15 Aug
2009
15 Aug
'09
10:21 p.m.
On Sat, Aug 15, 2009 at 11:37:25AM +0200, hermann wrote:
Am Freitag, den 14.08.2009, 12:59 -0700 schrieb Ken
Restivo:
AWESOME!!
All I needed to do was the following in order to get the sound I wanted:
--- a/autowah.cpp
+++ b/autowah.cpp
@@ -956,7 +956,7 @@ class mydsp : public dsp {
virtual void buildUserInterface(UI* interface) {
interface->openVerticalBox("crybaby");
interface->addCheckButton("on/off", &fcheckbox0);
- interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
10.0f, 0.1f);
+ interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
50.0f, 0.1f);
interface->addHorizontalSlider("level", &fslider1, 0.1f, 0.0f, 1.0f,
1.000000e-02f);
interface->addHorizontalSlider("wet/dry", &fslider2, 0.0f, -1.0f,
1.0f, 1.000000e-03f);
Most of the time I'll have it set between 30 and 40, but having the headroom up to 50
is nice.
Quick example here:
http://www.restivo.org/misc/wahtest2.ogg
Here come the ducks!
Yes, please, I'd love to have a LADSPA version. I think the GTK version did strange
things to my window manager (i.e. it's not following the mouse anymore).
THANKS AGAIN! I will be using this Friday and Saturday night, for sure.
-ken
On Tue, Jul 21, 2009 at 05:56:42PM +0200, Carlos
Sanchiavedraz wrote:
Hi
The crybaby(wah) from guitarix is the original crybaby from Professor
Julius O. Smith as he describes here:
http://ccrma.stanford.edu/realsimple/faust_strings/Adding_Wah_Pedal.html
It's included in the faust distribution and there you can find also a
description how to make it a auto wah.
http://faust.grame.fr/
Anyway, here is the auto wah version as standalone app attached
You can build it with
g++ -O3 `pkg-config --cflags --libs jack gtk+-2.0` autowah.cpp -o
autowah
If you like it and will get a ladspa version, send me a note, it's fast
done with faust and I have a Id free for it.
have fun
hermann Really good info; in fact some time ago I tried
to figure out how to
analize and reproduce in the digital realm a sound or fx.
But, as Ken, my skills in DSP and programming aren't that good to try
to help in such a deep way. I think I'd be more usefull in analysing
by ear or to contribute with some ideas.
However, what I could do is to provide some more data from a Wah pedal
(borrowed), along with Julien's. In fact, I was considering to buy one
some time ago, but I didn't decided nor what kind (Wah, Cry baby...)
Maybe this is a sign ;)
2009/7/21, Ken Restivo <ken(a)restivo.org>rg>:
> On Mon, Jul 20, 2009 at 11:51:07AM +0200, Fons Adriaensen wrote:
>> On Sun, Jul 19, 2009 at 08:10:47PM -0700, Ken Restivo wrote:
>>
>> > Just a quick update on the wah research.
>> >
>> > A friend owns a Dunlop "Jimi Hendrix Wah", which says it is the
>> > "Original Thomas Design", by which I assume they mean to claim
it's the
>> > same design as the Thomas Organ Wah, formerly Vox.
>> >
>> > This website's describes the frequency response as a lowpass with a
>> > resonant peak:
>> > http://www.geofex.com/Article_Folders/wahpedl/wahped.htm
>> >
>> > So here is what JAPA says it does (and I believe JAPA more than some
>> > random website):
>> >
>> > When fully closed, it's a bandpass, with a VERY high Q!
>> > http://restivo.org/misc/lowend-jimi.png
>> >
>> > But, wait, when I open it up, suddenly it becomes more like a highpass,
>> > but with a lot of resonance:
>> > http://restivo.org/misc/midrange-jimi.png
>> >
>> > When it's fully opened, it's definitely a highpass, but with a
helluva
>> > peak:
>> > http://restivo.org/misc/high-jimi.png
>> >
>> > So, not only is the opposite of what that article says, but it's also
>> > kind of non-linear. I'll poke around the various LADSPA plugins and
see
>> > if I can find something nearly like this.
