Technical Consultation by Bill Thompson

October 14, 2000

Dea:

This is Bill's consultation. He was totally swamp and apologize for not getting back to you earlier. We hope this will be helpful and a support for your (divine) work. Also if you need more info, get back to us by email. Thank you. Bom Sankar Bholenath. Carol & Bill.

The important consideration when archiving material from analog tapes are:

1) regardless of how carefully they have been stored (in terms of a cool, dry environment) it's crucial to minimize the number of playbacks (preferably one only!) much less rewind/fast-forward operations and they should be played back (for the purpose of digitization) on a well-maintained high-quality (transport and audio) tape deck. As I don't know whether the tapes in question are exclusively analog cassettes or whether (perhaps) some of them are open-reel recordings, it's hard to tell you what specific pre-playback preparation the tapes should receive. That is to say that depending on the manufacturer/formulation/vintage of open-reel tapes, some amount of baking in a low-temperature oven may be required in order to insure the tape doesn't disintegrate on playback. Obviously, this is rarely an option in the case of compact cassettes as the shell likely wouldn't endure the temperature without damage, but careful and minimal handling of the tapes (setting levels for the transfer with "dummy material" rather than the actual source tapes, for instance) is still essential as is frequent cleaning of the tape deck heads and transport parts with 97-99% denatured alcohol in the case of the metal parts and a rubber cleaning solution in the case of the non-metal parts at regular intervals (and after frequent visual inspection) is imperative as some "shedding" of the tapes' backing is inevitable as they're played back. Any of this residue that builds up (and is not removed thereafter) is going to degrade the audio quality, speed stability, etc. of subsequent material.

2) The digital recorder used to capture the recording and specifically it's analog-to-digital converters need be excellent quality (preferably 24-bit, not 16-bit like DAT or CD-R) in order to maximize the benefit of any processing designed to remove tape hiss and other noise components from the audio prior to bringing the material down to the 16-bit resolution required for the final CD masters.

In summation, this is a process not to be taken lightly given the age and import of the material we're talking about as you can easily destroy the original tapes in the process, beyond the mere fact of limiting how "clean" and intelligible the end result can be based on how the digitizing went down.

Bill Thompson