[LAU] Sustain pedal issue with undesired repeated notes (m-audio keystation 88es + qjackctl + qsynth)

[Nicolas BERCHER]

On 08.06.2010 11:12, david wrote:
> Nicolas BERCHER wrote:
>> On 06.06.2010 23:44, Ken Restivo wrote:
>>> On Sun, Jun 06, 2010 at 10:15:03AM -0400, Dave Phillips wrote:
>>>> Nicolas BERCHER wrote:
>>>>> I have a problem I can't face alone on the digital piano I made on
>>>>> Debian Lenny with qsynth (v0.2.5-2.2), qjackctl (v0.3.2-1) and an
>>>>> m-audio keystation 88es keyboard.
>>>>>
>>>>> When I play the piano, some notes will repeat themselves after a few
>>>>> seconds only if I keep the sustain pedal pressed, just like a delay
>>>>> effect would do.
>>>>> I reported that only 4 notes are concerned for the moment, they have
>>>>> different repeat delays:
>>>>>   G  : ~7.5 sec (G4)
>>>>>   G# : ~7 sec (G#4)
>>>>>   A  : ~6.5 sec (A4)
>>>>>   A# : ~6 sec   (A#4)
>>>>> Note that the notes above, relatively to the middle C of a piano
>>>>> keyboard called C3, goes from G4 to A#4.
>>>>>
>>>>> Could this be due to an hardware issue in the m-audio keyboard?
>>>>>
>>>>> Thanks a lot for any idea on how to track down and correct this (if
>>>>> possible).
>>>>
>>>> Try putting a MIDI monitor program between the keyboard's MIDI output
>>>> and QSynth's input port in QJackCtl. Look for the repeats there.
>>>>
>>>> If you have KDE: http://kmidimon.sourceforge.net/
>>>>
>>>> For Gnome/GTK: http://home.gna.org/gmidimonitor/
>>>>
>>> For none of the above (my preference): aseqdump :-)
>>>
>>> -ken
>>>
>> Thank you for answers.
>> Yes, I also prefer command line tools! ;-)
>> So, I checked what's going on:
>> $ aseqdump --list
>>  Port    Client name                      Port name
>>   0:0    System                           Timer
>>   0:1    System                           Announce
>>  14:0    Midi Through                     Midi Through Port-0
>>  20:0    SB Live! Value [CT4870]          EMU10K1 MPU-401 (UART)
>>  24:0    USB Keystation 88es              USB Keystation 88es MIDI 1
>> $ aseqdump -p 24:0
>> Waiting for data. Press Ctrl+C to end.
>> Source_ Event_________________ Ch _Data__
>>  24:0   Control change          0  64 127
>>  24:0   Note on                 0  82  82
>>  24:0   Note on                 0  82   0
>>  24:0   Control change          0  64   0
>>
>> The above sequence dumped by aseqdump shows only one note event 
>> (lines 2+3: press+release) but I heard a delayed note as mentioned in 
>> my first mail.
>> The keyboard seems to do things right, so I think it comes from qsynth.
>> Isn't that strange? I mean many people around there use qsynth, am I 
>> the only one to have this kind of problem?
>
> Hmm, have never had QSynth repeat a note unless I actually repeated a 
> note. Interesting. I don't know the innards of MIDI events, so don't 
> know what the various numbers above mean.
>
> WAGging around: Is your USB MIDI connection sharing a USB bus with 
> other USB devices? Maybe some other USB device is doing something 
> weird with the bus and something isn't getting handled right?
>
# lsusb
Bus 002 Device 005: ID 0763:0192 Midiman M-Audio Keystation 88es
Bus 002 Device 002: ID 413c:2003 Dell Computer Corp. Keyboard
Bus 002 Device 003: ID 0461:4d15 Primax Electronics, Ltd Dell Optical Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 004: ID 0bda:0103 Realtek Semiconductor Corp. USB 2.0 
Card Reader
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

I guess you're right: I have 2 USB buses (one onboard (2nd) and one in 
front (1st), inside a memory cards reader) and the midi keyboard shares 
the 2nd bus with mouse and azerty keyboard...
I noticed there's no way to plug an usb device on the 1st bus: it only 
cares about memory cards.
So I unplugged both mouse & azerty keyboard but it doesn't change anything.

Do you think this problem could come from an hardware failure into my SB 
Live sound card?

Nicolas.