>> >
>> > Another guitar-player friend has a different wah (IIRC, either a "Cry
>> > Baby", or a Morley), and I'll see if I can run his through this
and see
>> > what it comes up looking like.
>>
>>
>> AFAICS this is a resonant (which is not the same as bandpass) filter.
>> If the response near Fs/2 bcomes flat, that does not mean it is a
>> highpass.
>>
>> Remember that any digital filter is 'mirrored' to the other side
>> of Fs/2. Also the magnitude of the response must be continuous or
>> zero at all points (for finite order).
>>
>> The result of all this is that at Fs/2 the response must be either
>> zero or have a zero derivative, i.e. be horizontal.
>>
>> In a high order filter you can make the 'roundoff' region near
>> Fs/2 very small, but it's always there, unless the response is
>> zero at that frequency.
>>
>> You can probably get this type of response using the MOOG VCF
>> by taking the output at a different point in the algorithm.
>>
>> The MOOG VCF is 4th order, this is overkill as the analog
>> circuit is very likely to be just 2nd order.
>>
>
> Thanks. Alas, that seems like a very concise explanation, but I don't have
> the mathematical background to implement that.
>
> If someone feels like modifying the Moog VCF to make it a Vox/Thomas Wah,
> I'd be eternally grateful. But it's pretty clear I don't have the skills
to
> take this over the finish line.
>
I received a suggestion off-list to try the Guitarix plugins, which I did, and got very
good results from it:
http://restivo.org/projects/wah/high-jimi.png
http://restivo.org/projects/wah/guitarixcry-high.png
http://restivo.org/projects/wah/lowend-jimi.png
http://restivo.org/projects/wah/guitarixcry-low.png
http://restivo.org/projects/wah/midrange-jimi.png
http://restivo.org/projects/wah/guitarixcry-mid.png
Part of the difference in the plots is that I wasn't using the correct JAPA settings
for the plots of the actual "Jimi Hendrix Thomas" wah. The frequencies are
different, but that might just be because the Guitarix plugin sweeps higher and lower than
the Jimi pedal.
It sounds great. Now I'm either going to hack together an auto-wah via AMS or
something and an envelope follower, or build myself an Arduino pedal footcontroller.
Funky and fun.
-ken
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user 
16 Aug
16 Aug
5:27 a.m.
New subject: Wah update
Am Samstag, den 15.08.2009, 17:20 -0700 schrieb Ken Restivo:
On Sat, Aug 15, 2009 at 11:37:25AM +0200, hermann
wrote:
Hi
So here is the autowah as LADSPA plugin, mono, mapping 1.0 - 50.0 ,
Plugin Unique ID: 4069
I will lately include it to the guitarix package, but for now unpack it
and build it with:
g++ -fPIC -shared -O3 -Dmydsp=autowahdsp autowah.cpp -o autowah.so
Thanks goes to Julius O. Smith and Yann Orlary and all faust
contributors
have fun
hermann
Am Freitag, den 14.08.2009, 12:59 -0700 schrieb
Ken Restivo:
AWESOME!!
All I needed to do was the following in order to get the sound I wanted:
--- a/autowah.cpp
+++ b/autowah.cpp
@@ -956,7 +956,7 @@ class mydsp : public dsp {
virtual void buildUserInterface(UI* interface) {
interface->openVerticalBox("crybaby");
interface->addCheckButton("on/off", &fcheckbox0);
- interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
10.0f, 0.1f);
+ interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
50.0f, 0.1f);
interface->addHorizontalSlider("level", &fslider1, 0.1f, 0.0f, 1.0f,
1.000000e-02f);
interface->addHorizontalSlider("wet/dry", &fslider2, 0.0f, -1.0f,
1.0f, 1.000000e-03f);
Most of the time I'll have it set between 30 and 40, but having the headroom up to 50
is nice.
