playback dropping out

Has anyone had issues with playback dropping out randomly? I am getting like short half-second glitches during active playback that don’t occur at the same place each time I playback. If I export to wave or MP3 they are not there, just during normal playback. Most of the VSTs I use don’t cause this much but I seem to be having a lot of trouble with UVI Workstation. Is it because it is a VST 2 or is there something else I can check?

Difficult to say why you are getting drop outs. There are so many parameters that influence the performance. Starting with the spec of your machine, going over the audio interface and the used driver, the complexity of the project, the number of instruments used until the individual plug-in settings. VST2 doesn’t mean necessarily bad performance, it depends on how good the programmers did their job.
Furthermore, have a look at UVI’s own settings. E.g. HALion Sonic SE has an options page where you can control how many cores it will use and the maximum number of voices. Playing with these parameters can already improve the drop out situation.

Here’s some more information: My machine is 6 core I7 with 128GB and multiple PCI SSD drives so I don’t think horsepower is the issue. I only have 2 tracks and about 20 measures. I tried cranking up everything on UVI that I could (which is just basically the cache size) and I also tried both the ASIO driver that comes with Dorico (runs on soundcard) and I also ran it through a Presonus Firestudio Project with its own ASIO driver. The problem persisted through these experiments. By the way, I do not have this problem with UVI and my DAW so it seems related to the Dorico playback engine. Any other things I can try?

Hm, horsepower really is not an issue with your machine. At what buffer size are you running the driver? Though, it shouldn’t matter with that small project size you have.
Do you use wireless network on your machine? We know that bad drivers can compromise the ASIO performance. On my Thinkpad here I have the same issue, that the WLAN can cause drop outs, but usually only on really heavy projects.

I’ve just downloaded the free UVI Workstation and played with the few demo sounds that are available and no problem at all on my machine. Could you please send your project to u dot stoermer at steinberg dot de? Let’s see how that behaves here.

I tried a few more experiments. I am using the Bohemian Violin from Virharmonic with UVI. Its a huge library (>15GB) so I thought that may be the main problem. To confirm, I tried some of the small UVI demo sounds like you did and they indeed work fine. However, its not just the size of the libraries by itself because I have a project with over 90GB of east west instruments loaded and running and it doesn’t have a problem. Its strange because UVI/Bohemian violin doesn’t have an issue with my DAW(s), only on Dorico.

Then, just out of curiosity, I tried the same UVI project on my old junky 5 year laptop with only 8GB of memory and the library streaming from an external hard drive. I thought it would choke but not a single drop out! So, looks likes somethings funny with my hotrod desktop, I’m clueless what it could be. In any case, I doubt you can really help me so please go back to making Dorico even more awesome (I’m partial to playback improvements)

Really interesting what you are writing, though - honestly - I have no clue what might be the cause for that. I got the free Violin from Virharmonic and sure, it is pretty reduced and not comparable to the Bohemian, but that also does work fine for me. I loaded a Schubert string quartet and replaced Violin 1 and 2 by Virharmonic and the playback runs as expected and without dropouts.
Would be interesting to see how UVI/Bohemian behaves in Cubase, because Cubase and Dorico share basically the same audio engine. You could get a free trial of Cubase Elements from here:

What sample are you using for your audio? What is the OS version?

Try a lower sample rate (say 48 kHz) to see if there’s a difference.

Double check for DPC latency on Windows:


Hello pxm. I’ve occasionally had random drop-outs or missing bits playback while working in write mode. Found that simply switching to another mode then immediately back to write mode clears the glitch or whatever causes the problem.

Thanks for the feedback. I tried the 48 khz version of the violin and it improved significantly on the desktop machine, but not completely eliminated The other weird thing is that the playback lags the green bar (on all the screens) by a couple of measures and sometimes the bar gets stuck. My old laptop handles all this with no problem. I’d use that laptop except it doesn’t have enough memory to load all the VST instruments I’m using. I’m still suspecting some driver issue.

That the green bar lags behind is really unusual and shall not be. That could happen in the case that Dorico and the Audio Engine disagree over the currently set sample rate.
Please try following:
Go to Edit > Device Setup and change the sample rate to a different value. Close the dialog,open it again and set the sample rate back to the initial value. Now start the playback again, still the same lag?

I would tend to agree. What you can do is use LatencyMon to test your newer system and see which driver/process might be hanging you up. (Ethernet & display cards are often the culprit.) Updating the suspect driver will often do the trick.

Alternatively, you might have a flaky ASIO driver. You can see if ASIO4ALL makes a difference.