Whining on audio when computer connected to amp.

I have been trying to make my new computer integrate with my stereo system.
However even using a Behringer usb sound interface still produces a whine
and general hash low level to playback signals, though not noticed on the
recording if its transferred to cd and played normally. The question is that
as things are plugged into the usb the tone and loudness varies, so I
suspect its either the power supply or something inside the computer putting
out this noise. If I got a hub with a psu so that the sound unit could be
powered by that, do you think it would be better.
It is low level but you know how it is, once you heard it, you always hear
it.
Brian

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In article ,
Brian Gaff wrote:
I have been trying to make my new computer integrate with my stereo
system. However even using a Behringer usb sound interface still
produces a whine and general hash low level to playback signals, though
not noticed on the recording if its transferred to cd and played
normally. The question is that as things are plugged into the usb the
tone and loudness varies, so I suspect its either the power supply or
something inside the computer putting out this noise. If I got a hub
with a psu so that the sound unit could be powered by that, do you think
it would be better. It is low level but you know how it is, once you
heard it, you always hear it.

Pretty common with computers of all types. You usually have to add a
decent sound card to get a decent audio output at the end of the day.

--
*My wife and I had words. But I didn't get to use mine.

Dave Plowman London SW
To e-mail, change noise into sound.

I don't think its the quality of the card or whatever, its getting in on the
supply I think. The internal card is quite good but its ruined by being so
near all the nasty noise generating components. At least this device is made
by a good well known company and is remote but does use the 5v on the usb
for its power.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Dave Plowman (News)" wrote in message
...
In article ,
Brian Gaff wrote:
I have been trying to make my new computer integrate with my stereo
system. However even using a Behringer usb sound interface still
produces a whine and general hash low level to playback signals, though
not noticed on the recording if its transferred to cd and played
normally. The question is that as things are plugged into the usb the
tone and loudness varies, so I suspect its either the power supply or
something inside the computer putting out this noise. If I got a hub
with a psu so that the sound unit could be powered by that, do you think
it would be better. It is low level but you know how it is, once you
heard it, you always hear it.

Pretty common with computers of all types. You usually have to add a
decent sound card to get a decent audio output at the end of the day.

--
*My wife and I had words. But I didn't get to use mine.

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
wrote:
In article , Brian Gaff
wrote:
I have been trying to make my new computer integrate with my stereo
system. However even using a Behringer usb sound interface still
produces a whine and general hash low level to playback signals,
though not noticed on the recording if its transferred to cd and
played normally. The question is that as things are plugged into the
usb the tone and loudness varies, so I suspect its either the power
supply or something inside the computer putting out this noise. If I
got a hub with a psu so that the sound unit could be powered by that,
do you think it would be better. It is low level but you know how it
is, once you heard it, you always hear it.

Pretty common with computers of all types. You usually have to add a
decent sound card to get a decent audio output at the end of the day.

However that "sound card" can often be a USB one. They key is to either:

A) Ensrure a 'USB powered' device gets its power froma quiet, stable, PSU.

or

B) Use a decent USB audio device that has its own dedicated PSU which is
quiet and stable.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article ,
Brian Gaff wrote:
I don't think its the quality of the card or whatever, its getting in on
the supply I think. The internal card is quite good but its ruined by
being so near all the nasty noise generating components. At least this
device is made by a good well known company and is remote but does use
the 5v on the usb for its power.

I've found this on quite a few USB outlets where the end requirement is
decent audio, via a convertor. Not really sure of the reasons.

--
*How much deeper would the oceans be without sponges? *

Dave Plowman London SW
To e-mail, change noise into sound.

It is the quality of the 'card' as *well* as the PSU. The 'sound card'
should smooth its input power if the circuits inside would otherwise pick
fluctuations up. If it was made to draw power from USB the designers should
not be so clueless as to assume the power will be absolutely clean. But of
course, if you bought a cheap-as-chips one, they won't have had any
incientive to do much about it.