Quick example here:
http://www.restivo.org/misc/wahtest2.ogg
Here come the ducks!
Yes, please, I'd love to have a LADSPA version. I think the GTK version did strange
things to my window manager (i.e. it's not following the mouse anymore).
THANKS AGAIN! I will be using this Friday and Saturday night, for sure.
-ken On Tue, Jul 21, 2009 at 05:56:42PM +0200, Carlos
Sanchiavedraz wrote:
Hi
The crybaby(wah) from guitarix is the original crybaby from Professor
Julius O. Smith as he describes here:
http://ccrma.stanford.edu/realsimple/faust_strings/Adding_Wah_Pedal.html
It's included in the faust distribution and there you can find also a
description how to make it a auto wah.
http://faust.grame.fr/
Anyway, here is the auto wah version as standalone app attached
You can build it with
g++ -O3 `pkg-config --cflags --libs jack gtk+-2.0` autowah.cpp -o
autowah
If you like it and will get a ladspa version, send me a note, it's fast
done with faust and I have a Id free for it.
have fun
hermann Really good info; in fact some time ago I tried
to figure out how to
analize and reproduce in the digital realm a sound or fx.
But, as Ken, my skills in DSP and programming aren't that good to try
to help in such a deep way. I think I'd be more usefull in analysing
by ear or to contribute with some ideas.
However, what I could do is to provide some more data from a Wah pedal
(borrowed), along with Julien's. In fact, I was considering to buy one
some time ago, but I didn't decided nor what kind (Wah, Cry baby...)
Maybe this is a sign ;)
2009/7/21, Ken Restivo <ken(a)restivo.org>rg>:
> On Mon, Jul 20, 2009 at 11:51:07AM +0200, Fons Adriaensen wrote:
>> On Sun, Jul 19, 2009 at 08:10:47PM -0700, Ken Restivo wrote:
>>
>> > Just a quick update on the wah research.
>> >
>> > A friend owns a Dunlop "Jimi Hendrix Wah", which says it is the
>> > "Original Thomas Design", by which I assume they mean to claim
it's the
>> > same design as the Thomas Organ Wah, formerly Vox.
>> >
>> > This website's describes the frequency response as a lowpass with a
>> > resonant peak:
>> > http://www.geofex.com/Article_Folders/wahpedl/wahped.htm
>> >
>> > So here is what JAPA says it does (and I believe JAPA more than some
>> > random website):
>> >
>> > When fully closed, it's a bandpass, with a VERY high Q!
>> > http://restivo.org/misc/lowend-jimi.png
>> >
>> > But, wait, when I open it up, suddenly it becomes more like a highpass,
>> > but with a lot of resonance:
>> > http://restivo.org/misc/midrange-jimi.png
>> >
>> > When it's fully opened, it's definitely a highpass, but with a
helluva
>> > peak:
>> > http://restivo.org/misc/high-jimi.png
>> >
>> > So, not only is the opposite of what that article says, but it's also
>> > kind of non-linear. I'll poke around the various LADSPA plugins and
see
>> > if I can find something nearly like this.
>> >
>> > Another guitar-player friend has a different wah (IIRC, either a "Cry
>> > Baby", or a Morley), and I'll see if I can run his through this
and see
>> > what it comes up looking like.
>>
>>
>> AFAICS this is a resonant (which is not the same as bandpass) filter.
>> If the response near Fs/2 bcomes flat, that does not mean it is a
>> highpass.
>>
>> Remember that any digital filter is 'mirrored' to the other side
>> of Fs/2. Also the magnitude of the response must be continuous or
>> zero at all points (for finite order).
>>
>> The result of all this is that at Fs/2 the response must be either
>> zero or have a zero derivative, i.e. be horizontal.
>>
>> In a high order filter you can make the 'roundoff' region near
>> Fs/2 very small, but it's always there, unless the response is
>> zero at that frequency.
>>
>> You can probably get this type of response using the MOOG VCF
>> by taking the output at a different point in the algorithm.
