ALSA for audio
 

On Thu, 14 Feb 2013 14:32:23 +0000 (GMT)
Jim Lesurf wrote:

I've now added another page at

http://www.audiomisc.co.uk/Linux/ALS...reSilence.html

which focusses more on how to set up audio playback as you prefer.

I have at least one more page in mind, but will try again to make my
mind get on to writing an article instead! :-)

Slainte,

Jim


Ok, I follow all that, especially as we have been through it! The 'Tip'
text has a couple of small typos, but that's easy to fix.
--
Davey.

ALSA for audio
 

In ,
Davey wrote:

On Thu, 14 Feb 2013 02:21:21 +0000 (UTC)
Martin Gregorie wrote:

Alternatively, you might want to look at using an Ion U-Record, just
under 30 squids from Amazon. Its a USB stereo ADC, accepts line-in or
MC pickup levels and is powered off the USB connection.

[Snip]

I had seen adverts. for Ion stuff, but was wary due to many bad reports
of their slide and negative copying devices; I just made my own, from
a couple of cardboard boxes and Sellotape, and have
successfully digitised hundreds of slides for a History Society.

Behringer also make this sort of thing. I think they have a good
reputation among audio people. I bought a UFO202 a few years ago; I
can't remember how much it cost, but I'm pretty sure it was less than
£30. I've never had any problems with it.

--
TH * http://www.realh.co.uk

ALSA for audio
 

In ,
Jim Lesurf wrote:

You may also find that the mic input clips 'line' level voltages since a
mic input may have a preamp stage which can't cope with such 'high' levels.
Any hardware gain adjustment may be after this stage. This, again, all
depends on the specific hardware in the box.

In general I'd be wary of the analogue stages of hardware in a normal
computer. Might be OK. But a dedicated special purpose external 'sound
card' may well give much better results.

From what I've read you're quite right to be wary of standard sound
cards or onboard audio. A few years ago one of the regulars on
uk.comp.homebuilt used to point out that a reference design for sound
cards had an over-severe clipping circuit on the line-in (not just mic)
which would clip at well under the usual maximum level. And this design
was used by the vast majority of sound cards.

--
TH * http://www.realh.co.uk

ALSA for audio
 

On Thu, 14 Feb 2013 15:06:05 +0000 (UTC)
Tony Houghton wrote:

In ,
Davey wrote:

On Thu, 14 Feb 2013 02:21:21 +0000 (UTC)
Martin Gregorie wrote:

Alternatively, you might want to look at using an Ion U-Record,
just under 30 squids from Amazon. Its a USB stereo ADC, accepts
line-in or MC pickup levels and is powered off the USB connection.

[Snip]

I had seen adverts. for Ion stuff, but was wary due to many bad
reports of their slide and negative copying devices; I just made my
own, from a couple of cardboard boxes and Sellotape, and have
successfully digitised hundreds of slides for a History Society.

Behringer also make this sort of thing. I think they have a good
reputation among audio people. I bought a UFO202 a few years ago; I
can't remember how much it cost, but I'm pretty sure it was less than
£30. I've never had any problems with it.

Sounds interesting. I see it for £30 or £46 !

I just tried to open Audacity on my laptop, and it fails, and of
course, I can't find what I see in any of the Help files.
I get:
"audacity: pcm_plug.c:388: snd_pcm_plug_change_channels: Assertion
`snd_pcm_format_linear(slv-format)' failed. Aborted"

I think I'll stop there, unless this means something to somebody! I did
the Reset Preferences procedure as described in the Wiki, but it made no
difference.
--
Davey.

ALSA for audio
 

In article , Davey
wrote:
On Thu, 14 Feb 2013 13:55:37 +0000 (GMT) Jim Lesurf
wrote:


I'd have to dig though my old mags and documents to be sure. But I'd
guess it uses DIN sockets and has a line sensitivity of about 500 -
100 mV. So would need some resistors to cope with modern line voltages
(circa 1V to 2V).


I would be using the Tape Recorder Input on the Goodmans. Physically, I
can get the signals there, after a bit of soldering. Interestingly, the
DIN socket from the dead donor cassette deck has a bunch of resistors on
the DIN socket board, but I can't see what colours the bands are, they
are hidden. At the moment. I have a DIN-DIN cable already, it's a matter
of getting the signal to it that requires the soldering and construction
of a connector. This is possible.

A possible complication is that the original DIN specification included
that the signal should be a *current* source. Not everyone was mad enough
to impliment that, and instead went for voltage. So you can easily find
items from the period that aren't compatable with others unless there are
some 'bodge' resistors in the circuit!

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

ALSA for audio
 

In article ,
Davey wrote:

http://www.audiomisc.co.uk/Linux/ALS...reSilence.html


Ok, I follow all that, especially as we have been through it! The 'Tip'
text has a couple of small typos, but that's easy to fix.

Situation Normal. :-) I'll check when I get a chance.

