Flat Wave Profile when recording

A 2020 iMac running Big Sur 11.2.1 and Audacity 2.4.2

It was working fine but now isn’t. iMac system prefs Sound does get input so it isn’t a physical connection problem. Sound prefs are set to USB AUDIO CODEC for Input and Output (which used to work). Tried changing Output to iMac Speakers (or headphones) and that didn’t help. Audacity settings don’t have many choices. Audio Host is Core Audio (the only choice). Recording Device is USB AUDIO CODEC (only other choice is iMac Microphone). Playback Device is either USB AUDIO CODEC (which used to work) or iMac Speakers (which doesn’t work either). Software Playthrough is On. Click to Start Monitoring is clicked. But regardless of all that, when I start Record there is nothing… just a flat line. There may have been an OS update since I last successfully used Audacity.

There may have been an OS update

I make the Mac notify me of updates and I let them happen when I’m ready. There’s nothing quite so entertaining as trying to do production and it’s a different Mac at lunch than it was at breakfast.

Excellent detailed description of the computer system. What’s the microphone or microphone and preamp? What are you recording?


Not sure about the microphone preamp question… My only recording experience is from vinyl using an audio-technical AT-LP120-USB turntable. But I mostly have used Audacity to listen to vinyl.

I have tried a complete shutdown of the iMac and that changed nothing. Wondering if I should uninstall and reinstall Audacity…

After I uninstalled Audacity and reinstalled it the problem was solved. While the settings that used to work still don’t, at least changing to other available settings does work now after the new install.

I’m surprised that reinstalling Audacity helped at all - reinstalling does not reset the Audacity configuration settings.

In the iMac Sound Input preferences, when you select the turntable and play a record does the input level meter bounce?

In System Preferences > Security and Privacy > Privacy, does Audacity have permission to use the Microphone?

– Bill

Can you get input from the USB turntable now?
– Bill