>>
>> The MOOG VCF is 4th order, this is overkill as the analog
>> circuit is very likely to be just 2nd order.
>>
>
> Thanks. Alas, that seems like a very concise explanation, but I don't have
> the mathematical background to implement that.
>
> If someone feels like modifying the Moog VCF to make it a Vox/Thomas Wah,
> I'd be eternally grateful. But it's pretty clear I don't have the skills
to
> take this over the finish line.
>
I received a suggestion off-list to try the Guitarix plugins, which I did, and got very
good results from it:
http://restivo.org/projects/wah/high-jimi.png
http://restivo.org/projects/wah/guitarixcry-high.png
http://restivo.org/projects/wah/lowend-jimi.png
http://restivo.org/projects/wah/guitarixcry-low.png
http://restivo.org/projects/wah/midrange-jimi.png
http://restivo.org/projects/wah/guitarixcry-mid.png
Part of the difference in the plots is that I wasn't using the correct JAPA settings
for the plots of the actual "Jimi Hendrix Thomas" wah. The frequencies are
different, but that might just be because the Guitarix plugin sweeps higher and lower than
the Jimi pedal.
It sounds great. Now I'm either going to hack together an auto-wah via AMS or
something and an envelope follower, or build myself an Arduino pedal footcontroller.
Funky and fun.
-ken
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
17 Aug
17 Aug
4:41 a.m.
New subject: Wah update
On Sun, Aug 16, 2009 at 09:26:35AM +0200, hermann wrote:
Am Samstag, den 15.08.2009, 17:20 -0700 schrieb Ken
Restivo:
Thanks again!
I tried it with my full synth setup, and I know why they call it "Faust". The
deal with the devil that they've done, is it is very CPU-intensive.
This single little auto-wah plugin dominates more CPU power than a rack with 2 plugins
(CAPS VTS, TAP autopan). Even more than LinuxSampler!
Also, strangely, it uses no CPU, until I play something through it, then it demands a lot
of CPU and doesn't stop even if I stop putting sound through it.
I may try to use it this weekend, and hopefully won't have any problems. Thanks to
Ingo, I'm running all this crazy Linux Audio stuff right now, on an Atom EEE, and
recompiling LinuxSampler at the same time, and typing email and surfing the web.
-ken
On Sat, Aug 15, 2009 at 11:37:25AM +0200, hermann
wrote:
Hi
So here is the autowah as LADSPA plugin, mono, mapping 1.0 - 50.0 ,
Plugin Unique ID: 4069
I will lately include it to the guitarix package, but for now unpack it
and build it with:
g++ -fPIC -shared -O3 -Dmydsp=autowahdsp autowah.cpp -o autowah.so
Thanks goes to Julius O. Smith and Yann Orlary and all faust
contributors
have fun
hermann
Am Freitag, den 14.08.2009, 12:59 -0700 schrieb
Ken Restivo:
AWESOME!!
All I needed to do was the following in order to get the sound I wanted:
--- a/autowah.cpp
+++ b/autowah.cpp
@@ -956,7 +956,7 @@ class mydsp : public dsp {
virtual void buildUserInterface(UI* interface) {
interface->openVerticalBox("crybaby");
interface->addCheckButton("on/off", &fcheckbox0);
- interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
10.0f, 0.1f);
+ interface->addHorizontalSlider("Mapping", &fslider0, 1.0f, 1.0f,
50.0f, 0.1f);
interface->addHorizontalSlider("level", &fslider1, 0.1f, 0.0f, 1.0f,
1.000000e-02f);
interface->addHorizontalSlider("wet/dry", &fslider2, 0.0f, -1.0f,
1.0f, 1.000000e-03f);
Most of the time I'll have it set between 30 and 40, but having the headroom up to 50
is nice.
Quick example here:
http://www.restivo.org/misc/wahtest2.ogg
Here come the ducks!
Yes, please, I'd love to have a LADSPA version. I think the GTK version did strange
things to my window manager (i.e. it's not following the mouse anymore).
