VST Program Change = minor audio glitches pops & poofs

[Synner]

Help!

Ok - I've been at this for quite some time - building my "perfect" performance system...

I am hosting 8 Virtual VST Synths across two computers and two copies of Ableton Live.
My goal is to be able to have access to 20 pre-programmed sounds per virtual synth available during live Live performances...

I must first say that everything is working beautifully - including BPM sync across all the hardware and VSTs.

MY PROBLEM:

When sending midi patch change commands to some VST synths - I get very minor audio glitches or small pops and poofs in the main output. Minor yes - but they are there!

I have it set up so that only one VST track receives the midi program change at any one time - the other tracks are not activated.

It happens with FM7, impOSCAR and the miniMOOG VSt.

It happes on both PC's.

It doesn't happen on Absynth. Albino, Blue, Wave or Vanguard.
(could these be coded more closly to the VST specs?)

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I have played with various buffer settings to no avail (just get the same result and more latency).

I've tried giving Live a higher task priority. Makes it worse...

The system spec on both machines is top end with loads of memory, powerful CPU's and I'm using Delta 1010's with ASIO drivers for the hardware in/out...

My CPU usages in Live are 18% and 12% respectively...

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I added the second CPU to share the workload and it has done wonders.

Now if I could just solve this last very irritating problem... I can start making some recordings!

Any suggestions?

Synner

[aidoDel]

Hi I cant really help with your problem but you may be able to help me with mine. Is it possible to write midi in the midi editor to control program changes within a VST (eg FM7). I want to Ableton to change FM7s progam presets continually throughout my songs.
It seems you can only control pitch, control change, pan, volume and send.
Do you know if its possible ?

[Synner]

I am assuming you have some form of controller that will allow you to send a program change message. Simply record the program change as a midi clip and trigger it when needed in session view. Or if you wish to do this automatically throughout a song - record the program change on a track on the timeline where you want the change to happen.

Synner

[davec1]

I get a very major glitch when switching absynth 4 presets via program change midi messages. for some strange reason, that doesn't happen when selecting patches from the patch select window in the vst window....

[hardshell]

Or if you wish to do this automatically throughout a song - record the program change on a track on the timeline where you want the change to happen.

As far as I can tell, it is not possible to actually record multiple program changes within a single MIDI clip. Live does not allow program changes to be controlled as seperate values within a MIDI clip, instead you can only set one program change per MIDI clip, regardless of its length.

The way I work around this is to create psuedo-clips for the MIDI device which contain nothing but the desired program change. For example, if I start the track with program change value 1 and at bar 16 want to change to program change value 2, I create a tiny MIDI clip at the start of the track with program change value 1 assigned to it, and another one at bar 16 which has program change value 2 assigned to it.

If anybody has a better way of doing this then please post your suggestions as it's been doing my head in working this way!

[Pasha]

I do as hardshell suggests.
I have noticed that even with External MIDI modules, if the selected sound is too heavy the program change cannot be sent at the same poisition the 1st note is supposed to play.
With VSTs (including Operator's Hot Swap mode) this happens because VSTs use the same resources as Live to generate sounds. If you have a long reverbered tail or a sustain pedal tail, you cannot change the preset while the CPU is still generating the tail of the sound.
So a prg change (Live has only clips to do this, it does not manage program change at the track level and you cannot automate it - Abes you listening?)
must be given in advance to avoid those problems.

- Best
- Pasha

[hardshell]

I guess there must be a reason why the Abletons have set up program changes this way? Live is such a genius piece of software that it seems very odd program change data cannot be amended across the timeline, like you can in Logic for example.