How does the ARSC Guide to Audio Preservation separate a preservation transfer from restoration, and what does it say about disc speed and equalisation?

The ARSC Guide to Audio Preservation (CLIR 2015, CC BY-NC-SA 4.0, credited photos excluded) separates preservation from restoration. A preservation transfer reproduces the carrier accurately with aligned machines, the correct stylus and equalization or other decoding as needed. Subjective clean-up is restoration, done only after a preservation copy exists. It defines a preservation master, an access master (which may be restored, e.g. de-noised) and an access copy, and names BWF .wav the de facto archival format. Many '78 rpm' discs should really be played at slightly different speeds (e.g. 76 or 79 rpm), so turntables need incremental speed control. Curator qualifications: Documents read 2026-10-22; nothing transferred or measured. Verified on producer copy arsc (sha256 794a69832ed48120 = pin): 'licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Photos with credits are excluded from license'; 'The Broadcast Wave Format (BWF) .wav file is the de facto standard for digital archival audio'; 'equalization and other decoding mechanisms, such as noise reduction, as needed'; 'An access master may also be “restored,”'; '(e.g., 76 rpm, 79 rp[m])'; 'an option for incremental changes to speed'. Limitations: Documents read 2026-10-22; nothing transferred or measured. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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