I was looking to find a simple answer to this issue, which seems to afflict
any usb sound device I use to connect to an analogue source. I did try the
internal card also, but that suffers from swooshes and other weird noises
due to it being inside a busy computer one assumes.
In the majority of cases the while is constant, though can vary if other
things are going on in the machine.
it seems to only be on the output sockets, and the input both line level
seem pretty good. This does not seem logical to me, but I've been told in
the main its because of the earth return through the usb and the one through
the mains are different impedances effectively modulating the supply. I did
find a special psu that supposedly fixes this sort off thing with a breaker
in the earth in the us be cable supplying isolated power only down the
line.
However most of these seem to be several times the cost of the interface.

I did wonder about a powered hub, but have been told this will not work.

Brian

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

Blind user, so no pictures please!

On Sun, 12 Feb 2017 20:50:07 -0000, "Brian Gaff"
wrote:

I was looking to find a simple answer to this issue, which seems to afflict
any usb sound device I use to connect to an analogue source. I did try the
internal card also, but that suffers from swooshes and other weird noises
due to it being inside a busy computer one assumes.
In the majority of cases the while is constant, though can vary if other
things are going on in the machine.
it seems to only be on the output sockets, and the input both line level
seem pretty good. This does not seem logical to me, but I've been told in
the main its because of the earth return through the usb and the one through
the mains are different impedances effectively modulating the supply. I did
find a special psu that supposedly fixes this sort off thing with a breaker
in the earth in the us be cable supplying isolated power only down the
line.
However most of these seem to be several times the cost of the interface.

I did wonder about a powered hub, but have been told this will not work.

Brian

I've never come across this problem. Can you give more detail about
your system?

d

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Well its quite common if you look it up on google. The whine is like a 1khz
with lots of harmonics on it. The system is a pretty normal pc with a quad
core processor solid state drive etc. I have a Behringer fairly cheap
phono input output device that seems to have been used by many as its
quality is good considering its price. You will find derivations o f it
avaialable everywhere. It obviously is the computer that is the issue as
using it on some other machines one cannot hear this sound. My guess from
reading is the earth voltage drop issue which in effect has put some
internal modulation on the analogue circuits. It does seem odd though that
they seem to affect the output side more than the input side.
There is a huge great earth terminal on the unit but trying various
connections to different gear makes very little difference.
Brian

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

Blind user, so no pictures please!
"Don Pearce" wrote in message
...
On Sun, 12 Feb 2017 20:50:07 -0000, "Brian Gaff"
wrote:

I was looking to find a simple answer to this issue, which seems to
afflict
any usb sound device I use to connect to an analogue source. I did try the
internal card also, but that suffers from swooshes and other weird noises
due to it being inside a busy computer one assumes.
In the majority of cases the while is constant, though can vary if other
things are going on in the machine.
it seems to only be on the output sockets, and the input both line level
seem pretty good. This does not seem logical to me, but I've been told in
the main its because of the earth return through the usb and the one
through
the mains are different impedances effectively modulating the supply. I
did
find a special psu that supposedly fixes this sort off thing with a
breaker
in the earth in the us be cable supplying isolated power only down the
line.
However most of these seem to be several times the cost of the interface.

I did wonder about a powered hub, but have been told this will not work.

Brian

I've never come across this problem. Can you give more detail about
your system?

d

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Hi Brian,
You don't mention which unit you have, but I'm using a Behringer UCA202
feeding a home-brew headphone amp. There's no apparent background noise
at all. I'm using a quite good quality lead between the Behringer and the
amp to prevent noise being introduced here. I've not got any sort of
fancy power supply or earthing arrangement.

In article om, mick
wrote:
Hi Brian, You don't mention which unit you have, but I'm using a
Behringer UCA202 feeding a home-brew headphone amp. There's no apparent
background noise at all. I'm using a quite good quality lead between
the Behringer and the amp to prevent noise being introduced here. I've
not got any sort of fancy power supply or earthing arrangement.

