Preservation and Restoration of Analog Recordings

The trend today in media distribution is the utilization of digital assets. However, recording artists, record labels and distributors should be aware of the importance of maintaining the purity of their original analog recordings. As analog to digital conversion technology improved through the years, content owners have gone back many times to their original recordings to create better and more detailed releases for the buying public to enjoy.

Of primary concern, analog recordings on tape should be stored in a climate control atmosphere with a temperature of 60 to 70 degrees Fahrenheit and humidity levels of 40 to 50%. Any extreme temperature variations cause problems with the integrity of the storage masters. Tapes and should be stored vertically on edge using metal shelving and standard tape boxes that contain a center hub. Storing your masters in this way will maintain equalized gravitational force and minimize long-term physical distortions of the medium.

Paper leader is an evil culprit of stored analog tapes and should be replaced with plain plastic leader on all original masters. The paper later will dry out over time and physically distort the adjacent layers of audio tape, causing wows and flutters in the playback.

At our mastering and production studio, The Music Lab, we have often played back master tapes from the dawn of tape recording (the late “40s and early “50s) and we are astounded at the sound quality of these masters. Some formulations from the 1980s and 1990s however, have not fared as well due to a loss of lubricants over time. These tapes will actually stick to the playback heads when played and make screechy sounds. When a tape exhibits this type of behavior, it must be removed from the machine immediately and baked in a convection oven at low temperature for a period of many hours. After transferring the tape to digital, the master should be stored in a flat wound condition. This requires rewinding the tape at low speed so it packs uniformly for long-term storage.

Digital transfers of analog masters should be done using high-quality analog-to-digital converters at high sampling rates. A 24 bit word length should be used for maximum dynamic range.

It is essential that all digital files be stored in at least two locations. This duplication of data will protect the assets in the event of physical disaster or digital errors.

We hope these guidelines will help content owners protect their valuable assets. Proper restoration, storage and preservation of valuable analog recordings will protect them for future generations to enjoy.