Techy - Notes on Playing Back 78 RPM Records with a Magnetic Phono Cartridge
Magnetic phono cartridges are capable of far more accurate sound reproduction than the crystal or ceramic cartridges used at the time 78 RPM records were still being produced. They also track the groove very accurately even at very low tracking pressures, causing dramatically less wear of the record.
Because of this, and because your turntable is likely equipped with a magnetic cartridge, it is important to understand the following:
1. The tip size of the diamond stylus (“needle”) that plays the groove in 78 RPM records is several times larger than the one used for the 33 or 45 RPM vinyl (“microgroove”) records made since the 1950’s. The 78 RPM tip will not fit in a 33/45 RPM disc groove, and so cannot be used to play them. Conversely, a stylus made for 33’s or 45’s will not properly fit in a 78 groove, and can even be damaged if an attempt is made. At best, the playback will be distorted and extremely noisy. Always use the correct size stylus for the appropriate record.
2. If you use a record changer, be aware that most record changers operate the changer mechanism with the same motor that drives the platter. As such, the changer speed will increase when the platter speed is increased. At the 78 RPM platter speed, many changers cycle at a fairly frenetic pace.
Magnetic cartridges have relatively delicate stylus assemblies, and should never be dropped or lowered abruptly onto the record, or damage may occur. If your record player or changer does not have damped cuing or otherwise does not lower the tonearm gently during the change cycle regardless of platter speed, always lower the arm manually to prevent such damage from occurring rather than allowing the player to do so automatically.
3. 78 RPM records tend to be made of material that cracks or breaks easily on impact. As such, it is recommended that record changers not be used unless they drop the record gently, a very rare attribute. Best record longevity will be gained if the records are played manually, one at a time.
4. Even if the record condition is immaculate, the physical material that most 78 RPM records are manufactured from is inherently much noisier than vinyl, and so that will be heard on playback. This is normal, and is simply a limitation of the medium. An accurate cartridge will play back both the music and any noise on the record surface more accurately.
5. Avoid playing records with cracks or deep gouges in the playing surface, or the stylus may be damaged. If the material on the record is rare and/or valuable, consider the services of a professional to transfer the recorded contents to a digital medium such as a CD.
6. Do not clean 78 RPM discs with record cleaning fluids designed for vinyl records. These cleaners typically contain cleaning chemicals that are harmless to vinyl but can seriously damage the material used to make 78’s. Special cleaners for vintage and antique discs are available from vendors who cater to the vintage record collecting hobby / profession. If in doubt, dry clean your records with a soft brush and/or cloth only.
7. Be sure to use the correct level of tracking pressure for your cartridge and tonearm. While vinyl 33s and 45s can be tracked as low as 1 or 2 grams of pressure, most stylus assemblies designed for 78 RPM record playback will track at 3 to 7 grams. Setting the pressure too low will cause increased distortion or even groove skipping and much greater record wear from the mistracking that will occur. Of course, do not set the pressure higher than the maximum the stylus manufacturer recommends. If possible, have a professional turntable service shop check or calibrate this setting for you. Match the anti-skating setting (if present) to the tracking pressure unless told otherwise by a technician who has adjusted your player using test records and instruments.
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