input its very easy to overload the input and bring in noise. Likewise a -10 output into a +4 input seems a little faint, which makes one want to boost the volume and add noise that way. Often, you can make a mismatch work, but you will know its not ideal and that the integrity of the signal was blemished.
The practical application of this knowledge is as follows; if you know you have consumer -10 gear you want to use, but you also want to use better +4 gear, make sure your audio interface or mixer can handle both +4 and -10. A lot of DJ mixers and DJ audio interfaces will only take -10 impedance at line level. Unfortunately for the industry, DJ rigs tend to fall back on a standard of RCA cables at -10 impedance and unbalanced gear, which can be a problem rejecting ground loops, using long cables and driving a loud and clean signal to the amp and speakers.

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outteh
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Re: Annoying high pitch sound

Post by outteh » Thu Jun 04, 2015 6:46 pm

You will need something like this

http://www.sweetwater.com/store/detail/DTI

to correct had impedance mismatch between the line out on the Yamaha and the instrument in on the Audiobox.

You could also look into getting a new audio interface that accepts line level inputs. :D

clavguy
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Re: Annoying high pitch sound

Post by clavguy » Fri Jun 05, 2015 6:56 am

So... Latest update on this situation.

Like Tom said, not all audio interfaces are constructed alike. The Presonus AudioBox USB that I have had forever is one of them. It will NOT take "line" level inputs on the audio in inputs no matter how far down you turn the input gain although one of the reviewers on youtube said it would.
It takes "mic" level and "instrument" level such as passive guitars etc. but not "line" level like the output of my synth rack. That being said, I am in the process of testing the Steinberg UR22 interface. Both inputs will accept "line" level signals. There is a HI-Z push button that changes input number 2 to HI-Z for guitars and the such. But, only input 2. I tested this out and the noise I was hearing is virtually gone. I say virtually because I can barely hear it when I crank the gains all the way up to a point that everything would be distorted anyway. Annnnnd when I push the HI-Z button that awful noise comes right back on channel 2.
I am contemplating the Focusrite Scarlett 2i4 because it has a "line/instrument" selector switch on each input channel plus a push button to insert an extra 10dB pad in each. The only reason I am hesitating is because of latency issues. One reviewer said he was able to cut his latency in half by using ASIO4ALL drivers instead of the ASIO drivers that came with the interface.
I will start a new thread to ask about that.
So anyways... All this being said along with the transformer that Tom suggested, I think this case is closed King.
Now i just dated myself Sgt Preston :mrgreen:

CHeers
Pierre
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Mark Bliss
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Re: Annoying high pitch sound

Post by Mark Bliss » Fri Jun 05, 2015 9:38 am

Good catch on Toms part. I thought all but the cheapest one channel guitar interfaces had line input capability. I have never personally encountered a 2 channel box without.
But cool! On your way to a resolution. Lets hear some noise. 8)
Stay in tune, Mark

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AHornsby
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Re: Annoying high pitch sound

Post by AHornsby » Fri Jun 05, 2015 8:11 pm

AHornsby wrote:Do you have a "smart" meter?
clavguy wrote:What's that?
A "smart" meter is the new style electric meter being installed throughout the country, by the utility company. It uses microwave frequencies in order to send real time electrical usage data via wifi.
AHornsby wrote:If the computer you're using for Mixcaft is hooked up to the internet directly, you could try and disable the adapter temporarily and see if that doesn't make any difference.
clavguy wrote: It's on WiFi
You could still disable the adapter temporarily... right click network icon. Open network and sharing center. Left click Change adapter settings. Right click disable.

If your noise is still there then it is not the internet connection and you can re-enable the adapter.

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Pete Stobbs
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Re: Annoying high pitch sound

Post by Pete Stobbs » Sat Jun 06, 2015 2:44 am

Hope it does not take as long as this to sort out :roll:

Strange 'outer space' signal that baffled Australian scientists turns out to be microwave oven:

http://www.telegraph.co.uk/news/worldne ... -oven.html
Win 8.1
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Hughes & Kettner TubeMeister 5 head.
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https://soundcloud.com/toltec-jive

Ianpb
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Re: Annoying high pitch sound

Post by Ianpb » Sat Jun 06, 2015 7:35 pm

By "scratchy sound" I assume you mean something similar to static. I had the same problem through my new Yamaha MSP5 monitors, and it included noise when the mouse was moved. After spending hours checking cables and speaker selector switch box internals, I finally found the problem this evening. It is indeed a ground (or earth) loop. I discovered this when I tried disconnecting the ground (earth) in the plug of a spare mains lead that supplies one of the speakers. If such manufacturers' leads are sealed, as the ones are with my speakers, the alternative is to disconnect the ground (earth) from an extension lead and plug the offending units, eg. monitors, into that.

clavguy
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Re: Annoying high pitch sound

