> On 2009-05-26, Nico Coesel <nico@puntnl.niks> wrote:
>> "miso@sushi.com" <miso@sushi.com> wrote:
>>
>>> On May 25, 2:21=A0pm, pantel...@gmail.com wrote:
>>>> On May 25, 10:10=A0pm, "m...@sushi.com" <m...@sushi.com> wrote:
>>>>
>>>>> You can always dual boot a windows PC.
>>>> It can be quite a challenge for a non Unix wizzard to start using
>>>> Linux,
>>>> especially command line tools like humfilter.
>>>> As humfitler is a a simple command line program,.
>>>> written in a simple C, and basically only
>>>> does wav file format input to wave file output,
>>>> it should be easily portable to DOS, and run in
>>>> a MSDOS window in for example XP.
>>>> Perhaps compile with the old djgpp compiler?
>>>> Several of my programs have been ported to DOS by people.
>>>> I am sure you can somehow send the wave output to a soundcard
>>>> even in MS software.
>>> It's been my experience that it is easier to compile software under
>>> Linux. The lack of compilers for windows is the issue. I assume to
>> Look for Mingw. Thats a GCC that works fine to compile software under
>> Windows. Still, more complex programs cannot be compiled easely
>> because of the Linux build tools.
>
> You can rin mingw on linux, or many of the build tools are portable
> to windows (modulo the limitations of the windows command-line).
Cygwin gives you a proper Linux command line under Windows.
--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
Reply by Jasen Betts●June 14, 20092009-06-14
On 2009-05-26, Nico Coesel <nico@puntnl.niks> wrote:
> "miso@sushi.com" <miso@sushi.com> wrote:
>
>>On May 25, 2:21=A0pm, pantel...@gmail.com wrote:
>>> On May 25, 10:10=A0pm, "m...@sushi.com" <m...@sushi.com> wrote:
>>>
>>> > You can always dual boot a windows PC.
>>>
>>> It can be quite a challenge for a non Unix wizzard to start using
>>> Linux,
>>> especially command line tools like humfilter.
>>> As humfitler is a a simple command line program,.
>>> written in a simple C, and basically only
>>> does wav file format input to wave file output,
>>> it should be easily portable to DOS, and run in
>>> a MSDOS window in for example XP.
>>> Perhaps compile with the old djgpp compiler?
>>> Several of my programs have been ported to DOS by people.
>>> I am sure you can somehow send the wave output to a soundcard
>>> even in MS software.
>>
>>It's been my experience that it is easier to compile software under
>>Linux. The lack of compilers for windows is the issue. I assume to
>
> Look for Mingw. Thats a GCC that works fine to compile software under
> Windows. Still, more complex programs cannot be compiled easely
> because of the Linux build tools.
You can rin mingw on linux, or many of the build tools are portable
to windows (modulo the limitations of the windows command-line).
Reply by Jasen Betts●June 14, 20092009-06-14
On 2009-05-25, panteltje@gmail.com <panteltje@gmail.com> wrote:
> On May 25, 10:10 pm, "m...@sushi.com" <m...@sushi.com> wrote:
>
>> You can always dual boot a windows PC.
>
> It can be quite a challenge for a non Unix wizzard to start using
> Linux,
> especially command line tools like humfilter.
> As humfitler is a a simple command line program,.
> written in a simple C, and basically only
> does wav file format input to wave file output,
> it should be easily portable to DOS, and run in
> a MSDOS window in for example XP.
> Perhaps compile with the old djgpp compiler?
Or compile with the current mingw compiler and run it on the
windows command-line
Reply by Eeyore●May 27, 20092009-05-27
Ben Bradley wrote:
> Here are my thoughts after reading the whole thread (I DID learn C
> 22 years ago - didn't make me rich, but it paid a lot more than
> cleaning toilets in recording studios, and probably even more than
> designing pro audio equipment).
>
> In sci.electronics.design and comp.dsp, On Thu, 21 May 2009 02:54:36
> +0100, Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
>
> >I am proposing to engage on a project regarding mains voltage 'purity'
> >(and absence of ) with regard to audible clicks and pops in high-end
> >professional and hi-fi audio equipment.
