Le 12/01/2010 10:52, Jim Lesurf a écrit :
In article , froggy
wrote:
Le 11/01/2010 10:55, Jim Lesurf a écrit :


Why not simply change to an outboard DAC like the DACMagic? That works
very well in my experience.


I tried plugging my Acer Aspire One 751H nettop into a dacmagic via the
usb connection using foobar & asio4all. The sound was absolutely vile!
It sounded like a gurgling 78rpm played on a distant AM radio. Am I
doing something wrong I ask myself?

Maybe you were listening to a net radio station of someone playing a 78.
:-) Can't tell as you don't say what source material you were using.

However you may need to check that the data is being sent reliably via USB.

With my ancient laptop I had to tweak some of the ALSA and Pulse settings
to avoid occasional breaks. But not had to do that with my new laptop.
However if you are using Windows I can't comment on any software tweaks.

FWIW It works well here from a Shuttle using Ubuntu. Details on the
audiomisc website.

I don't use the DACmagic via usb with my fairly new Acer 5738Z as that
works nicely via its optical spdif output using Xubuntu.

BTW For both the above I have a 60GB SSD fitted as the HD.

Slainte,

Jim


Thanks for your insight Jim.

I was listening to both flac and wav files ripped from CDs.
OS is Win XP3.
I wondered if Windows was corrupting the sound in anyway so I installed
Mandriva 2010 on a sdhc card, plugged it into the card reader and
restarted the computer on the card.
The problem persisted even under Linux (using Amarok and Rhythmbox)
I'm wondering if it isn't a hardware related problem.
Unfortunately there is no spdif output on the Aspire One 751H to fall
back on.....

Cheers.

--
Froggy


"Les cons ça ose tout, c'est même à ça qu'on les reconnaît."

Michel Audiard, "Les Tontons Flingueurs" (1963)

In article , froggy
wrote:
Le 12/01/2010 10:52, Jim Lesurf a écrit :
In article , froggy
[snips]

FWIW It works well here from a Shuttle using Ubuntu. Details on the
audiomisc website.

Thanks for your insight Jim.

I was listening to both flac and wav files ripped from CDs. OS is Win
XP3. I wondered if Windows was corrupting the sound in anyway so I
installed Mandriva 2010 on a sdhc card, plugged it into the card reader
and restarted the computer on the card. The problem persisted even under
Linux (using Amarok and Rhythmbox) I'm wondering if it isn't a hardware
related problem. Unfortunately there is no spdif output on the Aspire
One 751H to fall back on.....

One of the main things I insisted on when buying a new laptop was that it
had an optical output. Cost more to do so, but it does now work nicely and
gives bit perfect results at 44k.

Can't comment on Madriva 2010 as I've not tried it. Problem here is how
ALSA and/or Pulse are supplied by default and the details of any kernel
modules, etc.

However experiments with Ubuntu/Xubuntu make me think the critical thing
here is the specific settings for ALSA and/or Pulse.

There are some config settings for ALSA IIRC that set things like the size
of batches of data to send to the sound stream sink. Similarly, for Pulse.
This may matter for USB. At one point I did get occasional glitches and I
think I changed the batch details. But I can't now recall the details.

Unfortunately, soundcards can be a PITA because the producers often seem to
just do something that they think works 'OK' with the current Windows, even
if the result is rubbish in audio terms. So you may have a card where
no-one in the Linux community has been able to guess or reverse engineer
how to get it to co-operate.

Also you may find you are stuck with 'the wrong sample rate' with the
internal card as they just presumed that the OS would do a crude conversion
for you.

I think it likely that if you used Ubuntu 9.04 and setup Pulse as mentioned
on one of my webpages you would be able to get the DACMagic to work. But
I'm afraid I can't be 100 percent certain of that! And it can take some
furtling about as I know from experience! :-/

Should also mention that I think the situation has changed with Ubuntu
9.10, and I've not bothered to change to that as yet, so can't comment. May
be easier, may be harder. However Pulse should 'see' the USB DAC and let
you set it as the sound sink, then be able to 'see' any source you play and
direct that to the sink.

if you haven't already seen them, have a look at

http://www.audiomisc.co.uk/Linux/Sou...Computing.html

http://www.audiomisc.co.uk/Linux/Sou...stenAgain.html

The second one also has a link at the bottom to one of the useful pages for
settings up Ubuntu 9.04 so that it used Pulse nicely to feed the DACMagic.
There may be some other problem with your hardware, but that worked for me
OK.

Slainte,

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

As an adjunct to this thread. I noticed a strange thing today. The machine
with this noisy supply makes less noise, at least on the soundcard if you
take out the two ramsticks attached to its usb ports. This is particularly
noticable on the one plugged into the front port, presumably the wiring for
this is a lot longer.

So it sounds like the decoupling and conditioning of the supplies is even
more crap than at first thought by me!

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"bcoombes" bcoombes@orangedotnet wrote in message
...
Brian Gaff wrote:
Hi, you are indeed right, its one of those times when the fact that it
does what it says on the tin, is not enough. If I put a portable radio on
medium wave on a clear channel, when I switch the machine on, the same or
similar whining gurgling is heard. Other machines here have little
radiation at all.


Oh well, I have another one here somewhere!

Brian


Yeah I've heard that the Iranians jam BBC radio simply by powering up a
1000 low end Chinese PSU's.

--
Bill Coombes

Brian Gaff wrote:
As an adjunct to this thread. I noticed a strange thing today. The machine
with this noisy supply makes less noise, at least on the soundcard if you
take out the two ramsticks attached to its usb ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for ramdrives
on a pci card) AFAIK there's absolutely no way to attach ram via USB.. for
starters usb access is waaay too slow for that.. did you mean something else?

