On July 18, 2010 03:57:06 pm Ralf Mardorf wrote:
> A lot of kids wish to have a kill switch for their guitars.
> A kill switch is a short circuit, to 'stop' the audio signal.
>
> I'm not fine with this solution, but the kids argue, that e.g. an
> interruption does cause unwanted noise, especially for over drive
> sounds. IMO even using opto-electronics won't solve the issue, because
> the noise of the transistor overdrive effect still would be hearable,
> while for a short circuit there is silence.
>
> Has anybody an idea to solve this without a short circuit?
>
> I'm really not a fan of short circuits. Note, it's not possible to do an
> interrupt all the times behind the latest noise generator and even an
> interrupt could cause noise itself, while a short circuit indeed is a
> good way to cancel sound.
If you don't like short circuiting the mics, just switch the output jack
hot lead between ground and the volume pot(s).
Connecting the output to ground is the same as turning the volume down.
There is no need to short the mics...
On 19.07.2010 08:30, Tim E. Real wrote:
> If you play a Gibson you can set the neck pickup volume to zero and
> the bridge pickup volume to full and then toggle the pickup switch,
> rapidly if desired, like Eddie van Halen on You Really Got Me.
> Tim.
Tom Morello gets real creative with his guirar, and uses this technique
alot. He also unplugs his guitar to make the pedals and amps make noise
(oscillate), and controls the noise with his wah pedal and by touching
the tip of the plug to the guitar bridge (which is grounded). Good
demonstration of how just cutting the signal lead can cause lots of
noise, while a short will be more or less silent :)
-Sakari-
Hi all,
I've just released a beta of a modular synthesis library using Jack2,
with a Ruby module. See http://ebuswell.github.com/Cshellsynth/
There's no mailing list for the project yet, but feel free to email me
directly if you have questions/comments/concerns.
Enjoy!
Evan
Hello all,
Early this week one of the three 'rendering' PCs of the WFS
system in the Sala Bianca failed. It just appeared completely
dead and didn't even try to boot when the power button was
pressed, but the standby power (for the network interface)
was available.
I suspected the power supply, so ordered a new one which
arrived two days ago. Installed it and things worked again.
But now comes the interesting part. While installing the new
PS, I also disconnected the wires to the power button, and
to test I just used a screwdriver to short the two pins that
normally connect to it. But when I reconnected the power button
the PC switched off after a few seconds. So it seemed as if the
power button was permanently being pressed. I again installed
the old PS, and things worked as long as the power button was
not connected.
Measuring the power button switch with a multimeter showed
an unstable resistance value of between 1 and 3k while it
was not pressed. So I removed the thing, which turned out
to be a cheap miniature switch, a little cube of around 8
mm size. I opened and disassembled it, and noticed that the
contacts had some black dirt on them. Cleaned with aceton
and reassembled, and things worked perfectly again.
What I don't understand is how the contacts got so dirty.
If a resistance of a few kOhm is enough to make it look
as a closed contact then it can't be handling large currents,
so there should not be any arcing. And the construction of
the thing is such that it is virtually closed, no dust or
whatever could ever creep in.
Still it's quite sobering that this cheap 0.30 Euro thing
was capable of bringing down a 1600 Euro workstation...
Who would suspect a switch to fail in this way ?
Ciao,
--
Je veux que la mort me trouve plantant mes choux, mais
nonchalant d’elle, et encore plus de mon jardin imparfait.
(Michel de Montaigne)
Without running JACK and with running JACK -p2048 44.1Khz and 96KHz,
without HR timer enabled and with HR timer enabled ALSA MIDI used to
make a thru connection was always ok when playing live, not only for the
PCI MIDI, but even for USB MIDI.
When playing the recordings from my last test by Qtractor, there wasn't
the issue anymore that FluidSynth and the internal Linux recorded
FluidSynth sometimes were out of sync. The MIDI and the audio track were
always in sync. I only tested it with system timer.
