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

[Nicolas BERCHER]

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?

Once again, I appreciate any advice!
Thanks,
Nicolas.