GPG Services expert settings
Important: Please only proceed, if you really know what you are doing. The settings that can be activated are hidden for a reason. We don't want you to be stuck with a non-working version or unusable keys or insecure settings!
To enable ASCII armor as default output, open Terminal.app, paste the following line and press enter
defaults write ~/Library/Preferences/org.gpgtools.gpgservices UseASCIIOutput -bool YES
To deactivate ASCII armor as default
defaults write ~/Library/Preferences/org.gpgtools.gpgservices UseASCIIOutput -bool NO