Anyway, there definitive is jitter for the recorded FluidSynth. It's
inaudible jitter, resp. it is audible when loop playing, because some
beats are played to early, because of jitter with negative delay. So
it's not an issue of bad timing, but because of notes that shouldn't be
played, when loop playing. It's still a recording from the last test,
not from today (note, I'm not writing about the hw MIDI at the moment).
There must have been something bad, that is ok today. I wondered myself,
because I never had this issues before.
I didn't test MIDI jitter for hw MIDI today. Anyway, ALSA MIDI for MIDI
thru is ok and also Qtractor always plays the MIDI and audio track in
sync.
For the important jitter tests I'll switch back to 64 Studio 3.0-beta3,
there might be something broken for 64 Studio 3.3 alpha or it was just
bad luck, anyway at least for FluidSynth with 3.0-beta3 there never were
issues.
Over the weekend I had no time to test MIDI as it was planned. It likely
will be the same for the next days.
Again there's hope that PCI MIDI jitter will be inaudible. Because even
the USB MIDI was ok for live playing, I suspect that the jitter for the
recordings is not regarding to ALSA MIDI. I wish I would have the time
to do some recordings right now.
Hi,
AFAIK Lennart and some other Red Hat devs, where talking about the Linux
Plumbers Conference at LAC2010, telling why it would be good if people from
the linuxaudio world would join that conference and why it could improve the
state of linuxaudio in the Linux environment.
Here is a call for papers:
http://www.linuxplumbersconf.org/2010/06/03/linux-plumbers-conference-call-…
\r
Here is the setup i'm looking to do:
midi master -> special program
ddr pad -> special program
special program -> hydrogen
I've got a hardware midi device controlling the master tempo. aseqdump shows
the tempo messages x times a second.
I want to either find or make a program so I can use a ddr pad (usb gamepad)
and assign different timed midi patterns to the buttons, so for example:
if the program is configured for 4/4 time, when I hold down or toggle a
button
if note 36 is a bass drum and 41 is a snare then you'd have a basic drum and
snare beat when both buttons are held down or toggled, of course i'd like to
be able to have multiple patterns bound per button as well
button one is set to play a quarter note midi note 36, then rest for the
remaining 3 beats
1 - 36,quarter|rest,quarter|36,quarter|rest,quarter
2 -
41,eighth|rest,eighth|41,eighth|rest,eighth|41,eighth|rest,eighth|41,eighth|rest,eighth
Each pattern would describe one measure, and the flow of a live solo
performance could easily be changed on the fly, leaving hands free to play
guitar.
Anything out there like this, and I just don't know about it?
If I don't find anything I want to hack something together, so a primer on
midi tempo sync, and how to program with it would be appreciated.
Thanks,
Nathanael
On Fri, Jul 16, 2010 at 5:27 AM, Geoff King <gsking1(a)gmail.com> wrote:
> Niels, Thank you for taking the time to work on improving Envy24Ctl.
> I tried your patch for the peaks and it seemed to work fine for me. Â I
> can't comment on the code (as I'm much more musician than programmer),
> but had no problem patching and installing. Â Looking forward to trying
> this new patch and whatever else you come up with. Geoff
Geoff -- thank you for trying out the patch! (And, OT, thanks for
working w/ Rui to help fix
http://sourceforge.net/tracker/?func=detail&atid=733076&aid=3021645&group_i…
:: "help fix qtractor crash on bus changing/configuration (3021645)" --
Envy24 and multichannel qtractor users, yes, it's time for a "svn up" ).
FYI, to try out the new levelmeters "easy", if you're running Fedora
x86_64, use the "envy24control" binary directly, or drop the
levelmeters.c file into your build:
http://nielsmayer.com/npm/Efficient-Meters-Envy24Control.tgz
( for details http://nielsmayer.com/npm/Efficient-Meters-Envy24Control.README )
........
