Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.

--
*El nino made me do it

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

On 30/09/2019 15:05, Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.


Poor regulation or filtering, and that before any of the same is done in
the device. Maybe there is a ferrite choke you have omitted in your
rewiring?

Do you have a scope so you can look at the power rails?

Or just send it back (which will stop Brian screaming as it is probably
also doing something to his radio as well).

--
Adrian C

On 30/09/2019 15:05, Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

8 outlets is quite a lot. I have 5 and 6 port ones which are convenient for
going on holiday and have figure of 8 mains input sockets which I use
with an appropriate cable.

On 30/09/2019 15:05, Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.


Are all the outlets the same power rating? If not try one output that
can supply a higher current or, if possible, try your Toslink adapter on
its own in the 10 output power supply.

Does the total load of your USB devices exceed the total power available
from your USB power supply brick? For instance in may be rated for a
total of 50W which equates to 10 USB outputs at 1Amp. If you were using
all 10 outputs and a couple required, say, 2 Amps, then the other
outlets may only be able to supply 0.75 Amps or maybe when reaching
overload the regulation of the power starts failing

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.


Depending on the loads, you could be simply over loading it and it cant
regulate properly.

Unless by your €˜Happens with only it plugged in comment you mean you still
hear it with, say, just your amplifier and speakers and no USB devices.
That suggests a the beast has an inherent noise problem. Price doesnt
always equate to quality in terms of noise performance BTW- plasma TVs were
very expensive but very electrically noisy.


What make is it? I find Anker ones are generally pretty good. I dont know
if they do an 8 way one but certainly a 4 way.

Yes psu noise in analogue circuits is something I find I get on usb powered
devices. It seems to be on the earth as well. Some devices are more prone
than others.
It seems to be a factor of many tings particularly computer usb sockets.
Brian

--
----- --
This newsgroup posting comes to you directly from...
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Blind user, so no pictures please
Note this Signature is meaningless.!
"Dave Plowman (News)" wrote in message
...
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.

--
*El nino made me do it

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

No that will not happen. In many cases its tings like the behringer audio pc
interface that seem most prone. Short of getting inside and adding
decoupling, if that were possible, I ended up with a powered usb hum, and
found one particular socket was best. Of course then I wired in the TV and
found the video cable from the pc made it have what sounded like a 100hz
buzz all the time. sulk.
Brian

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

Blind user, so no pictures please
Note this Signature is meaningless.!
"Adrian Caspersz" wrote in message
...
On 30/09/2019 15:05, Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was
internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.


Poor regulation or filtering, and that before any of the same is done in
the device. Maybe there is a ferrite choke you have omitted in your
rewiring?

Do you have a scope so you can look at the power rails?

Or just send it back (which will stop Brian screaming as it is probably
also doing something to his radio as well).

--
Adrian C

In article ,
alan_m wrote:
On 30/09/2019 15:05, Dave Plowman (News) wrote:
Have a few devices in the AV setup which are USB 5v powered. To try and
keep things as neat as possible, all the mains to that are now IEC, as
that takes up less space than 13 amp.

So decided a USB power supply would be nice. One where the PS was internal
rather than a wall wart, and a main cable I could fit an IEC plug to.
Found one on Ebay with 8 outlets - not cheap either.

One of the things it would power being the a Toslink to phono adaptor -
TV audio into the amp. Which was just fine on its supplied 13 amp wall
wart. With a USB to USB lead.

I now get a noise like a distant burglar alarm on its output with the new
PS. ;-) Changed back to the original PS, OK.

Not a ground loop either. Happens with only it plugged in.


Are all the outlets the same power rating? If not try one output that
can supply a higher current or, if possible, try your Toslink adapter on
its own in the 10 output power supply.

The device is quite a posh one, and shows on its screen how much current
each outlet is taking. But I did say I'd tried it with only the Toslink
unit plugged into it with the same result.

Does the total load of your USB devices exceed the total power available
from your USB power supply brick? For instance in may be rated for a
total of 50W which equates to 10 USB outputs at 1Amp. If you were using
all 10 outputs and a couple required, say, 2 Amps, then the other
outlets may only be able to supply 0.75 Amps or maybe when reaching
overload the regulation of the power starts failing

--
*If I agreed with you, we'd both be wrong.

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

In article ,
Brian Reay wrote:
Not a ground loop either. Happens with only it plugged in.


Depending on the loads, you could be simply over loading it and it can‘t
regulate properly.

It would be some poor device with a large number of outlets which couldn't
supply the maximum USB can handle to only one of them

Unless by your �Happens with only it plugged in‘ comment you mean you
still hear it with, say, just your amplifier and speakers and no USB
devices. That suggests a the beast has an inherent noise problem. Price
doesn‘t always equate to quality in terms of noise performance BTW-
plasma TVs were very expensive but very electrically noisy.

Not quite sure what you mean. The noise comes from the combination of the
Toslink adaptor and that power supply. Even with the optical cable
unplugged. Change the PS and the noise goes.


