5.2.10 Time Factor A complex transfer may easily take 20 hours for 3 minutes of sound (a ratio of 400:1). An average transfer may take 45 minutes for 3 minutes of sound (a ratio of 15:1), which represents time spent on finding the correct settings for the equipment and choice of stylus, based on an analysis of the recording as it relates to others of its time and storage history. Some experienced archives suggest that, for the transfer of unbroken cylinders in average condition, two technical staff, (one expert and one assistant) can transfer 100 cylinders per week (a ratio of about 16:1). Obviously experience will improve both the ratio and the ability to estimate time required. Digitisation can seem expensive and labour intensive, requiring a great deal of equipment, expertise and man-hours to transfer audio and create all necessary metadata. However this initial front-loading of effort and resources will be offset by the long-term benefits and savings of retaining a well-managed digital mass storage repository, greatly reducing future costs of access, duplication and migration. Note that a crucial factor here is the maintenance of the repository, discussed in detail in chapter 6 and elsewhere. The extraction of the optimum signal from the original carrier, as defined in this chapter, is a vital component of this strategy.