Many reasons, just a few:
IV.10 Records that have been fully cleaned can still sound – for want of a better term – bad; clicks, pops, hiss, and distortion. There are any number of reasons such as following, but no amount of cleaning is going to fix these physical defects.
IV.10.1 For new records: Poor recording.
IV.10.2 For new records: Problems with the stamper. The stamper prepared during the plating process may have defects. It may have been prepared dirty so that the surface has the impressions of very fine/microscopic particulate. The stamper may have been overused and is now deteriorated and/or shedding metal particles that are embedded in the record.
IV.10.3 For new records: deficiencies with the record formulation. As previously stated, repressed material may not have the same qualities as virgin material. The material blend can be out of tolerance leaving the record with an inconsistent surface. This may be the source of the common incorrect theory that new records need to have the ‘mold release’ removed. Evidence of oil-splotches is the result of poor record formulation.
IV.10.4 For new records: deficiencies with the pressing. Incorrect pressing heat, pressure and time can leave un-filled areas. Incorrect pressing cooling and time can result in material pulled during separation leaving microscopic defects. Note: It is not uncommon for a clean new record to sound noisy for the first few plays. This is not uncommon. There are often microscopic burrs left from the pressing process, and the first few plays essentially ‘burnish’ the surface, removing the burrs.
IV.10.5 For new and used records: Obvious deep scratches. Very light surface scratches are often of no consequence. For used records, many light surface scratches may indicate use of once popular automatic changers that could play a stack of many records.
IV.10.6 For used records: Groove damage such as trenching from many plays with conical and elliptical stylus. Groove damage can also be from an over-worn stylus. In this case the stylus carves/chisels away the side-wall ridges. However, Shibata and other advanced profile stylus can sometimes bridge the trench made by conical and elliptical stylus. However, damage caused by Shibata (or equivalent) is likely “terminal”.
