Well, I'm back from vacation and I want to tell everyone about a new version of Cocoa Radio. This version seems to be running really well. I've set the sample rate to 1024000 samples per second for the moment (though this value can be changed in the code), and at this rate everything seems really stable. Please give it a try and create issues if you find any problems. I should say that I'm a little tired of working on it, so unless there are major issues I'll be working on other projects for a while. I encourage others to take a look at the code if they're interested in SDR. It's not as scary as it looks!
Also, the sliders are a little buggy (especially the bandwidth ones). Move them a little bit once the app starts up and they'll work correctly.
Finally, I don't have any support for AM (amplitude modulation) yet. It's an easy modulation type, and I may add it soon.