--
Bill Coombes

bcoombes wrote:
Brian Gaff wrote:
As an adjunct to this thread. I noticed a strange thing today. The
machine with this noisy supply makes less noise, at least on the
soundcard if you take out the two ramsticks attached to its usb ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for
ramdrives on a pci card) AFAIK there's absolutely no way to attach ram
via USB.. for starters usb access is waaay too slow for that.. did you
mean something else?


Sorry, I've read your post properly again [with brain engaged]. You removed two
chips *on the sound card* and that quietened it from a 'radio-active' point of
view? Hmm, interesting I've got a couple of cheap soundblaster cards lying
around, I'll have a look. I doubt if the chips you removed were 'ram' as such,
more likely to be the rom chips that are used to permanently hold a whole bunch
of stuff. [I'm not splitting hairs here, just replying to my own post really.]
It *is* very interesting that they quietened the card.

--
Bill Coombes

On Wed, 13 Jan 2010 15:41:39 +0000, bcoombes bcoombes@orangedotnet
wrote:

As an adjunct to this thread. I noticed a strange thing today. The machine
with this noisy supply makes less noise, at least on the soundcard if you
take out the two ramsticks attached to its usb ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for ramdrives
on a pci card) AFAIK there's absolutely no way to attach ram via USB.. for
starters usb access is waaay too slow for that.. did you mean something else?

You may be too clever for your own good! Plug a memory stick into a
modern Windows system, you get asked whether you want to use it as
system memory. Not quite RAM, but close.

On Wed, 13 Jan 2010 16:23:25 +0000, bcoombes bcoombes@orangedotnet
wrote:

As an adjunct to this thread. I noticed a strange thing today. The
machine with this noisy supply makes less noise, at least on the
soundcard if you take out the two ramsticks attached to its usb ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for
ramdrives on a pci card) AFAIK there's absolutely no way to attach ram
via USB.. for starters usb access is waaay too slow for that.. did you
mean something else?


Sorry, I've read your post properly again [with brain engaged]. You removed two
chips *on the sound card* and that quietened it from a 'radio-active' point of
view? Hmm, interesting I've got a couple of cheap soundblaster cards lying
around, I'll have a look. I doubt if the chips you removed were 'ram' as such,
more likely to be the rom chips that are used to permanently hold a whole bunch
of stuff. [I'm not splitting hairs here, just replying to my own po

You're being too clever AGAIN.

In article ,
bcoombes
bcoombes@orangedotnet wrote:
Brian Gaff wrote:
As an adjunct to this thread. I noticed a strange thing today. The
machine with this noisy supply makes less noise, at least on the
soundcard if you take out the two ramsticks attached to its usb
ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for
ramdrives on a pci card) AFAIK there's absolutely no way to attach ram
via USB.. for starters usb access is waaay too slow for that.. did you
mean something else?

Maybe Brian just means ram in the standard sense. i.e. they are random
access memory which you can read and write as you wish.

Although in principle of course, with *nix systems you can map out physical
devices however you chose, although it might be mad to treat an ordinary
USB stick as part of the main running memory in most cases. No idea if
Windows allows such things as I don't use it.

Slainte,

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

Laurence Payne wrote:
On Wed, 13 Jan 2010 15:41:39 +0000, bcoombes bcoombes@orangedotnet
wrote:

As an adjunct to this thread. I noticed a strange thing today. The machine
with this noisy supply makes less noise, at least on the soundcard if you
take out the two ramsticks attached to its usb ports.

Can't be, ram only goes in dedicated mobo slots. (or occasionally for ramdrives
on a pci card) AFAIK there's absolutely no way to attach ram via USB.. for
starters usb access is waaay too slow for that.. did you mean something else?

You may be too clever for your own good! Plug a memory stick into a
modern Windows system, you get asked whether you want to use it as
system memory. Not quite RAM, but close.

Ah yeah, M$'s wonderful 'ReadyBoost'. can make matters worse see
http://www.mpieters.com/2007/01/read...benchmark.html
It ain't equal to 'real' RAM but if you are trying to run Vista on very low RAM
(512k) it's just about better than nothing sometimes.
It is not however anything like the equivalent of adding mainboard RAM.


--
Bill Coombes

On Wed, 13 Jan 2010 16:56:20 +0000 (GMT), Jim Lesurf
wrote:

In article ,
bcoombes
bcoombes@orangedotnet wrote:
Brian Gaff wrote:
As an adjunct to this thread. I noticed a strange thing today. The
machine with this noisy supply makes less noise, at least on the
soundcard if you take out the two ramsticks attached to its usb
ports.


Can't be, ram only goes in dedicated mobo slots. (or occasionally for
ramdrives on a pci card) AFAIK there's absolutely no way to attach ram
via USB.. for starters usb access is waaay too slow for that.. did you
mean something else?

Maybe Brian just means ram in the standard sense. i.e. they are random
access memory which you can read and write as you wish.

Although in principle of course, with *nix systems you can map out physical
devices however you chose, although it might be mad to treat an ordinary
USB stick as part of the main running memory in most cases. No idea if
Windows allows such things as I don't use it.

Slainte,

Jim

If you plug a USB stick into a Vista machine it will ask you if you
want to use it as RAM for the machine. I'm not sure what it then does
with it - whether it treats it the same as the RAM on the motherboard,
or makes a sort of fast ramdisk with it. Most likely it uses it as a
swap area.

d