You don't say *which* "Behringer" device you're using. The cheap ones I
tested certainly needed a decent PSU to work OK. I tended to use an
externally powered hub bought from CPC. But in practice if you want to
avoid such problems you probably need a device with its own dedicated PSU.

Jim


In article , Brian Gaff
wrote:
I don't think its the quality of the card or whatever, its getting in on
the supply I think. The internal card is quite good but its ruined by
being so near all the nasty noise generating components. At least this
device is made by a good well known company and is remote but does use
the 5v on the usb for its power. Brian

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On 2016-04-10 08:43:14 +0000, Brian Gaff said:

I have been trying to make my new computer integrate with my stereo
system. However even using a Behringer usb sound interface still
produces a whine and general hash low level to playback signals,
though not noticed on the recording if its transferred to cd and played
normally. The question is that as things are plugged into the usb the
tone and loudness varies, so I suspect its either the power supply or
something inside the computer putting out this noise. If I got a hub
with a psu so that the sound unit could be powered by that, do you
think it would be better.
It is low level but you know how it is, once you heard it, you always hear it.
Brian

Perhaps an earth loop problem. I was able to remove a continuous
background whine from an M-Audio USB DAC by using transformers on the
output to break the earth link between the computer and amp. I believe
that there are also USB isolators to do the same on the digital side,
which would be better.

Arthur

--
real email arthur at bellacat dot com

In article ,
Jim Lesurf wrote:
Pretty common with computers of all types. You usually have to add a
decent sound card to get a decent audio output at the end of the day.

However that "sound card" can often be a USB one.

I was assuming it would be PCI, etc. Perhaps not possible on a laptop.

--
*The most common name in the world is Mohammed *

Dave Plowman London SW
To e-mail, change noise into sound.

Yes that was my thought as well. What is odd though is that it does not seem
to have the issue on the input side, only the output side. OK its not cheap
as chips, but its not the high end one either. Having tested a higher end
one it seemed no better to me, so....

I'll have a play around a bit with powered hubs.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Jim Lesurf" wrote in message
...
It is the quality of the 'card' as *well* as the PSU. The 'sound card'
should smooth its input power if the circuits inside would otherwise pick
fluctuations up. If it was made to draw power from USB the designers
should
not be so clueless as to assume the power will be absolutely clean. But of
course, if you bought a cheap-as-chips one, they won't have had any
incientive to do much about it.

You don't say *which* "Behringer" device you're using. The cheap ones I
tested certainly needed a decent PSU to work OK. I tended to use an
externally powered hub bought from CPC. But in practice if you want to
avoid such problems you probably need a device with its own dedicated PSU.

Jim


In article , Brian Gaff
wrote:
I don't think its the quality of the card or whatever, its getting in on
the supply I think. The internal card is quite good but its ruined by
being so near all the nasty noise generating components. At least this
device is made by a good well known company and is remote but does use
the 5v on the usb for its power. Brian

--
Please use the address on the audiomisc page if you wish to email me.
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

In article , Dave Plowman (News)
wrote:
In article , Jim Lesurf
wrote:
Pretty common with computers of all types. You usually have to add a
decent sound card to get a decent audio output at the end of the day.

However that "sound card" can often be a USB one.

I was assuming it would be PCI, etc. Perhaps not possible on a laptop.

My experience has been that when using USB-powered USB audio devices with
a laptop they are often quieter if the laptop is being powered from its
batteries. Connecting and using the laptop's charger/mains PSU causes
noises. I also found with an old laptop that HD accesses also generated
audible noises on the audio.

The conclusion is that typical USB-powered USB Audio devices don't do a
good job of rejecting power rail variations. So they benefit from using
something that supply clean power. I found that one particular type of USB
hub from CPC was the best from a variety, and have used those since. If I
can recall/find the part number, I'll say.

But beyond that if you want good performance you really need to look for a
device that has its own dedicated power supply independent of the USB
power. The drawbacks, of course, being cost and the need for then supplying
that power.

Goes with my experience in testing and developing pre-amplifiers. I found
there that the PSU arrangements were very important and need to be
developed with care.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html