> >
> >Typical EMC filters operate in the RF band and are threfore no use to
> >filter audio 'in band' noise that can travel through transformer
> >interwinding capacitance etc.
> >
> >I have found some of the TI INA series that will with suitable
> >preconditioning, tolerate mains voltages and give excellent common-mode
> >etc rejection. So assembling a 'preamp' front end should be no problem.
>
> From what others posted, I'm thinking you might want to make
> several of these, to also measure things like the neutral voltage and
> the ground voltage (maybe referenced to your own ground stake you put
> in the ground outside the window or door, on the opposite side of the
> building where the main power comes in). Make these to withstand a
> kilovolt or more on the inputs (use several series resistors in each
> leg). That way you can see common-mode signals as well as
> differential.
>
>
> >What I will need to do however is to filter all the mains frequencies
> >and harmonics to a very large degree.
>
> You say elsewhere you want to see the results in "real time." I
> interpret that as "not having to wait 30 seconds for processing," that
> a half-second or two seconds might be acceptable.
>
> Others have said it, but I also see this as a PC application. A USB
> audio interface with four inputs should work (you probably want 24bit
> samples - if USB can't do 48/24 and 4 channels, you then use a desktop
> machine (or firewire, whatever), perhaps powered by a battery backup
> to insure line isolation, with a 4=channel or 8-channel card). Three
> inputs are for hot-to-neutral, neutral-to-your-ground,
> ground-to-your-ground, and the forth is the balanced output (with
> ground not connected!) of the mixer/console/UUT.
>
> You run this thing, and it samples data continuously. When the
> mixer has an output (or when there's an anomalous output on any of the
> other three inputs), the thing samples a few more cycles, then stops
> and does the filtering (on data that's a few cycles long), and shows
> the areas of interest, both with and without the 50/60Hz imposed on
> the hot/neutral input.
>
> This puts all the algorithms in a PC which has plenty of DSP
> horsepower thesedays, and also makes a good multichannel data
> recorder. I'm thinking you (or someone who knows C and PC code
> development) can get the Audacity source and modify it to do this (I
> don't know of the legalities and such of using the code in a
> commercial product, if you have to make the code you add open-source
> or what).
>
> And you just might want to have more inputs to look at, such as the
> main DC filtering caps of the console. This would show if the
> transient occurs at a time when the rectifiers are conducting.
Hi Ben,
just wanted to acknowledge the thought you put into this ( along with all
the other useful contributors ). I'm going to chew it over and get back
later.
Graham
--
due to the hugely increased level of spam please make the obvious adjustment
to my email address
Reply by miso...@sushi.com●May 26, 20092009-05-26
On May 26, 3:43�am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Mon, 25 May 2009 20:50:48 -0700 (PDT)) it happened
> "m...@sushi.com" <m...@sushi.com> wrote in
> <d946c8cd-b785-4f80-a7da-97d8bcce5...@p6g2000pre.googlegroups.com>:
>
> >It's been my experience that it is easier to compile software under
> >Linux. The lack of compilers for windows is the issue. �I assume to
> >use the soundcard in windows, you need to use some windows API, and
> >the documentation or lack thereof can be frustrating.
>
> humfilter does not use the sound card.
> It just creates a filtered wave file from a non-filtered wave file.
> there are plenty of free C compilers for MS win,
> including MS own one.
> But you can cross-compile on Linux too with for example DJ Delories
> djgpp as I pointed out.
> Or even native in MSDOS.
> I do not have it installed, but for 1000 Euro I could [make a DOS
> version of humfilter] :-)
> Else look here:
> �http://www.delorie.com/djgpp/
>
> Anyways, if you port my software (anybody) please keep to the GPL license
> conditions.
> I do no very actively pursue and search for GPL violations, but the FSF may
> torture you and send you to a jail in Cuba :-)
A bit off topic, but for those that want to do analysis on a wave
file, you can use sox to convert it into ascii. I've done this to put
sampled signals into spice as a PWL input. Obviously, you need to use
some scripting or write a small program to get the data in spice
format.