THANKS AGAIN! I will be using this Friday and Saturday night, for sure.
-ken On Tue, Jul 21, 2009 at 05:56:42PM +0200, Carlos
Sanchiavedraz wrote:
> Really good info; in fact some time ago I tried to figure out how to
> analize and reproduce in the digital realm a sound or fx.
>
> But, as Ken, my skills in DSP and programming aren't that good to try
> to help in such a deep way. I think I'd be more usefull in analysing
> by ear or to contribute with some ideas.
>
> However, what I could do is to provide some more data from a Wah pedal
> (borrowed), along with Julien's. In fact, I was considering to buy one
> some time ago, but I didn't decided nor what kind (Wah, Cry baby...)
> Maybe this is a sign ;)
>
> 2009/7/21, Ken Restivo <ken(a)restivo.org>rg>:
> > On Mon, Jul 20, 2009 at 11:51:07AM +0200, Fons Adriaensen wrote:
> >> On Sun, Jul 19, 2009 at 08:10:47PM -0700, Ken Restivo wrote:
> >>
> >> > Just a quick update on the wah research.
> >> >
> >> > A friend owns a Dunlop "Jimi Hendrix Wah", which says it is
the
> >> > "Original Thomas Design", by which I assume they mean to
claim it's the
> >> > same design as the Thomas Organ Wah, formerly Vox.
> >> >
> >> > This website's describes the frequency response as a lowpass with
a
> >> > resonant peak:
> >> > http://www.geofex.com/Article_Folders/wahpedl/wahped.htm
> >> >
> >> > So here is what JAPA says it does (and I believe JAPA more than some
> >> > random website):
> >> >
> >> > When fully closed, it's a bandpass, with a VERY high Q!
> >> > http://restivo.org/misc/lowend-jimi.png
> >> >
> >> > But, wait, when I open it up, suddenly it becomes more like a
highpass,
> >> > but with a lot of resonance:
> >> > http://restivo.org/misc/midrange-jimi.png
> >> >
> >> > When it's fully opened, it's definitely a highpass, but with a
helluva
> >> > peak:
> >> > http://restivo.org/misc/high-jimi.png
> >> >
> >> > So, not only is the opposite of what that article says, but it's
also
> >> > kind of non-linear. I'll poke around the various LADSPA plugins
and see
> >> > if I can find something nearly like this.
> >> >
> >> > Another guitar-player friend has a different wah (IIRC, either a
"Cry
> >> > Baby", or a Morley), and I'll see if I can run his through
this and see
> >> > what it comes up looking like.
> >>
> >>
> >> AFAICS this is a resonant (which is not the same as bandpass) filter.
> >> If the response near Fs/2 bcomes flat, that does not mean it is a
> >> highpass.
> >>
> >> Remember that any digital filter is 'mirrored' to the other side
> >> of Fs/2. Also the magnitude of the response must be continuous or
> >> zero at all points (for finite order).
> >>
> >> The result of all this is that at Fs/2 the response must be either
> >> zero or have a zero derivative, i.e. be horizontal.
> >>
> >> In a high order filter you can make the 'roundoff' region near
> >> Fs/2 very small, but it's always there, unless the response is
> >> zero at that frequency.
> >>
> >> You can probably get this type of response using the MOOG VCF
> >> by taking the output at a different point in the algorithm.
> >>
> >> The MOOG VCF is 4th order, this is overkill as the analog
> >> circuit is very likely to be just 2nd order.
> >>
> >
> > Thanks. Alas, that seems like a very concise explanation, but I don't have
> > the mathematical background to implement that.
> >
> > If someone feels like modifying the Moog VCF to make it a Vox/Thomas Wah,
> > I'd be eternally grateful. But it's pretty clear I don't have the
skills to
> > take this over the finish line.
