At Lost Sounds we receive many acetate discs from private collectors, as well as record companies, requesting the discs be restored and converted into a digital format. For most private collectors this is usually onto a CD and for our commercial clients the request is often to 24 bit/96 kHz. But many readers and followers of this blog may have never seen or touched an acetate.
Acetate discs were cut as a pilot or reference disc for artists and production staff to gauge how the material would sound once transferred to disc, could the bass be held at the recorded level, did the stereo image transfer satisfactory, how does the material sound on a variety of decks and playback equipment. So an acetate was usually the very first cut of an artists material and may not even resemble the final versions that were then made commercially available.
Physically an “acetate” is far more rigid than a vinyl disc, it is manufactured with an aluminium core (the metal can be see on the edges and in the hole), which was then coated with nitrocellulose. Often they are 10″ (7″ singles were also cut onto this size disc) or 12 “, however we have also handled a few 7″ acetates.
Acetate
The example shown in this picture is a 12″ acetate with only 2 tracks playing on the EMT deck . The material was a rare early 1960’s recording of Dave King and Glen Mason singing two songs together. As is often the case the B side was blank.
Acetate discs are less robust than vinyl, they were never designed for multiple plays, therefore many, today, carry high surface noise and because many have been used in a commercial environment they have not had a great deal of TLC! After a lot of work restoring this disc the material was transferred to CD for a private collector.
It is important to note that when wet cleaning an acetate do NOT use the method outlined below which is specifically for vinyl discs. Applying an alcohol based chemical to an acetate or indeed a shellac pressing could seriously damage the surface therefore great care should be taken. If your acetate discs need to be cleaned use a photographic wetting agent heavily diluted in de-ionised (distilled) water, if the disc is marked with finger and/or hand prints make sure the de-ionised water is warmed to just above body temperature this will dissolve the grease. Use a soft cloth, as for vinyl, and rinse thoroughly in plenty of de-ionised water then leave the discs to dry for some hours before playing.
Tags: Audio Restoration, Damaged Materials, Decca Recording Studios