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  • Multiple VE2 instances, IAC busses cutting out

    Hi there

    I recently setup logic with VSL on my new Mac Pro, using the IAC busses to route audio into a number of separate instances of Vienna Ensemble (duplicate & rename app), as recommended by VSL.

    Everything works fine most of the time, but every few hours one of the VEs stops receiving MIDI. If I go into the preferences of the one that's stopped and just click OK to exit, it starts receiving MIDI again, but then connection to the others is broken instead, ie I can only get one instance to work at any one time.

    I tried working with 3 instances initially but this was totally unreliable. I now work with 2, and another hosted from the Logic AU, which is better but still a couple of times a day I get this problem and have to reboot and reload everything (which takes 20 mins each time), often it seems after short breaks away from the computer.

    I have downloaded a little program called Midifork which outputs note sequences on the IAC busses, and the behaviour of the VEs is identical to when I'm playing the notes from Logic. So I'm not convinced it's a problem with Logic, although I would be happy to hear of other people's experiences with the Environment (I have my IAC objects cabled to the MIDI Monitor to stop MIDI loop).

    I know the IAC busses have a reputation for being flaky, but surely there must be lots of VSL/Logic users who have this working successfully? Any thoughts on what is going wrong?

    Many thanks in advance for any help.


    Logic 8.0.2 / OS10.5.7 / Mac Pro 8 x 2.16GHz 12MB

  • Hey Harry,

    I pretty much have the same setup that you have but my IAC busses work.  I will describe my setup to you so you can see if there are differences or things that you might want to add to your setup:

    In the Audio/Midi preferences on mac os, I have the IAC bus active, which has 8 ports activated in itself.

    In the VE instances, all 8 IAC bus ports are chosen in the preferences.  I have noticed that configuring one copy of a VE instance will duplicate its preferences in another VE instance.

    In the environment window of logic, in click & ports, I have the sum cable removed and instead I directly routed my midi controller to "Input Notes", which then goes through a monitor and then to the sequencer input, though I'm sure that my midi controller could go directly to my sequencer input.      **The reason I have disabled the sum cable is because I have encountered midi loop issues, and so far removing that sum cable has been great.**

    Now, still in the environment window, in MIDI Instr.  I have 8 multi-instruments, each assigned to each IAC Bus.  Make sure each of their channels isn't crossed out by click on each of them.

    That's pretty much it on the midi side.  No midi loops whatsoever, which are I think due to the disabled Sum cable.

    On the audio side, I use JackPilot (free software) to route my VEs to Logic.  A lot of people talk about using Soundflower, but after trying both extensively, JackPilot is much more efficient, versatile, and useful.

    In JackPilot you can pretty much reroute audio from any software to any other software.  Of course those programs have to use JackPilot as a sound device.  You can assign an almost unlimited amount of inputs and outputs to applications.  So I basically route each output from the VE's to the inputs in Logic.  Performance is flawless and you can save your routing environment in JackPilot.

    In Logic you can then create audio tracks and assign those inputs to them, or use Aux tracks, whichever you prefer.

    This is basically my setup for Logic and standalone instances of VE.  I run 3 instances but have run more in the past without a problem.

    Oh, one thing about VE's midi preferences.  Even though I have read that VE can only use a max of 8 midi ports, you can technically select a lot more in the preferences.  The problem is, if more than 8 ports are chosen, the ports won't appear in order when you try to select them in your VI's.  But that's only a minor thing.

    I'm guessing that your problem lies in still having the Sum cable attached to the sequencer input in Logic.

    Hope this helps,


  • Hi Sebastien

    Sorry only just saw your reply. Many thanks for your pointers, I will check all this out this week.

    Best wishes


  • It may also be caused by energy saving prefs-If the machine or drives go asleep after a certain time it may cause problems like this..

  • Hm maybe, but for some reason I doubt it, my external drive will go to sleep after a while, but it never causes the IAC buses to cut out.  Have you been able to connect your midi keyboard to logic?

    In logic's environment in "clicks & ports", you should have an object called Physical input.  This is where the SUM cable should have come from. In this object you should see all your midi ports that are available.  Your IAC Buses should be there as well as your MIDI interface's ports.  Just find where on your midi interface your keyboard is connected to and route that to the sequencer input.

    I suggest having a "monitor" object and/or a "keyboard" object (they should already be there by default; they are renamed "Input View" and "Input Notes" respectively) between the physical input and the sequencer input, so that you can monitor the midi activity.  If you connected the right port, you should see activity in the "input view" and "input notes" object.

  • Hi all

    Many thanks for your suggestions on this. Having got some time to do some proper testing on my setup, I have found out the culprits: 

    1) there seems to be some conflict between the IAC busses and the MIDI connections into Plogue Bidule (which I am using to host my Kontakt instances). The solution was to disable all Budule's own MIDI connections and instead use additional IAC busses to route note information into it.

    2) the IAC busses stop working properly after the computer wakes from sleep (thanks rharman).

    So now I have 3 VSL app instances running successfully, and as long as I disable sleep everything seems to be working fine!

    Thanks again