> >
I received a suggestion off-list to try the Guitarix plugins, which I did, and got very
good results from it:
http://restivo.org/projects/wah/high-jimi.png
http://restivo.org/projects/wah/guitarixcry-high.png
http://restivo.org/projects/wah/lowend-jimi.png
http://restivo.org/projects/wah/guitarixcry-low.png
http://restivo.org/projects/wah/midrange-jimi.png
http://restivo.org/projects/wah/guitarixcry-mid.png
Part of the difference in the plots is that I wasn't using the correct JAPA settings
for the plots of the actual "Jimi Hendrix Thomas" wah. The frequencies are
different, but that might just be because the Guitarix plugin sweeps higher and lower than
the Jimi pedal.
It sounds great. Now I'm either going to hack together an auto-wah via AMS or
something and an envelope follower, or build myself an Arduino pedal footcontroller.
Funky and fun.
-ken
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
Hi
The crybaby(wah) from guitarix is the original crybaby from Professor
Julius O. Smith as he describes here:
http://ccrma.stanford.edu/realsimple/faust_strings/Adding_Wah_Pedal.html
It's included in the faust distribution and there you can find also a
description how to make it a auto wah.
http://faust.grame.fr/
Anyway, here is the auto wah version as standalone app attached
You can build it with
g++ -O3 `pkg-config --cflags --libs jack gtk+-2.0` autowah.cpp -o
autowah
If you like it and will get a ladspa version, send me a note, it's fast
done with faust and I have a Id free for it.
have fun
hermann 
4:46 a.m.
New subject: Wah update
Ken Restivo <ken(a)restivo.org> writes:
Also, strangely, it uses no CPU, until I play
something through it,
then it demands a lot of CPU and doesn't stop even if I stop putting
sound through it.
This sounds like denormalize problem. What CPU are you on? Does it help
if you supply constant low level noise to the input? By using the
noise from soundcard input for example.
--
Nedko Arnaudov <GnuPG KeyID: DE1716B0>
5:01 a.m.
New subject: Wah update
On Mon, Aug 17, 2009 at 09:46:06AM +0300, Nedko Arnaudov wrote:
Ken Restivo <ken(a)restivo.org> writes:
Interesting. The CPU is this:
http://restivo.org/projects/eee/cpu.txt
Once it starts using up CPU, putting sound through doesn't seem to make a difference.
It's like it hits a wall as soon as some sound goes in, and doesn't ever back off
again.
-ken
Also, strangely, it uses no CPU, until I play
something through it,
then it demands a lot of CPU and doesn't stop even if I stop putting
sound through it.
This sounds like denormalize problem. What CPU are you on? Does it help
if you supply constant low level noise to the input? By using the
noise from soundcard input for example.
5:26 a.m.
New subject: Wah update
Am Montag, den 17.08.2009, 00:00 -0700 schrieb Ken Restivo:
On Mon, Aug 17, 2009 at 09:46:06AM +0300, Nedko
Arnaudov wrote:
ups, have only check it with guitar, there you have always a small noise
input.
Build it with the -mfpmath=sse flag enable. That would help. Or add a
denormal protection to it .
@211
for (int i=0; i<count; i++) {
float S0[2];
float fTemp0 = input0[i];
- S0[0] = fTemp0;
+ S0[0] = fTemp0 + 1e-20;
Ken Restivo <ken(a)restivo.org> writes:
Interesting. The CPU is this:
http://restivo.org/projects/eee/cpu.txt
Once it starts using up CPU, putting sound through doesn't seem to make a difference.
It's like it hits a wall as soon as some sound goes in, and doesn't ever back off
again.
-ken Also, strangely, it uses no CPU, until I play
something through it,
then it demands a lot of CPU and doesn't stop even if I stop putting
sound through it.
This sounds like denormalize problem. What CPU are you on? Does it help
if you supply constant low level noise to the input? By using the
noise from soundcard input for example.
5623
days inactive
5625
days old
linux-audio-user@lists.linuxaudio.org
5 comments
3 participants
participants (3)
-
hermann -
Ken Restivo -
Nedko Arnaudov