I haven’t used Ardour in a while, so booted up my Ubuntu Studio. Seeing that a bunch of updates were pending, I went ahead and did the update. Machine is now sitting on Ubuntu 16.04.3 LTS, 4.4.0-104-lowlatency kernel.
Starting up Jack and Ardour, I loaded an old project. Playback on it is very noisy with clicks and glitches. Seeing that an update to Ardour was available (5.12, I was on 5.6,) I downloaded and installed it. Fired up again - same problem. Tried a straight midi recording - same problem.
So, I’m not sure if this is an Ardour problem, an Ubuntu problem or a bit of both. I’d appreciate any help.