ABSTRACT
This chapter deals with the differing requirements for reproducing discs, or indeed cylinders, that are not made to the microgroove standard. Early discs used a wide variety of equalisations and so an archival phono preamplifier must be able to provide all these in an accurate manner, though there is no need for great economy in specialised equipment that will only be made in very small numbers. Although the media involved is always monaural, a stereo cartridge is normally used for transcription, and archival preamplifiers are likewise stereo, with a facility for summing varying proportions of the channels to create a final mono output. The preservation and distribution of archival material in analogue formats requires that it be replayed with the highest quality attainable and converted to digital. The major electronic problem is replay equalisation. Forget about having one universally-accepted equalisation, like the RIAA characteristic for microgroove discs.