On a completely different "note" the envy 24 manual (
http://alsa.cybermirror.org/manuals/icensemble/envy24.pdf )
has interesting info on the envy24 digital mixer that I've snapshotted:
Diagram: http://nielsmayer.com/npm/envy24mixer-architecture.png
Note the way it truncates in the mixer: the more inputs you "mix" at
once, the fewer bits each input source gets, and it's not clear what
kind of dither, or it's a straight truncate of 24... ultimately the
envy24 seems oriented towards producing a 16 bit, and not 24 bit
master (which makes sense given that the chip is well over a decade
old and HD audio production for "prosumer" was rare):
..........
4.5.5 Multi-Track Digital Monitoring
The Envy24 integrates a 36-bit resolution digital hardware mixer. The
width of the data path is strictly to
ensure that during processing of all the channels, under any
condition, no resolution is lost. The dynamic range
of the end user system will be limited by the range of the physical
output devices used. In order to maintain
identical gain to the input stream (i.e. 0dB), the resulting 24-bit is
not msb-aligned to the 36-bit. The overflow
bits correspond to the analog distortion due to saturation. The user
would need to reduce the overall attenuation
of the inputs to avoid clipping. Insertion of the digital mixer adds
only a single sample cycle delay with respect
to the original data. This extremely low latency all digital mixer
provides monitoring functionality and can
replace a traditional external analog input mixer. There are 20
independent audio data streams to mix and
control the volume. ...
..............
--Niels
http://nielsmayer.com
Hi :)
my PCI MIDI devices passed the alsa-midi-latency-test always with < 1.01
ms, on several Linux, with several kernels and graphic drivers. It's
audible that this can't be true. I was sceptic, when my USB MIDI passed
with around 2 ms, because recordings did show that there is much more
latency for the USB MIDI, when using Linux, just Windows is able to do
such less jitter on my machine, see the archives. I won't install
Windows again to compare the PCI MIDI. This computer can do better, but
MIDI fails for Linux. This comparison is just for testing the abilities
of the hardware.
Please test yourself what I did today and you'll be able to here it too.
It isn't just audible for gifted musicians, you'll really here that the
FluidSynth DSSI Kick and the Kick played by an external MIDI drum module
will be played one after another, but in unison. Note that I tested,
that this drum module still is 100% ok.
Please read the test and do the same as I did.
I decided to do the audio MIDI jitter test with 64 Studio 3.3 alpha. I
kept the proprietary 'nvidia' driver, even if the 'nv' driver, used by
64 Studio 3.0 beta, seems to cause x*10 µm less jitter.
First I checked the package 'rt-irq'. It's version 20090810-0ubuntu1
(karmic) and regarding to diff, I didn't over installed the current
version before. On Rui's download page http://www.rncbc.org/jack/ the
current version is 20090920.
I installed a dummy package rtirq-init_20090920_all.deb and updated both
rtirq files.
For /etc/default/rtirq I edited
line 30 from
RTIRQ_NAME_LIST="rtc snd usb i8042"
to
RTIRQ_NAME_LIST="rtc snd i8042"
line 33 from
RTIRQ_PRIO_HIGH=90
to
RTIRQ_PRIO_HIGH=98
I fixed the MIDI adaptor cable by screws to the 16:0 device and used the
audio IOs of the same card. It's the card with IRQ 20. Envy24 Control
automatically chose this card.
After shutdown and startup I did perform the ALSA MIDI latency test.
