When I tried it yesterday in Discover and with the .deb files, I only got a message about dependencies that couldn't be resolved, but there were no further details.
After trying your method with the PPAs on my main PC today, the terminal only says that these packages aren't being updated.
As I said, installing Qtractor with the .deb file two days ago wasn't a problem, but I think it was a different version then.
When I tried it yesterday in Discover and with the .deb files, I only got a message about dependencies that couldn't be resolved, but there were no further details.
After trying your method with the PPAs on my main PC today, the terminal only says that these packages aren't being updated.
As I said, installing Qtractor with the .deb file two days ago wasn't a problem, but I think it was a different version then.
The terminal shows the following:
Not updating:
qjackctl qpwgraph qsampler qsynth qtractor
Summary:
Update: 0, Install: 0, Remove: 0, Not updating: 5