What make is it? I find Anker ones are generally pretty good. I don‘t
know if they do an 8 way one but certainly a 4 way.

I'll look later.

--
*What do you call a dinosaur with an extensive vocabulary? A thesaurus.*

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

On 01/10/2019 10:57, Dave Plowman (News) wrote:

The device is quite a posh one, and shows on its screen how much current
each outlet is taking. But I did say I'd tried it with only the Toslink
unit plugged into it with the same result.

I'd hazard a guess here, that this device was intended to "charge"
things rather than provide "clean" DC for audio stuff...

In article ,
Lee wrote:
On 01/10/2019 10:57, Dave Plowman (News) wrote:

The device is quite a posh one, and shows on its screen how much
current each outlet is taking. But I did say I'd tried it with only
the Toslink unit plugged into it with the same result.

I'd hazard a guess here, that this device was intended to "charge"
things rather than provide "clean" DC for audio stuff...

Did wonder. Although the description didn't say that.

--
*I don't have a license to kill, but I do have a learner's permit.

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

In article ,
Andy Burns wrote:
there is no such thing as society

Irrelevant fatuous comment

made by Mrs T

Selectively quoted, of course ...

Do wish there was a bit more of that on here.

--
He who laughs last, thinks slowest*

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

On Tue, 01 Oct 2019 13:58:52 +0100, Dave Plowman (News) wrote:

Do wish there was a bit more of that on here.

In that case allow me to assist, Dave. This is from the item Andy linked
to...

Prime Minister Mrs. Thatcher:

"What is wrong with the deterioration? [mistranscription?] I think we
have gone through a period when too many children and people have been
given to understand €œI have a problem, it is the Government's job to cope
with it!€� or €œI have a problem, I will go and get a grant to cope with
it!€� €œI am homeless, the Government must house me!€� and so they are
casting their problems on society and who is society? There is no such
thing! There are individual men and women and [end p29] there are
families and no government can do anything except through people and
people look to themselves first. It is our duty to look after ourselves
and then also to help look after our neighbour and life is a reciprocal
business and people have got the entitlements too much in mind without
the obligations, because there is no such thing as an entitlement unless
someone has first met an obligation and it is, I think, one of the
tragedies in which many of the benefits we give, which were meant to
reassure people that if they were sick or ill there was a safety net and
there was help, that many of the benefits which were meant to help people
who were unfortunate€”€œIt is all right. We joined together and we have
these insurance schemes to look after it€�. That was the objective, but
somehow there are some people who have been manipulating the system and
so some of those help and benefits that were meant to say to people: €œAll
right, if you cannot get a job, you shall have a basic standard of
living!€� but when people come and say: €œBut what is the point of working?
I can get as much on the dole!€� You say: €œLook! It is not from the dole.
It is your neighbour who is supplying it and if you can earn your own
living then really you have a duty to do it and you will feel very much
better!€�

There is also something else I should say to them: €œIf that does not give
you a basic standard, you know, there are ways in which we top up the
standard. You can get your housing benefit.€�

But it went too far. If children have a problem, it is society that is at
fault. There is no such thing as society. [end p30] There is living
tapestry of men and women and people and the beauty of that tapestry and
the quality of our lives will depend upon how much each of us is prepared
to take responsibility for ourselves and each of us prepared to turn
round and help by our own efforts those who are unfortunate. And the
worst things we have in life, in my view, are where children who are a
great privilege and a trust€”they are the fundamental great trust, but
they do not ask to come into the world, we bring them into the world,
they are a miracle, there is nothing like the miracle of life€”we have
these little innocents and the worst crime in life is when those
children, who would naturally have the right to look to their parents for
help, for comfort, not only just for the food and shelter but for the
time, for the understanding, turn round and not only is that help not
forthcoming, but they get either neglect or worse than that, cruelty."



--
Leave first - THEN negotiate!

On Mon, 30 Sep 2019 15:05:11 +0100, Dave Plowman (News) wrote:

I now get a noise like a distant burglar alarm on its output with the
new PS. ;-)

Poor filtering on the output(s) of the new SMPSU and/or poor power
rail noise immunity of the adapter. Running te USB power cable
through a ferrite coore might be enough. Failing that an inline LC
filter, two ferrite cored tordial coils in each leg with a 0.1 uF
capacitor across the in and out. Coils need to made from fairly hefty
copper wire to avoid significan't volt drop. It does take much R at 1
A to drop the complete tolerance range of USB (5.25 V to 4.75 V).

Changed back to the original PS, OK.

Pragmatic solution: use that PSU.

--
Cheers
Dave.

In article ,
Cursitor Doom wrote:
Do wish there was a bit more of that on here.

In that case allow me to assist, Dave.

and so they are casting their problems on society and who is society?
There is no such thing!

There - I've done it for you. Selective quoting.

--
*Jokes about German sausage are the wurst.*

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