Post by clavguy » Sat Jun 06, 2015 10:06 pm

Ianpb wrote:By "scratchy sound" I assume you mean something similar to static. I had the same problem through my new Yamaha MSP5 monitors, and it included noise when the mouse was moved. After spending hours checking cables and speaker selector switch box internals, I finally found the problem this evening. It is indeed a ground (or earth) loop. I discovered this when I tried disconnecting the ground (earth) in the plug of a spare mains lead that supplies one of the speakers. If such manufacturers' leads are sealed, as the ones are with my speakers, the alternative is to disconnect the ground (earth) from an extension lead and plug the offending units, eg. monitors, into that.
Hi...
If you scroll back a few entries, you will see I posted a 6 second recording of the actual sound
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Ianpb
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Re: Annoying high pitch sound

Post by Ianpb » Sun Jun 07, 2015 5:46 am

clavguy wrote:Hi...
If you scroll back a few entries, you will see I posted a 6 second recording of the actual sound
The sound I had was of a lower pitch and more uneven, but I'm guessing that may be because I have a 50Hz mains supply rather than the 60Hz that you have. However, similar to what I suggested earlier, you should get an extension lead and disconnect the ground (earth) from the plug, and then, one by one, with the exception of your computer, connect your various components to it. I exclude the computer because, unlike the peripherals, it's not double insulated and, being the central unit, will also act as the common grounding component. This simple procedure will at least confirm whether the unwanted sound is due to a ground loop or not.

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Mark Bliss
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Re: Annoying high pitch sound

Post by Mark Bliss » Sun Jun 07, 2015 6:20 am

For the sake of curious interest and for anyone else who is interested, the discussed noise isnt anywhere near 50 or 60 Hz.
Noise.png
Noise.png (9.29 KiB) Viewed 3320 times
Stay in tune, Mark

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outteh
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Re: Annoying high pitch sound

Post by outteh » Sun Jun 07, 2015 7:29 am

There are distinct differences among the various electrical phenomenon. All electrical circuits inherently have noise, it's the nature of electricity. Components are built with efforts to reduce or eliminate the noise. Some are successful, some are not. In Pierre's case it was a mismatch of electrical signal that caused the noise, an impedance mismatch. In Ian's case it was a failure of one of the electrical components to properly work, the ground wire. Electrical line interernce, normally called 50/60 cycle hum, is the result of electricity passing through various components and wires ungrounded. :D
Last edited by outteh on Sun Jun 07, 2015 9:00 am, edited 1 time in total.

Ianpb
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Re: Annoying high pitch sound

Post by Ianpb » Sun Jun 07, 2015 8:53 am

Mark Bliss wrote:For the sake of curious interest and for anyone else who is interested, the discussed noise isnt anywhere near 50 or 60 Hz.
The effects of ground loop are not restricted to a pure 50Hz/60Hz hum. I've never experienced the phenomena before, so likewise expected a 50Hz hum, but the sound I experienced was much higher in the audio range, plus noise from the computer, eg. moving the mouse, opening programs, and running videos. Disconnecting the ground from my monitor speakers cured it.

clavguy
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Re: Annoying high pitch sound

Post by clavguy » Mon Jun 08, 2015 6:48 am

Ianpb wrote:By "scratchy sound" I assume you mean something similar to static. I had the same problem through my new Yamaha MSP5 monitors, and it included noise when the mouse was moved. After spending hours checking cables and speaker selector switch box internals, I finally found the problem this evening. It is indeed a ground (or earth) loop. I discovered this when I tried disconnecting the ground (earth) in the plug of a spare mains lead that supplies one of the speakers. If such manufacturers' leads are sealed, as the ones are with my speakers, the alternative is to disconnect the ground (earth) from an extension lead and plug the offending units, eg. monitors, into that.
Can I use a bunch of these to issolate stuff?

http://www.homedepot.com/p/Leviton-15-A ... 356839-_-N
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outteh
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Re: Annoying high pitch sound

Post by outteh » Mon Jun 08, 2015 7:15 am

All that plug will do is provide a ground for the circuit it's plugged into. May help but your going to find it difficult to find something to hook the green wire to. It's normally attached to the screw that holds in the wall plate on an electrical outlet. There's no guarantee that the outlet is properly installed and grounded sufficiently. But for $1.00, go or it.

clavguy
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Re: Annoying high pitch sound

Post by clavguy » Mon Jun 08, 2015 7:21 am

outteh wrote:All that plug will do is provide a ground for the circuit it's plugged into. May help but your going to find it difficult to find something to hook the green wire to. It's normally attached to the screw that holds in the wall plate on an electrical outlet. There's no guarantee that the outlet is properly installed and grounded sufficiently. But for $1.00, go or it.
Hi Tom... I don't think you are totally correct about that plug. If you look at it.. One plugs a 3-prong plug with the grounding leg into it. Then the other side only has the two conductors. I would not connect that little grounding lug to anything. Therefore,I would be isolating whatever device is plugged in to it...
Wouldn't I?
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