$ su -c "poff dsl-provider"
$ su -c "cpufreq-selector -g performance"
^C
$ cd /etc/init.d
$ ./rtirq status
PID CLS RTPRIO NI PRI %CPU STAT COMMAND
386 FF 95 - 135 0.0 S< irq/8-rtc0
1140 FF 90 - 130 0.0 S< irq/21-ICE1712
1137 FF 89 - 129 0.0 S< irq/20-ICE1712
379 FF 85 - 125 0.0 S< irq/1-i8042
378 FF 84 - 124 0.1 S< irq/12-i8042
102 FF 50 - 90 0.0 S< irq/9-acpi
565 FF 50 - 90 0.0 S< irq/14-ide0
570 FF 50 - 90 0.0 S< irq/16-ohci_hcd
587 FF 50 - 90 0.0 S< irq/22-ahci
597 FF 50 - 90 0.0 S< irq/19-ehci_hcd
598 FF 50 - 90 0.0 S< irq/22-ohci1394
601 FF 50 - 90 0.0 S< irq/17-ohci_hcd
603 FF 50 - 90 0.0 S< irq/18-ohci_hcd
606 FF 50 - 90 0.0 S< irq/17-ohci_hcd
609 FF 50 - 90 0.0 S< irq/18-ohci_hcd
932 FF 50 - 90 0.0 S< irq/7-parport0
1634 FF 50 - 90 0.3 S< irq/18-nvidia
1946 FF 50 - 90 0.0 S< irq/26-eth0
4 FF 49 - 89 0.0 S< sirq-high/0
5 FF 49 - 89 0.0 S< sirq-timer/0
6 FF 49 - 89 0.0 S< sirq-net-tx/0
7 FF 49 - 89 0.0 S< sirq-net-rx/0
8 FF 49 - 89 0.0 S< sirq-block/0
9 FF 49 - 89 0.0 S< sirq-tasklet/0
10 FF 49 - 89 0.0 S< sirq-sched/0
11 FF 49 - 89 0.0 S< sirq-hrtimer/0
12 FF 49 - 89 0.0 S< sirq-rcu/0
18 FF 49 - 89 0.0 S< sirq-high/1
19 FF 49 - 89 0.0 S< sirq-timer/1
20 FF 49 - 89 0.0 S< sirq-net-tx/1
21 FF 49 - 89 0.0 S< sirq-net-rx/1
22 FF 49 - 89 0.0 S< sirq-block/1
23 FF 49 - 89 0.3 S< sirq-tasklet/1
24 FF 49 - 89 0.0 S< sirq-sched/1
25 FF 49 - 89 0.0 S< sirq-hrtimer/1
26 FF 49 - 89 0.0 S< sirq-rcu/1
$ su -c "chgrp audio /dev/hpet"
$ su -c "sysctl -w dev.hpet.max-user-freq=64"
$ su -c "modprobe snd-hrtimer"
$ alsa-midi-latency-test -l
Port Client name Port name
14:0 Midi Through Midi Through Port-0
16:0 TerraTec EWX24/96 TerraTec EWX24/96 MIDI
20:0 TerraTec EWX24/96 TerraTec EWX24/96 MIDI
$ alsa-midi-latency-test -Rrw=5 -i16:0 -o16:0
> alsa-midi-latency-test 0.0.3
> set_realtime_priority(SCHED_FIFO, 99).. done.
> clock resolution: 0.000000001 s
sample; latency_ms; latency_ms_worst
0; 1.07; 1.07
9999; 1.00; 1.07
> latency distribution:
1.0 - 1.1 ms: 9994
##################################################
1.1 - 1.2 ms: 6 #
> SUCCESS
best latency was 0.99 ms
worst latency was 1.07 ms, which is great.
$ alsa-midi-latency-test -Rrw=5 -i16:0 -o16:0
> alsa-midi-latency-test 0.0.3
> set_realtime_priority(SCHED_FIFO, 99).. done.
> clock resolution: 0.000000001 s
sample; latency_ms; latency_ms_worst
0; 1.06; 1.06
timeout: there seems to be no connection between ports 16:0 and 16:0
I didn't check any connections, but run the test again. I've got no idea
what's wrong, when I get those timeouts. The adaptor cable with
opto-coupler is a brand new non self made one and the timeout can happen
for both cards, my old card S/N 00xxxxx with an Envy24 chip not by
Terratec and the new second hand card from Ebay S/N 04xxxxx with an
Envy24 chip by Terratec.
I didn't compare all the other chips, but the board's layouts don't
differ.
When doing the audio MIDI test the MIDInterface did work without missing
data.
$ alsa-midi-latency-test -Rrw=5 -i16:0 -o16:0
> alsa-midi-latency-test 0.0.3
> set_realtime_priority(SCHED_FIFO, 99).. done.
