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Qtractor Question re .qtc files for mapping AKAI APC Key 25


Firstly, thank you for making QTractor available. It is a great looking product that I am keen to experience fully once I get my new MIDI controller correctly configured.

I am a newbee to QTractor and am thoroughly enjoying the experience so far.

I am using the AVL-MXE-2020.12.03-xfce4-amd64.iso distribution (now patched to the latest), on an Acer Aspire E1-571 laptop with Intel i3 2.5GHz and 4gb ram. Probably under powered, but it is all I have.

In the document entitled "qtractor-manual-and-howtos.pdf" downloaded from, files with the extension .qtc is mentioned once on page 55 under the "View / Controllers menu" section.

I am trying to connect an Akai APC Key 25 to QTractor to give me some the functionality that Ableton has built into their software according to the "Akai APC Key 25 User guide" available at

Unfortunately, being a newbie to the MIDI world, I cannot even find ANY of the kinds of commands that a MIDI controller may issue to a DAW in general.

I have used the Linux command 'aseqdump -p 20 > textfile' to map all the keys and controllers, but the amazing thing is that all but three of the button outputs, produce what I would guess, are note values "N64, N71" etc. and play as such on most of the soft synths I have installed from that distros repositories. I have also saved the output of 'kmidimonitor' and confirmed that both outputs provide the same data. Only the SUSTAIN button seems to output a control value "C64" as an output, along with the 8 rotary controllers that also seem to give a control output "C48 - C55".

The OCT DOWN and OCT UP both produce N91 output, but the OCT UP enables N91 and OCT DOWN disables N91. The controller button and key MIDI output numbers and assignment (note or controller) are also confirmed by the Linux command 'midisnoop'. Output of the kmidimontor text files has been attached.

I used the 'textfile created by the 'aseqdump -p 20 > textfile' to remove all commands from all controllers, saved the result as a .qtc and imported the newly created .qtc file into Qtractor using the View -> Controllers -> Import command.

The strange thing is that even after having imported the .qtc file with all the controller commands blanked, I still find commands ascribed to the various controllers, which should, according to the way I read it, have been over-written by the imported .qtc file(??). Nor are any of them relevant in the position in which I find these commands. Where are these commands coming from in the "Type" "Channel" "Parameter" listing and are they able to be changed / over-written by the .qtc file? Some of these commands would be useful if I could assign them to different controllers.

These 'unwanted' commands appear if the MIDI Controller is attached or not, so I must assume that they are coded into QTractor or are being overwritten by General MIDI.

While I have been a Linux user for over 15 years, even the simplest bash script causes me much headache.

While I have spent a few years coding in Visual Basic for Applications (VBA - Excel and Access) I am NOT a Linux programmer and know nothing of coding Linux applications. As a result, I will NOT attempt to tinker with or alter any coding without VERY explicit instructions and guidance, which I quite sure you are not in any position to provide.

I was hoping to find a config file, but that has eluded me so far, using kfind searching for text "Portamento", which is one of the commands that I would like to move to a different location in the 'map'. But when I did find ~/.config/, this contained nothing of the MIDI mapping.

I have attached my modified .qtc file named AkaiAPCKey25_QTR-Mod2_qtc.txt, as well as the kmidimonitor output named APCKey25_KmidimonOut.txt

NB param="98" = Highest Number on any controller in the APC Key25.

I would really appreciate some help with remapping the Key 25's controllers, so that this really great looking little device becomes as useful as it would appear to be under Ableton, or at very least somewhere close to that level.

I would be happy to make to resultant .qtc(?) file available to you, once I have produced, tested and commented something that may be useful in this regard.

I have searched the web for weeks trying to find any document relating to HOW to write or input the information/commands that I want into this area of QTractor, with little success so far. I have found four, very minimal examples of .qtc files on the web with very little information as to the 'how's' and 'meaning' of these commands that are issued in the examples. I have tried to glean as much information from the excellent document "Qtractor control file explained.qtc" by Winko Erades van den Berg, and his attendant "nanoKONTROL2.qtc", but unfortunately with the nanoKONTROL2 being such a minimalistic controller, when compared to the Key 25, only very few MIDI commands could be found.

Do you have a list of the commands that are expected by QTractor in the control and the routing of that control from a MIDI controller into QTractor, as this would be a great help? If there is also a 'general purpose" list of the sorts of commands that plug-ins (mainly synthesizers) might expect, please would you provide me with a web-link to the relevant URL.

Please, are you able to help in this process?

Thanking you in advance.

rncbc's picture

hi, thanks for trying qtractor

first of all, let me say that the View > Controllers... facility, being the one that let's you edit a .qtc file, is a generic MIDI controller map for track strips controls : Gain or Volume, Panning, Monitor Mute, Solo and Record. sorry to tell, there's nothing more than that that this facility can offer; it is best and probably only suited to map MIDI controllers that present you the traditional mixer console interface: slider faders and buttons on a strip by strip basis; you may reckon Winko's KORG nanoKONTROL 2 certainly have that kind of layout :)

given that your AKAI APC Key 25 is more of a piano keyboard with a grid of clip-launcher buttons, I may have to say that it is not the best control surface for the purpose at hand; lest to say that qtractor is a traditional timeline sequencer and does not have a clip-launcher interface like Ableton Live.

so maybe I'll suggest you to look into other ways to map your MIDI controller to fit and purpose:
1. Help > Shortcuts > MIDI Controller :- this let's you map or assign a MIDI controller to any of the main menu commands (stored as application/global settings);
2. "MIDI Controller..." right-click /context-menu to most of the sliders or button controls in the qtractor GUI (stored as session/project settings).



Thank you very much for your very prompt reply to my question, which, I guess, only served to highlight my newness to this world of MIDI and softsynths.

I will only be able to try these methods later today as work demands my more immediate attention.

I will make comment / ask more questions after that.

Thanks again


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