29 Apr
2014
29 Apr
'14
3:59 p.m.
LAC 2014 wil start in less than 48 hours, with
what looks like a fully charged program of papers,
workshops, installations and concerts.
For those interested in audio measurements, there
will a paper by Robin Gareus about audio metering
(in a production context), and yours truly will
present a workshop about audio measurements (i.e.
the more technical side).
The workshop will start with some essential theory
(no rocket science maths), followed by hands-on
practice.
If you attend the workshop you can bring your laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things. Make sure to have jaaa and
jnoisemeter installed in that case. The best audio
interfaces for this sort of thing are those having
fixed or at least exactly repeatable analog gains.
I'll also introduce some python extensions and code
I've been using to measure audio HW and SW. For this
you will need python, numpy, scipy and matplotlib.
I'm using python 3.4, but things should work with
2.7 as well.
See you in Karlsruhe !
[*] Internal audio interfaces are usually not worth
the effort. Also, we'll have an assortment of XLR,
TRS and RCA cables but no 3.5mm jacks !
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
29 Apr
29 Apr
5:57 p.m.
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
If you attend the workshop you can bring your laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25.
ciao,
robin
8:12 p.m.
On Tue, 2014-04-29 at 17:57 +0200, Robin Gareus wrote:
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
It's discussable if a calibration by averaged potentiometers will last
very long, but assumed this should work, take care of the used glue. Hot
glue is good to make SATA connections inside a case stable etc.,
especially because hot glue is easy to remove, but since hot glue tends
to be UV-sensitive and easy to remove, it seldom last very long outside
of a case. Loctite likely is the better glue, but likely the
potentiometer never can be readjusted anymore, if you use Loctite for
screw locking.
If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25.
8:17 p.m.
On Tue, 2014-04-29 at 20:12 +0200, Ralf Mardorf wrote:
On Tue, 2014-04-29 at 17:57 +0200, Robin Gareus wrote:
> On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
>
> > If you attend the workshop you can bring your laptop
> > and audio interface [*] and have it calibrated against
> > a precision RMS meter so you can later use it to
> > measure other things.
>
> very nice! Will there be pliers and hotglue or similar crazy-glue
^^^^^^^
Usually you need very expensive adjustment screwdrivers, like the once
from Bernstein, you unlikely can calibrate something, using tools made
of metal.
available so
that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25.
It's discussable if a calibration by averaged potentiometers will last
very long, but assumed this should work, take care of the used glue. Hot
glue is good to make SATA connections inside a case stable etc.,
especially because hot glue is easy to remove, but since hot glue tends
to be UV-sensitive and easy to remove, it seldom last very long outside
of a case. Loctite likely is the better glue, but likely the
potentiometer never can be readjusted anymore, if you use Loctite for
screw locking.
8:45 p.m.
On 04/29/2014 08:12 PM, Ralf Mardorf wrote:
On Tue, 2014-04-29 at 17:57 +0200, Robin Gareus wrote:
It only really needs to last until I return from LAC.
At home I can do proper soldering and also calibrate other soundcards
once I have a proper reference.
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
It's discussable if a calibration by averaged potentiometers will last
very long, If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25. Hot glue is good to make SATA connections inside a
case stable etc.,
especially because hot glue is easy to remove, but since hot glue
tends to be UV-sensitive and easy to remove, it seldom last very
long outside of a case. Loctite likely is the better glue, but likely
the potentiometer never can be readjusted anymore, if you use Loctite
for screw locking.
good points. Well, I'm open to suggestions.
best,
robin
9:12 p.m.
On Tue, 2014-04-29 at 20:45 +0200, Robin Gareus wrote:
On 04/29/2014 08:12 PM, Ralf Mardorf wrote:
I don't know if this does work, when using a normal pot. A narrow
wide/range, different materials, difference in temperature and it likely
never will go back to the original position. Using metal film resistors
or a spindle trim-pots are the better solution.
Btw. if you plan to use a soldering iron, don't forget some tool to
unsolder ;).
It's discussable if a calibration by averaged
potentiometers will last
very long,
It only really needs to last until I return from LAC.
8:27 p.m.
On Tue, Apr 29, 2014 at 05:57:31PM +0200, Robin Gareus wrote:
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
For a UA25 you'd need a soldering iron to remove the pots
and replace them by fixed resistors :-)
The older UA5 (which I will bring) has an advantage in having
line inputs (on the back) that bypass the mic preamp. They have
a gain control, but it's just a passive pot which you can safely
turn to maximum. All this was removed on later models to make
place for MIDI connectors...