> clock resolution: 0.000000001 s
sample; latency_ms; latency_ms_worst
0; 1.06; 1.06
5727; 1.06; 1.06
9999; 1.01; 1.06
> latency distribution:
1.0 - 1.1 ms: 9992
##################################################
1.1 - 1.2 ms: 8 #
> SUCCESS
best latency was 0.99 ms
worst latency was 1.06 ms, which is great.
Compared to the test done with the old setup
http://lists.64studio.com/pipermail/64studio-users/2010-July/004537.html
nothing did change.
$ jackd -Rch -dalsa -dhw:0 -r96000 -p1024 -n2
jackdmp 1.9.5
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 10
creating alsa driver ... hw:0|hw:0|1024|2|96000|0|0|nomon|swmeter|-|
32bit
Using ALSA driver ICE1712 running on card 0 - TerraTec EWX24/96 at
0xcf00, irq 20
configuring for 96000Hz, period = 1024 frames (10.7 ms), buffer = 2
periods
ALSA: final selected sample format for capture: 32bit integer
little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer
little-endian
ALSA: use 2 periods for playback
$ qtractor
Version: 0.4.6
Build: Jun 3 2010 15:26:56
JACK Session support disabled.
A Yamaha DX7 was directly connected to hw MIDI in and an Alesis D4 was
directly connected to hw MIDI out. The analog audio IOs from the sound
card and the main outs from the Alesis D4 were connected to a Behringer
UB2442FX-Pro. So, valid home recording equipment, without any critical
stuff. Excepted to the limit for the sound quality, there shouldn't be
any issues caused by this setup.
For the MIDI audio test's LXDE session I'm running GNOME terminal tab 1
JACK2, tab 2 Qtractor. Evolution offline + this Email opened for writing
to the lists. Envy24 Control and nothing else.
For Qtractor I switched from queue timer (resolution) 'system timer
(1000 Hz)' to 'HR timer (1000000000 Hz)' and restarted Qtractor.
1.
I disconnected all audio connections for JACK and connected hw MIDI in
to hw MIDI out. Live I played forefinger left hand kick, thumb left hand
snare and forefinger right hand ride.
To get an impression for the latency I connected the DX7 MIDI out
directly to the D4 MIDI in and then I reconnected to the PCI card.
The difference is alarming :(.
Yamaha DX7 --> Alesis D4 results in a 100% musical groove.
Yamaha DX7 --> PC --> Alesis D4 results in extreme latency, it's hardly
possible to keep on grooving. This never ever is a latency of just 1 ms,
I'm sure the ALSA MIDI latency test is mistaken. Even a MIDI thru chain
by several MIDI devices won't cause such bad latency.
2.
I disconnected all ALSA MIDI connections. I disconnected the DX7 from
the hw interface.
Qtractor was connected to hw MIDI out, while hw MIDI out still was
connected to the D4.
3.
After adding a MIDI track I added a MIDI clip (from bar 2 to bar 4, 4/4,
120BPM) with those notes:
Time_____Note_____V._Duration
2.01.000 (36) C 1 64 0.00.240
2.02.000 (37) C#1 64 0.00.240
2.02.480 (36) C 1 64 0.00.240
2.03.480 (37) C#1 64 0.00.240
2.04.000 (36) C 1 64 0.00.240
2.04.480 (37) C#1 64 0.00.240
2.04.720 (36) C 1 64 0.00.240
3.01.000 (36) C 1 64 0.00.240
3.01.480 (37) C#1 64 0.00.240
3.02.480 (36) C 1 64 0.00.240
3.03.240 (36) C 1 64 0.00.240
3.03.480 (37) C#1 64 0.00.240
3.04.000 (36) C 1 64 0.00.240
3.04.480 (37) C#1 64 0.00.240
Loop play for hw MIDI by Qtractor is a disaster, hence I copied and
paste repeated it 39 times, pasted with the grid set to beat. The
'rhythm' then was from bar 2 to bar 82.
4.
After adding a second MIDI track, I copied all clips from the first to
the new track.
