Saving a Blues legacy.
The recovery and archiving of the late Colin Cooper’s later recordings in 2011 proved to be a labour of love which took several months of dedicated work. If this had not been done we may have lost for ever this great legacy of British Blues. Having mastered the Big Blues album and remixed a live album for Colin I was delighted to be asked by his son Ben to recover and archive these unique recordings.
The multi track recordings for the final album (Big Blues) that Colin Cooper would record with his Climax Blues Band were recorded by Colin onto multiple ADAT tapes, typically three tapes per song and these were run on three synchronized Alesis ADAT XT digital 8 track recorders which allowed 24 multi-track recordings. During the recording phase the speed of some of these tapes had been altered which resulted in tempo and pitch charges to a number of the recorded tracks. This required some trial and error to re-adjust on replay in order to reverse the effects and bring the affected instuments back to match with the other recorded tracks.
Due to the storage conditions the ADAT tapes had badly deteriorated. The binder (adhesive) which held the magnetized oxide onto the tape had seeped out along the edges of the tapes and had glued successive loops of the tape together at the edges. As if that wasn’t problematic enough the leaked binder also had a healthy deposit of mould growing all over the top and bottom faces of the spools of tape.
The tapes are in sealed VHS style cassettes and the tapes are played inside the ADAT recorder which meant that they could not be seen when playing back. It soon became evident that the tapes were snagging as a result of the successive loops being glued together, this resulted in the tapes tearing in much the same was as you would tear a piece of sticky tape off the roll. The first strategy was to run the tapes though once at the slowest speed the ADAT recorder would allow in order to separate the stuck together tape and also dislodge the mould. This however still resulted in the tape sticking and tearing.
In order to save the tapes it was clear that a new strategy was required. The final solution was to remove the screws from the cassette shell and take off the top half of the shell (the half with the windows) and carefully and very slowly turn the tape spools manually with a pencil which was inserted into the splines of the spool wheels on the underside. Whilst turning the spools carefully prising the stuck edges of tape apart for each of the 40 minute ADAT tapes. This took quite some time as there were 40 ADAT tapes to go through. Once the tapes were separated and the mould had been carefully vacuumed out of the cassette shells the shells were reassembled and run through the ADAT recorder and the output recorded onto computer using MOTU Digital Performer. Even after the care taken to this stage there were still quite a few tapes that ripped and had to be repaired. In addition, the ADAT player had to be frequently cleaned to remove the remaining mould that found its way out of the cassette shells.
In order to repair the tapes the cassettes had to be re-opened and the broken ends of the tape pulled out and matched up taking care to ensure the magnetized side were together. The thin tape had to be held down with a small weight and the ends matched up. Not having traditional tape splicing tape to hand I used thin brown parcel tape as I knew that this had a very thin but strong coating of adhesive, much better than the usual sticky tape which itself leaks adhesive at the edges more than the brown parcel tape. Having used this previously to repair ADAT tapes I was happy to use again as it was unlikely that the tapes would be used again after recovery of the recordings. I would carefully place a wide piece of the brown tape over the matched up ends of the broken ADAT and gently smooth out any air bubbles then trimming off the excess each side of the recorded tape with a model makers scalpel knife. The tape was then repaired. Having then reassembled the repaired tape and cassette shell the recording into the computer continued one tune at a time until the tape tore again.
The sound, which is digitized as a binary series of 0’s and 1’s covers very small areas on the tape with this data. A break in the tape, no matter how carefully repaired will result in a glitch in the data flow and this can manifest itself in the replayed recording as signal dropout or worse, loud clicks as the digital converters try to make sense of the broken data stream. This then required some judicious digital sound editing to remove. Using Digital Performer and BIAS’s Peak Pro sound editing software, clicks were removed or entire individual notes were copied and pasted in from other parts of the tune where the de-clicking wasn’t successful.
Following the sample rate conversion from the recorded 48Khz to the CD standard of 44.1kHz the recordings were then grouped and numbered into the sets of tapes which were used in each of the recording sessions. The final cleaned tracks were then copied as data files onto recordable DVD discs as these had sufficient capacity to hold the 40 minutes x 8 tracks of each ADAT tape. Two further copies of the DVD’s were recorded as back ups.
Further stereo live recordings required the use of a borrowed mini disc player but this process was far less problematic than the transfer of the ADAT tapes.
Clive Spencer, 7 December 2013.