DOL, Jazz Images, Waxtime etc.

Short Digital Primer: musical instruments generate PHYSICAL pressure waves, which listeners hear. Microphones capture and tape recorders transform those pressure waves into an electronic voltage signal stored on magnetic tape, we call ANALOG. Those analog signals can be transformed into binary data stream of zeros and ones stored on a disk-drive, we call DIGITAL.

In the 1980s, entering the digital era, PCM encoding – Pulse Code Modulation, became the industry standard for sampling, electronic storage and transmission of audio data. It’s worth a shallow dive to understand the technology.

PCM converts the amplitude of an analogue signal into binary code.

PCM digital data lends itself to near-unlimited digital processing of audio information: compression and limiting (in common with vinyl), quantization (filling gaps between samples), high and low pass filtering, eliminating those pesky top frequencies “we can’t hear”, dithering, sound envelope shaping, white noise remapping, frequency boosting.

An example of signal processing, in which low gain signal  (a quiet bit)  has noise added, to cover up other digital artefacts.

Finally, the processed PCM file can be output to any digital audio output format: to CD (WAV or AIFF), reduced file-size for streaming (MP3), and most important, remastering for acetate cutting, to fit the physical requirements and limitations of vinyl. Derivatives of PCM files are also the bootleggers undeclared source for unofficial reissues.

Modern equipment  today can record digitally in much higher resolution, store more information, even process it to advantage (boosting db of selective frequencies), but sadly, it can not go back in time. The sound quality is only as good as the source capture in 1993. What was lost transferring the original analogue tape to the  audio-workstation PCM conversion is lost forever. 

In the case of missing original tapes, this is where a lot of our music legacy rests. Not the “Which is best, analogue or digital?” Hoff-men argument, but for some music, it is digital or nothing. 

Back to the bigger picture of the “vinyl renaissance” and its Hype Stickers – First time on vinyl! 180-gm audiophile!,  Limited Edition! From the original tapes! – Audio Window Dressing, strangely, usually no mention of sources.

I have done another of my thought-graphics … simplified for clarity, over-simplified maybe. There are many other variations, like needle-drops, but this sums it up for me the ways in which original recording tapes connect to vinyl, throw your own spanner in the works if you like 

Everything is “from the original tapes”, but only a select few are mastered from the original tapes – the All Analogue process (AAA). Over the decades, the source of vinyl reissues became copy analog tape, notably, most overseas edition such as Japanese pressings. They were still in a sense All Analogue, but with an intermediate tape generation step down (AAA). Then in the mid-80s, with the arrival of the compact disc, the music world entered the digital era and the new musical ringmaster, the digital audio engineer. 

The ease with which digital files can be transferred to vinyl – Analogue> Digital> Analogue (ADA), officially and unofficially, is evident everywhere on the Hype stickers, and the vinyl reissue industry depends commercially on audio window dressing (AWD). Funnily enough, in the 90s, record companies were boasting records were digitally mastered.

An engineers guide how to improve recordings digitally: digital transformation and t-polishing. You may ask, why is it necessary? Just because you can doesn’t mean you should.

A lot of the The vinyl reissue industry is hoping no one will be aware of the intermediate digital stage, or what has been done to the recording. 

 from http://londonjazzcollector.wordpress.com/2023/01/20/pharoah-sanders-tauhid-1971-universal-jazz-germany-2022/