The second track isn't for hw MIDI, but FluidSynth DSSI.
I connected Qtractor audio out to system playback.
Before I could play with the hw MIDI track muted, Qtractor crashed.
I opened a third tab for the GNOME terminal and tried to kill Qtractor
without success.
$ su
# pidof qtractor
4173
# kill 4173
# killall qtractor
# killall -9 -w qtractor
^C
# killall -9 qtractor
I stopped JACK.
[...]
JackAudioDriver::ProcessAsync Process error
JackEngine::XRun: client = Qtractor was not run: state = 1
JackAudioDriver::ProcessAsync Process error
JackEngine::XRun: client = Qtractor was not run: state = 1
JackAudioDriver::ProcessAsync Process error
JackEngine::XRun: client = Qtractor was not run: state = 1
JackAudioDriver::ProcessAsync Process error
JackEngine::XRun: client = Qtractor was not run: state = 1
JackAudioDriver::ProcessAsync Process error
JackAudioDriver::ProcessAsync Process error
^Cjack main caught signal 2
Unknown error...
FATAL: exception not rethrown
Aborted
But ...
# killall -9 qtractor
didn't work.
FWIW the Alesis D4 was set up to
NOTE: 036 C1
Kik/43: Slammin'
PITCH: +1.00
VOL: 99
PAN: <>
OUTPUT: MAIN
MODE: MULTI
NOTE: 037 C#1
Snr/92: Big Stik
PITCH: +1.00
VOL: 85
PAN: <>
OUTPUT: MAIN
MODE: MULTI
CHANNEL: 01
As usual for 64 Studio 3.3 alpha several restarts resulted with issues.
I had to turn the computer off and on.
1.
Started GNOME terminal tab 1.
su -c "poff dsl-provider"
2.
Started Evolution in offline mode and opened this Email.
3.
GNOME terminal tab 1
$ su -c "cpufreq-selector -g performance"
Password:
^Cspinymouse@64studio:~su -c "chgrp audio /dev/hpet"
I wonder why Ctrl + C is needed after running cpufreq-selector.
For Lucid it's the same.
$ su -c "sysctl -w dev.hpet.max-user-freq=64"
$ su -c "modprobe snd-hrtimer"
$ jackd -Rch -dalsa -dhw:0 -r96000 -p1024 -n2
4.
Opened a second tab for GNOME terminal.
$ qtractor /mnt/music/all-in-one_supplier/PCI_MIDI_test.qtr
HR timer still is selected.
The hw MIDI track is muted.
The FluidSynth DSSI MIDI track is ready to play.
FluidSynth is using 808Set.sf2.
Qtractor audio out was connected to system playback and system capture
was auto-connected to Qtractor audio in. I now disabled auto connect,
but kept this audio connections, resp. I had to manually restore them,
perhaps disabling auto connect, did disconnect them.
I had to disconnect and manually restore Qtractor MIDI out, because it
didn't connect to the 16:0 EWX 24/96 as stored, but to the 20:0 EWX
24/96.
5.
I launched Envy24 Control.
6.
I pushed play for Qtractor transport.
I stopped it.
Set up gain for FluidSynth from the default -14 dB to 0 dB.
Played again.
Unmuted the hw MIDI track.
The notes played by the soundfont and by the D4 are fluctuating between
completely being out of sync and between being played unison.
I stopped playing.
RESULT
THE PCI MIDI INTERFACE WITH AN ALSA-MIDI-TEST-LATENCY RESULT OF < 1.1 ms
IS COMPLETELY USELESS TO MAKE MUSIC, BUT 'GREAT'.
AND IT'S AUDIBLE THAT THERE IS MUCH MORE JITTER BUT 1.1 ms.
Any hints how to solve this are welcome.
What information is needed?
Cheers!
Ralf
Shit, I tried to do some research, but
lad.linuxaudio.org and linuxav.org/mailarchive seem to be down :( and it
seems that my last mail didn't come through the list :(.
Has anybody else this trouble?
If not please send me an email.
Shit!
Ralf