Brian mentioned his having a ground terminal. The UCA202 I have doesn't
provide one of those. So he may have a variant that includes an RIAA
preamp.

However when I tested the 202 it seemed OK *provided* the power supply to
it via USB was reasonably good. Changing lead here didn't seem to make any
difference - by measurement or listening.

We'd probably need more specific details of what Brian is doing to take
this much further.

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

On 13/02/2017 15:26, Jim Lesurf wrote:
In article om, mick
wrote:
Hi Brian, You don't mention which unit you have, but I'm using a
Behringer UCA202 feeding a home-brew headphone amp. There's no apparent
background noise at all. I'm using a quite good quality lead between
the Behringer and the amp to prevent noise being introduced here. I've
not got any sort of fancy power supply or earthing arrangement.

Brian mentioned his having a ground terminal. The UCA202 I have doesn't
provide one of those. So he may have a variant that includes an RIAA
preamp.

The UFO202 has line/phono input and a ground terminal.

If using a laptop it can help to disconnect the power and do your work
on battery.
And also checking the earthing. One path to earth is better than none or
several.

--
Eiron.

On 02/13/2017 03:01 PM, mick wrote:
Hi Brian,
You don't mention which unit you have, but I'm using a Behringer UCA202
feeding a home-brew headphone amp. There's no apparent background noise
at all. I'm using a quite good quality lead between the Behringer and the
amp to prevent noise being introduced here. I've not got any sort of
fancy power supply or earthing arrangement.


I wonder if the OPs issue is an earth loop issue, perhaps combined with
switch mode PSU noise? I've had horrendous noise when feeding a laptop
or netbook to an amp. Run off battery and the problem goes away.
Adding audio isolation transformers also makes the problem go away.

I could have posted this anywhere in this thread, but here is a good
place. In your example of the headphone amp is it run from batteries or
from a floating, ie not earth referenced, PSU?

Pete

Well its one of that series certainly, read my reply to the last post for
more details.
Brian

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

Blind user, so no pictures please!
"Peter Chant" wrote in message
...
On 02/13/2017 03:01 PM, mick wrote:
Hi Brian,
You don't mention which unit you have, but I'm using a Behringer UCA202
feeding a home-brew headphone amp. There's no apparent background noise
at all. I'm using a quite good quality lead between the Behringer and the
amp to prevent noise being introduced here. I've not got any sort of
fancy power supply or earthing arrangement.


I wonder if the OPs issue is an earth loop issue, perhaps combined with
switch mode PSU noise? I've had horrendous noise when feeding a laptop
or netbook to an amp. Run off battery and the problem goes away.
Adding audio isolation transformers also makes the problem go away.

I could have posted this anywhere in this thread, but here is a good
place. In your example of the headphone amp is it run from batteries or
from a floating, ie not earth referenced, PSU?

Pete

In article , Don Pearce
wrote:
On Sun, 12 Feb 2017 20:50:07 -0000, "Brian Gaff"
wrote:

I was looking to find a simple answer to this issue, which seems to
afflict any usb sound device I use to connect to an analogue source. I
did try the internal card also, but that suffers from swooshes and
other weird noises due to it being inside a busy computer one assumes.
In the majority of cases the while is constant, though can vary if
other things are going on in the machine. it seems to only be on the
output sockets, and the input both line level seem pretty good. This
does not seem logical to me, but I've been told in the main its because
of the earth return through the usb and the one through the mains are
different impedances effectively modulating the supply. I did find a
special psu that supposedly fixes this sort off thing with a breaker in
the earth in the us be cable supplying isolated power only down the
line. However most of these seem to be several times the cost of the
interface.

I did wonder about a powered hub, but have been told this will not work.

Brian

I've never come across this problem. Can you give more detail about your
system?

IIRC Brian is using one of the cheap USB Audio devices that tend to pick up
any crap on their USB power line, etc.

No idea who told him an externally powered hub "will not work". I found
that a decent one could make a difference when using a 25 quid USB DAC/ADC.
As does buying a better ADC or DAC in the first place!

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