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25.
8:41 p.m.
On 04/29/2014 08:27 PM, Fons Adriaensen wrote:
On Tue, Apr 29, 2014 at 05:57:31PM +0200, Robin Gareus
wrote:
Ok. So let me rephrase the question: Will there be a soldering-ion and a
multimeter around? Or something similar that will allow to determine the
value of the required fixed resistors. (I'm cc'ing lac(a)linuxaudio.org in
case the ZKM can provide)
A box with an assortment of resistors will be the easy part, I reckon.
ciao,
robin
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
For a UA25 you'd need a soldering iron to remove the pots
and replace them by fixed resistors :-) If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25.
8:57 p.m.
On Tue, Apr 29, 2014 at 08:41:14PM +0200, Robin Gareus wrote:
Ok. So let me rephrase the question: Will there be a
soldering-ion and a
multimeter around? Or something similar that will allow to determine the
value of the required fixed resistors.
The simple solution is calibrate at full gain, even if that is
too sensitive for practical use. Then depending on the circuit,
you could just remove the pot (if it is used as a divider), or
replace it by a fixed resistor of the same value.
A multiface is an excellent card for measurements (no pots at
all). Another good one is the RME RPM. It's easy to bypass the
RIAA preamps (just a few alsamixer commands), and the outputs
are *real* balanced (i.e. two signals with opposite polarity).
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
9:04 p.m.
On Tue, Apr 29, 2014 at 08:41:14PM +0200, Robin Gareus wrote:
Ok. So let me rephrase the question: Will there be a
soldering-ion and a
multimeter around? Or something similar that will allow to determine the
value of the required fixed resistors. (I'm cc'ing lac(a)linuxaudio.org in
case the ZKM can provide)
A box with an assortment of resistors will be the easy part, I reckon.
The meter that ZKM will provide is a level meter only, AFAIK it
doesn't measure resistors. But it should be possible to find a
digital multimeter.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
8:43 p.m.
On Tue, 29 Apr 2014 18:27:16 +0000
Fons Adriaensen <fons(a)linuxaudio.org> wrote:
On Tue, Apr 29, 2014 at 05:57:31PM +0200, Robin Gareus
wrote:
I've got an M-Audio 2496 card which has no pots at all. Unfortunately it
would be a bit difficult trying to stuff it into a laptop :)
Hmmm. I've long since lost the user guide. I wonder how accurate these
actually are.
--
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
For a UA25 you'd need a soldering iron to remove the pots
and replace them by fixed resistors :-)
The older UA5 (which I will bring) has an advantage in having
line inputs (on the back) that bypass the mic preamp. They have
a gain control, but it's just a passive pot which you can safely
turn to maximum. All this was removed on later models to make
place for MIDI connectors...
Ciao,
If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the soundcard in
question? I'm planning to bring a UA-25. 
9:47 p.m.
On Tue, 29 Apr 2014 18:27:16 +0000
Fons Adriaensen <fons(a)linuxaudio.org> wrote:
On Tue, Apr 29, 2014 at 05:57:31PM +0200, Robin Gareus
wrote:
I'd like to bring my UA25 as well, but sadly I won't be coming this
year.
Instead of key signing parties we well have interface calibration
parties. :)
I wish you all a ton of fun at the LAC.
Regards,
Philipp
On 04/29/2014 03:59 PM, Fons Adriaensen wrote:
For a UA25 you'd need a soldering iron to remove the pots
and replace them by fixed resistors :-)
The older UA5 (which I will bring) has an advantage in having
line inputs (on the back) that bypass the mic preamp. They have
a gain control, but it's just a passive pot which you can safely
turn to maximum. All this was removed on later models to make
place for MIDI connectors...
Ciao, If you attend the workshop you can bring your
laptop
and audio interface [*] and have it calibrated against
a precision RMS meter so you can later use it to
measure other things.
very nice! Will there be pliers and hotglue or similar crazy-glue
available so that one can permanently fix the dials of the
soundcard in question? I'm planning to bring a UA-25.
4057
days inactive
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linux-audio-user@lists.linuxaudio.org
11 comments
5 participants
participants (5)
-
Fons Adriaensen -
Philipp Überbacher -
Ralf Mardorf -
Robin Gareus -
Will Godfrey