Reply by JosephKK●May 26, 20092009-05-26
On Fri, 22 May 2009 20:13:39 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>
>
>Nico Coesel wrote:
>
>> Eeyore wrote:
>> >Nils wrote:
>> >
>> >> After reading the discussion I wonder:
>> >>
>> >> Couldn't you simply connect a transformer to the mains, add a resistor
>> >> divider at the output to get the signal down and record the glitches?
>> >
>> >My front end will do all of that to get the levels right etc. The thing is,
>> >you don't seem to be able to see the glitches for the mains, we've already
>> >been looking. They must be quite small, or it's getting in via another
>>
>> Get a proper digital scope. Many scopes lower their samplerates so you
>> don't see short glitches. Lecroy is bad when it comes to this kind of
>> behaviour. What you need it peak detect.
>
>I agree but it's beyond our budget for this alone. By making dedicated kit of
>our own, designed specifically for this kind of job alone we can avoid that
>problem.
>
>Graham
Check leasing a good scope for 3 to 6 months. Might be worth it, then
again it might not.
Reply by Nobody●May 26, 20092009-05-26
On Tue, 26 May 2009 19:55:38 +0000, Nico Coesel wrote:
>>It's been my experience that it is easier to compile software under
>>Linux. The lack of compilers for windows is the issue. I assume to
>
> Look for Mingw. Thats a GCC that works fine to compile software under
> Windows. Still, more complex programs cannot be compiled easely
> because of the Linux build tools.
MSys (hosted on the MinGW site) provides make, a shell, and most of the
common text-processing tools (sed etc). This will allow a lot of Unix
projects to build with little or no modification.
>>use the soundcard in windows, you need to use some windows API, and
>>the documentation or lack thereof can be frustrating.
>On May 25, 2:21=A0pm, pantel...@gmail.com wrote:
>> On May 25, 10:10=A0pm, "m...@sushi.com" <m...@sushi.com> wrote:
>>
>> > You can always dual boot a windows PC.
>>
>> It can be quite a challenge for a non Unix wizzard to start using
>> Linux,
>> especially command line tools like humfilter.
>> As humfitler is a a simple command line program,.
>> written in a simple C, and basically only
>> does wav file format input to wave file output,
>> it should be easily portable to DOS, and run in
>> a MSDOS window in for example XP.
>> Perhaps compile with the old djgpp compiler?
>> Several of my programs have been ported to DOS by people.
>> I am sure you can somehow send the wave output to a soundcard
>> even in MS software.
>
>It's been my experience that it is easier to compile software under
>Linux. The lack of compilers for windows is the issue. I assume to
Look for Mingw. Thats a GCC that works fine to compile software under
Windows. Still, more complex programs cannot be compiled easely
because of the Linux build tools.
>use the soundcard in windows, you need to use some windows API, and
>the documentation or lack thereof can be frustrating.
Try to find a library that handles that for you.
--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
"If it doesn't fit, use a bigger hammer!"
--------------------------------------------------------------
Reply by Jan Panteltje●May 26, 20092009-05-26
On a sunny day (Mon, 25 May 2009 20:50:48 -0700 (PDT)) it happened
"miso@sushi.com" <miso@sushi.com> wrote in
<d946c8cd-b785-4f80-a7da-97d8bcce5d2f@p6g2000pre.googlegroups.com>:
>It's been my experience that it is easier to compile software under
>Linux. The lack of compilers for windows is the issue. I assume to
>use the soundcard in windows, you need to use some windows API, and
>the documentation or lack thereof can be frustrating.
humfilter does not use the sound card.
It just creates a filtered wave file from a non-filtered wave file.
there are plenty of free C compilers for MS win,
including MS own one.
But you can cross-compile on Linux too with for example DJ Delories
djgpp as I pointed out.
Or even native in MSDOS.
I do not have it installed, but for 1000 Euro I could [make a DOS
version of humfilter] :-)
Else look here:
http://www.delorie.com/djgpp/
Anyways, if you port my software (anybody) please keep to the GPL license
conditions.
