Linux Jack: First Pattern Note Does Not Play When Looping Pattern


I am using the renoise demo on Ubuntu studio 10.04. Most things seem to be working well, but when I enter a 2 bar drum loop starting on row 00 and again on 32, 00 does not play after the first pattern loop. The note on 32 triggers on each loop, but 00 only once when starting the first loop.

If I press enter on the 00 row the loop plays, but using psace bar or the play button I get this problem. Is there a setting I’m missing?



Enter key, on the numpad, is the default shortcut for “Block Loop”, you may be inadvertently activating it.

Thanks for the reply. Its definitely not due to ‘block loop’. Any other ideas?


What are you triggering, an internal instrument or an external MIDI device?
We have had earlier reports about the “first note” not triggering in serveral different occasions.
Is Jack involved? or are you using Pulse audio, are you triggering another host through Jack? etc.

I am triggering an internal instrument, which at the moment is a single sample drum loop.

Prompted by your reply, I tried both Alsa and Jack output. The triggering problem only happens when Im using jack, but when I use alsa direct I get audio distortion. The distortion is improved slightly by increasing the buffer size, but I can’t get rid of it. I believe pulseaudio is killed when jack starts, but it could be interfering when I use alsa.

Is there a workaround which will allow me to use Jack? I should add I was having midi problems with the alsa packaged with 10.4, so upgraded to the latest 1.0.23. Im not having problems with any other application though.



Could you please check if the Jack transport is the problem here? See option “Enable Transport support (master & slave)” in Renoises audio preferences pane.

if you don’t need to sync the transport of multiple running Jack clients, you can safely disable this option.

A bit of a hasty response! I have just disabled ‘enable transport support (master & slave)’ and the first note is now played using jack. Up until now I have not used the jack transport controls, so I can live without this. However, should this not be working? If I have a more complicated setup in the future, these central transport controls may be useful.

Thanks for your quick replies.


Yes, of course this should work, but is quite complicated. Jack transport does not pass along loop positions with its transport info, which is the main problem. We also have some other problems with other details in the Jack transport specs, that make it really hard, if not impossible, to sync Renoise perfectly with other clients. We’ll try to take care of this in future…

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