Problem: At roughly six hours and forty six minutes into a long recording, a clicking, choppy sound appears during playback of the recording and continues to the end of the recording. It occurs at the same place each time a new recording is made (at 6:45:47), and occurs likewise during subsequent playbacks as well as stops and restarts of the program.
Things done to try to eliminate the problem, but to no avail:
• Successfully applied all pending Windows and driver updates.
• Installed latest drivers for the M-Audio interface.
• Changed internal sample size from 32 bit float to 16 bit.
• Disabled all shields in my Avast virus protection software.
• Tried the long recording twice after rebooting the computer.
• Dell XPS 8300, with 8 GB DDR3 RAM, Core I7 processor running at 3.4 Ghz, 1 TB hard drive, with over 450 GB free at the start of the recording session, and still well over 430 GB free at the end of the session.
• Running Audacity 2.0.5, the latest version for Windows.
• Recording with an M-Audio FastTrack Ultra 8R USB audio interface. Running Windows 8 pro with all updates applied as of this morning.
• I’m recording live Internet radio streams, played via Internet Explorer, and routed to the M-Audio FastTrack Pro.
• Aside from the background processes, only Internet Explorer and Audacity are running when this happens while recording.
• The audio from IE sounds fine, and things look good in the waveform view in the track display, even after the choppiness starts. This is true during recording as well as in subsequent playback. My hunch therefore, is that the sound is being recorded probably, but Audacity can’t play it properly after 6:45:47.
Observances during recording and in subsequent playback:
• Resource meter shows that about 2.8 GB of memory is used, 5 MB reserved for hardware, 0 MB of RAM is free (this value gradually declines to zero during recording, and hits zero a few minutes before the choppy sound appears), Standby is at around 5336 MB.
• If I stop the recording at around 6:45:30, and then append to it, no choppy sound appears in the appended portion, even several minutes after where it begins when the recording session is allowed to extend past the 6:45:47 time.
• If I append to the recording after the choppiness begins, the appended part is not choppy, but the choppiness prior to that point remains.
There’s a long list of tasks given in the documentation, to free up computer resources for Audacity. But before embarking on that time-intensive path, I wanted to see if anyone here has seen this before, and if so, ask them to respond with how they solved this problem.