I do no very actively pursue and search for GPL violations, but the FSF may
torture you and send you to a jail in Cuba :-)
Reply by JosephKK●May 26, 20092009-05-26
On Thu, 21 May 2009 21:48:23 -0700 (PDT), "miso@sushi.com"
<miso@sushi.com> wrote:
>On May 21, 2:04�pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
>wrote:
>> "m...@sushi.com" wrote:
>> > Eeyore <rabbitsfriendsandrelati...@hotmail.com> wrote:
>>
>> > > I am proposing to engage on a project regarding mains voltage 'purity'
>> > > (and absence of ) with regard to audible clicks and pops in high-end
>> > > professional and hi-fi audio equipment.
>>
>> > > Typical EMC filters operate in the RF band and are threfore no use to
>> > > filter audio 'in band' noise that can travel through transformer
>> > > interwinding capacitance etc.
>>
>> > > I have found some of the TI INA series that will with suitable
>> > > preconditioning, tolerate mains voltages and give excellent common-mode
>> > > etc rejection. So assembling a 'preamp' front end should be no problem.
>>
>> > > What I will need to do however is to filter all the mains frequencies
>> > > and harmonics to a very large degree.
>>
>> > > I imagine I would need for example to null 50 Hz +/- 2 Hz to ~ -100dB. I
>> > > have done only a little DSP ( I can't see it happening with analogue
>> > > filters ) and I don't even know where to begin with such a severe filter
>> > > without affecting the pass-band. Same will go for harmonics up to some
>> > > serious number.
>>
>> > > Can �anyone offer some advice as to algorithms ( number of cycles for
>> > > such a deep notch ) and even better, a readily available eval board upon
>> > > which it could be set up ? Remember I only need to 'hear' audio band, so
>> > > 44.1 or 48 kHz sampling should be OK esp given the oversampling ADCs
>> > > today.
>>
>> > I'd be more inclined to sample the AC by phase locking to it.
>>
>> Yes, sampling the mains fundamental would be neat. I don't think you'd even
>> need to be phase locked for simple notch filters.
>>
>> > Then you could easily create a comb filter to kill the power line
>> > fundamental
>> > and harmonics. This implies that you should use a 48kHz sample rate.
>>
>> Readily available.
>>
>> > I'm not sure you need any filtering prior to sampling given the
>> > dynamic range of ADCs these days.
>>
>> Agreed. Just a simple first order at some high frequency for luck probably.
>>
>> > If your spike is say 70dB down from the carrier (60/50 Hz mains), I can't
>> > believe it be significant to the
>> > power supply design.
>>
>> I wouldn't make ANY assumptions of that nature with today's high SNR audio !
>> I've seen some astonishing things.
>>
>> > Besides basic DSP filtering, you could use LMS to get rid of the
>> > fundamental. I suppose you could then LMS for each harmonic.
>>
>> Hadn't thought of LMS. Not looked at it in ages actually. You mean the
>> off-the-shelf package ? A bit pricey IIRC.
>>
>> Graham
>
>I programmed the LMS fit. For the fundamental, you just phase unwrap
>the sampled signal (presumably a sine) with an arcsin. The phase
>versus time plot should be series of points that would ideally be a
>straight line. If you fit a line to these points using LMS, the slope
>will indicate the LMS best fit to frequency. At the time, that was all
>I needed to do. But later I hacked a bit by creating a perfect sine
>wave using this LMS derived slope. I don't recall how I did the
>amplitude fit, but I think I didn't do LMS, but just ran some
>optimizer to vary the amplitude to make the difference between samples
>and the fitted sine wave go to a minimum. This is not a rigorous
>solution to the problem, but probably valid. Note I did this a few
>decades ago, so none of this is perfectly fresh in my mind, but the
>technique as I recall it is sound.
>
>As a hardware person, I think the phase locked sampling and comb
>filter would be the way to go. You probably would have to come up with
>a VXCO for the phase locked source. I hate all this windowing stuff.
>Synchronous sampling is much cleaner.
Sounds nearly sensible to the task, but does not address detecting the
difference of line disturbances very well.