Cutting the network had no effect, yes I'm running at 44.1/24, internal soundcard is deselected. When I export MIDI files as *.wav or *.mp3, the glitches are still there, but of course, now they occur in exactly the same place each time. Fritz

Were the glitches recorded on the track? Look at the waveform to determine that. If so, there's no way to remove them. Make sure your input levels don't go over 0dB. What is your ASIO buffer size? Should start with 256 samples or 128. The lower the better, but if you go too low, you'll get noise.

Are you using any other plugins aside from TTS1?   A demo perhaps?    They have a tendency to insert white noise at somewhat regular intervals.
 

 I am talking of MIDI tracks - there are no wave detailed profiles. The glitches become located and permanent when I export MIDI to Audio.

 No, I am using a clean fully licensed Studio edition and the glitches occur both in the case of a single TTS1 synth present as well as one TTS1 and one other (e.g. Cakewalk Sound Center).

When I export MIDI files as *.wav or *.mp3, the glitches are still there, but of course, now they occur in exactly the same place each time.

OK so that means that the problem is almost certainly in the digital realm. If it were an electrical problem with connection between your interface and speakers for example, it would not occur on an export.


btw you are not exporting MIDI files. MIDI files are data that are used to control the synth. What you are exporting are audio files.


You may be able to learn quite a bit by looking at those audio files inside Sonar. If you zoom in on the wave form, you can look at individual samples. Digital clipping will show as a flattening of the peak when the abnormal sound occurs. Dropouts will often show as a break in the continuity of the wave form.

I have re-imported a *.wav file into Sonar to look at the waveform. Even at maximum magnification, I could not find any visible irregularity. What I find very hard to believe is that a fairly powerful system and a standard SONAR configuration are having problems reproducing even simple MIDI-files (2 instruments only). If it were a "capacity"-problem of any sort, it should get worse with more complex MIDI-files - which it doesn't. I have now tried the simplest possible setup: One track, one synth and an instrument with a continuous tone. I press a key on the keyboard controller and the glitches randomly occur as before, they appear to be a combination between a very short dropout and a short scratchy/clicking noise. Fritz

I have heard others complain about the m-audio cards recently. Check to see if you have the most current drivers. Also check the m-audio control panel (I've forgotten its name). Are you using any spdif connections? This sounds like the card is going out of sync briefly. Also check the playback and recording masters that sonar is using. Good luck.

I am talking of MIDI tracks - there are no wave detailed profiles. The glitches become located and permanent when I export MIDI to Audio

Why don't you select the MIDI track and the corresponding softsynth track and do a Bounce to Tracks and see if the glitches show up in the resulting audio track. Maybe that may give you a clue to the issue. 

What do you have the # of samples set to in the ASIO control panel for the AP192? That's an important setting.


I agree you shouldn't be having an issue, but since you are the only one having this problem, its not a bug. It has to do with your setup. We just have to figure it out and correct it. 

Are you overdriving the output of the synth?