The Vector Linux packager for Audacity came up with a fix for this, which is :
1) start Audacity (with playback=record=alsa default)
2) killall jackd
3) now can record
This works for me
It seems this is all to do with a longstanding Jack-related Audacity bug.
I have 1.3.4 running under Vector Linux 5.9 Gold (Slackware) with an Audigy 2 Value soundcard. I want to record from the microphone. When I try to setup the input device, I get a drop-down list with 7 choices, including "Alsa Default", but the only one that actually works is "Jack Audio Connection K...