There has recently been some discussions of repairing a broken or cracked record. Everyone seems to have their own pet solution to the problem of making the record play again, some come close, but none provides a fully restored result.
For some time, I have been intending to post an example of using CEDAR processes to restore a broken record and here it is.
This one is seriously cracked, but the process for a fully broken disc is essentially the same... get it into a playable condition and use computerized de-click and de-thump processes.
The source disc is a 10" American Record Corporation No. E 587 issued around 1930, for theater use.
Love, You Funny Thing! - Imperial Dance Orchestra
See label photo here: http://www.audio-restoration.com/CIMG4743t.jpg
It was recorded at 33-1/3 rpm, transcription style inside start, with the same tune on each side. The disc has a large 1/2 moon crack in it with one end still intact, but hold it up to light and you can see light through the separated end!
See surface crack here: http://www.audio-restoration.com/CIMG4746t.jpg
See entire crack here: http://www.audio-restoration.com/CIMG4747t.jpg
Reasoning was, they were played by the projectionist to synchronize with showing of a silent film. Being shellac discs, and with the heavy weight of the pickups and steel needles, the discs wore out very fast. As one side became noisy, the projectionist would order a new disc and start using the remaining good side.
One pass used CEDAR de-clickle to remove the leading impulse clicks. The remaining thumps were removed using CEDAR de-thump installed on SADiE 5 workstation.
The two audio files can be lined up to see there is no timeline discontinuity as there would otherwise be with conventional physical editing.
Here is the de-clicked file prior to de-thump being done:- http://www.audio-restoration.com/arc-e587-thumps.mp3
Here is the finished de-thumped file:- http://www.audio-restoration.com/arc-e587-dethump.mp3
... Graham Newton
-- Audio Restoration by Graham Newton, http://www.audio-restoration.com World class professional services applied to tape or phonograph records for consumers and re-releases, featuring CEDAR's CAMBRIDGE processes.