Dorico Pro playback intermittent with CoreAudio OSX 10.14.6


I have a small four part score using one Kontakt 6 VST that contains the four instruments.
They are Strezov’s Freya & Wotan with just one microphone.
The samples reside on a disk that reads at 140 MB/s.
An ideas? (diagnostics area attached)

Thank you,

AlexDorico (630.3 KB)

Hm, difficult to say. In the logs I see frequently “overloadDetected” messages from the driver, but I also saw that you were trying at different buffer sizes, and even with large buffers these messages come through.
Are you using other audio apps in parallel? But even then, with a buffer size of 1024, that should be sufficiently large to run stable.
I also sometimes see blocksizeChanged messages. Unfortunately we don’t log the new size, but it suggests that some other app or component is doing this change. Do you have any idea what that could be?

Hi Ulf,
I forgot to mention that this problem happens consistently and seems independent of what VSTs are used.
The run reflected in the log was taken under the following conditions:

  • Dorico was the only running application
  • wifi was off
  • Bluetooth off
  • power saving settings - all off
  • fresh after SMC reset
  • no background tasks burning CPU, as reported by Activity Monitor

LPX has no problem with the very same score; I try this by exporting Dorico xml and importing into LPX.

Thank you,


PS Indeed, I tried all coreaudio buffer sizes.

Update, it turned out that a system task was sucking up most of the CPU cycles and by that not leaving enough power for user tasks like Dorico’s audio engine. “Calming” that system task did fix it.