Where old disc recordings are considered to be of artistic or historic interest, from before the era of tape or where no tape master exists, archivists play back the disc on suitable equipment and record the result, typically onto a digital format, which can be copied and manipulated to remove analog flaws without any further damage to the source recording. For example, Nimbus Records uses a specially built horn record player to transfer 78s. Anyone can do this using a standard record player with a suitable pickup, a phono-preamp (pre-amplifier) and a typical personal computer. However, for accurate transfer, professional archivists carefully choose the correct stylus shape and diameter, tracking weight, equalisation curve and other playback parameters and use high-quality analogue-to-digital converters.