I can't change the Symphony 64 card source port setting in System Preferences

Symptom: Port Source Setting for Symphony 64 cannot be successfully changed from System Preferences/Sound.

Solution: There is a known issue with changing the Symphony64 card Source setting from 1 port to 2 ports or vice versa can cause "System Preferences/Sound" to hang or "beach ball" We recommend using Audio MIDI Setup (found in Applications Utilities Audio MIDI Setup) to change the Symphony64 card Source for the ports. Always remember to quit all applications and restart the computer after changing the number of ports.