Ok,
Thank you for all your help!

Ok, an osc~ 440 to dac~ works! As does replacing the notein etc with metro. Thank you very much for your help. What exactly was the issue causing the error? I actually wasn't using any midi at all and thought just clicking the bang would generate the audio

Yep, confusing to me too. Will try right now.

Should 'callbacks' be on or off?

Hmm... Doesn't seem to be making a difference.

i'm now getting the audio i/o error again too.

Also,
here are my audio settings.

Sure,
I'm currently building a drum sequencer, this is my hi-hat patch.PD hi-hat with pan.pd

@rjp9 Thanks for quick reply. Sorry away from the Mac at the moment so can't post a screen cap.
They seem to be how I'd expect them. Both the input and output have one option being the built in mic and speakers. Both boxes are checked too.

Hi,

I'm new to PD, using it as part of my uni course.
It's been running perfectly well for a while but I just got a new Mac, installed PD exactly as I did before, I now get no audio.
The test audio feature works fine and I can hear it clearly, however even a simple osc object into a dac produces no audio output.
The very first time I launched PD on the new Mac and turned on DSP I got an audio I/o error message, so I checked my settings, everything is set to the only available ins and outs (the built in ones) which should be correct.
I've never had the error pop up again since, but still get no audio.

Any help would be appreciated!