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

ALSA for audio
 

In article ,
Davey wrote:

I just tried to open Audacity on my laptop, and it fails, and of
course, I can't find what I see in any of the Help files.
I get:
"audacity: pcm_plug.c:388: snd_pcm_plug_change_channels: Assertion
`snd_pcm_format_linear(slv-format)' failed. Aborted"

I think I'll stop there, unless this means something to somebody! I did
the Reset Preferences procedure as described in the Wiki, but it made no
difference.

It certainly means something to Google, though what it means seems to be
something to do with the JACK audio subsystem which I have never used.
If it still means nothing to you then perhaps uninstalling anything
JACK-related may be a good idea.

Linux audio has so many different systems anyway that removing ones
you don't need can only help (says the man who once again has given up
with PulseAudio and uninstalled it, although this time Pulse lasted as
much as 14 months before getting its automagic settings into such an
irrecoverable twist that it was no longer usable).

Nick
--
"The Internet, a sort of ersatz counterfeit of real life"
-- Janet Street-Porter, BBC2, 19th March 1996

ALSA for audio
 

On Thu, 14 Feb 2013 22:18:37 +0000 (UTC)
Nick Leverton wrote:

In article ,
Davey wrote:

I just tried to open Audacity on my laptop, and it fails, and of
course, I can't find what I see in any of the Help files.
I get:
"audacity: pcm_plug.c:388: snd_pcm_plug_change_channels: Assertion
`snd_pcm_format_linear(slv-format)' failed. Aborted"

I think I'll stop there, unless this means something to somebody! I
did the Reset Preferences procedure as described in the Wiki, but it
made no difference.

It certainly means something to Google, though what it means seems to
be something to do with the JACK audio subsystem which I have never
used. If it still means nothing to you then perhaps uninstalling
anything JACK-related may be a good idea.

Indeed. I have no idea what Jack is, but it is there, in /usr/lib64.
But what happens otherwise if I remove it?

Linux audio has so many different systems anyway that removing ones
you don't need can only help (says the man who once again has given up
with PulseAudio and uninstalled it, although this time Pulse lasted as
much as 14 months before getting its automagic settings into such an
irrecoverable twist that it was no longer usable).

Nick

--
Davey.

ALSA for audio
 

On 14/02/13 22:56, Davey wrote:

Indeed. I have no idea what Jack is, but it is there, in /usr/lib64.
But what happens otherwise if I remove it?

If it came as a dependency, something might stop working by being
uninstalled. If it came as a recommended package, something obscure
might no longer work, but you might well not notice it unless you do
obscure things. Try removing it and check that it isn't going to take
anything else with it. If it is, then it was a dependency, and it's up
to you to decide whether you can live without whatever else is going to
be removed or cancel the removal.

Jack is handy for music production, as you can often use some of the
features of your sound card which might not be supported by ALSA alone.
e.g. some sound cards have more flexible routing than ALSA supports, so
you could do multitrack monitoring in a way which eliminates the latency
you would get if the monitor channel were subject to the same delay the
recorded signal is. It's a bit like having a patch panel, hence the
name. It's essential in a recording studio, not so common in home music
systems. It also helps to know how to use it, as if you don't you
probably aren't getting much benefit from it.

--
╔�╦�╦�����╦���╗
â•‘ â•‘ â•‘ â•‘ â•‘
╔�� ║ ║ ║ ║ ║ ╔��
╚���╩�╩�╩�╩�╩�� -- JimP.

ALSA for audio
 

In article , Jim Price
wrote:
On 14/02/13 22:56, Davey wrote:

Indeed. I have no idea what Jack is, but it is there, in /usr/lib64.
But what happens otherwise if I remove it?


Jack is handy for music production, as you can often use some of the
features of your sound card which might not be supported by ALSA alone.

I continue to wonder about that. I haven't ever use 'Jack'. Never needed
it, despite recording things as well as playing and processing them. But my
impression is that it has been developed as a 'user friendly' sic way to
do things which its creators *think* people "can't do" with ALSA.

However the "can't" may mean "don't know how" rather than "physically
impossible" - mainly, perhaps, because making sense of ALSA can be a real
struggle. And may involve hand-editing files, etc, which is hardly
user-friendly if people want to dump the old image of Linux = "Typing
arcane commands into terminals". Plus documentation that only makes sense
when you've hacked your way to a solution. ...erm IMHO.

Indeed, I keep feeling that people have invented and added extra "sound
systems" as an alternative to understanding and documenting (and making
programs to ease) doing this using ALSA.

The result now seems to be a pile of 'different' sound systems, which can
easily interfere with simple user choices that don't fit the auto-magical
assumptions of an install. Hence Jack, Pulse, etc, become a PITA for many
rather than a solution. And make some people feel it is a hopeless task to
do something as simply play music as they prefer.

So far as practical, I'd advise people to avoid Jack, Pulse, etc, as they
just complicate issues for basic uses. As far as I'm concerned, Pulse is a
virus. But as usual, YMMV. ;-

2p ended. :-)

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