Records of various materials are sent to us in different conditions. Some records arrive with cracks across the surface, some with pieces missing from the outer edge, and some arrive warped. Vinyl warps quite easily if is left exposed near a sunny window or left in a car on a hot sunny day. Take care where you store your vinyl and remember if your turntable is near a window replace the record into its dust cover and sleeve after playing and don’t leave the record exposed to sunlight on the turntable.
A customer recently sent me a large crate of LPs to be restored and transferred to CD. One box set, Bach’s Brandenburg concertos, had obviously suffered a fate with sunlight as both LPs were warped along one side of each record.
The first picture here shows the damage (click on the picture for a more detailed view). Playing a warped record in this condition is virtually impossible because at 33 1/3 rpm the forces exerted when the arm suddenly drops and then rises (or on the reverse side of the record, rises and then drops suddenly) throws the stylus out of the groove - not good for the record or the stylus. One method in overcoming this problem is to reheat the vinyl while it is sandwiched between two pieces of glass and this is a reasonably successful method of flattening the record. However a method I favour more is based on reducing those forces of movement and simply reducing the speed of the turntable by half – in this case to 16 2/3 rpm, then recording the material onto a tape machine, we use a Studer A810 and run it at 15ips. This obviously is a lengthy process, all the material takes twice as long as usual to record but the results are well worthwhile.
Once the material has been transferred onto tape, the tape machine can then be speeded up to 30ips doubling the speed and returning the material to it’s rightful speed.
The choice of turntable for carrying out this type of rescue mission is quite critical, we use a high quality deck djs would use in discos or clubs. The Stanton STR8.150 is ideal because this deck was designed with a short straight arm allowing the dj to efficiently carry out “scratching” (manually moving the record forwards and backwards), many standard decks (including some dj decks) cannot handle these sudden forces and, again, the stylus will jump hence the specific design of the Stanton. Therefore this is an ideal deck for playing warped records with the associated forces exerted on the stylus and arm even at slower speeds.
Warped record on deck
Studer A810
Stanton STR8 150
Tags: Audio Restoration, Damaged Materials, Vinyl