A key developer of the CD has died.

[Soundminded]

Sony Global - News Releases - Passing of Norio Ohga, Senior Advisor and former President and Chairman, Sony Corporation

[sq225917]

A sad day, a man with real vision

[c12mech]

I read this earlier. RIP man.

I remember my first cd player. I thought nothing could sound better then that thing.

[mrfeedback]

Why 44.1k sample rate ???.

Eric.

[benb]

Originally Posted by mrfeedback

Why 44.1k sample rate ???.

Eric.

I recall that it's related to NTSC video. There was a consumer (?) device to record digital audio on an ordninary videotape recorder, in the mid to late '70's It did A/D conversion and then conversion to a video signal for recording, then the reverse for playback. I forget the name or if this was made by Sony or who - it was the same format later used in CD. The 44.1k had to do with how many bits it stored in a horizontal scan line and the scan line frequency (15,750 Hz).

CNN's article says he chose the playing time of the CD to hold Beethoven's 5th Symphony, but the legend I heard decades ago was it was his wife who wanted to hear the whole of Beethoven's 5th uninterrupted.

Regardless, he lived to see most of the life of CDs after they replaced LPs as the common commercial music format, a great life's achievement.

[SoNic_real_one]

Originally Posted by mrfeedback

Why 44.1k sample rate ???.

Eric.

At least is not 32k like Phillps wanted...
Why 44.1KHz? Why not 48KHz?

Storing digital audio on a hard drive was impractical, because the capacity needed for significant amounts of 1 Mbps audio was expensive. Instead, they used video recorders, storing samples as black and white levels. If you take the number of 16-bit stereo samples you can get on a line, and multiply it by the number of recorded lines in a field and the number of fields per second, you get the sampling rate.
It turned out that both NTSC and PAL formats (the video standards used in US/Japan and Europe, respectively) could handle a rate of 44100 samples per second. This rate was carried over into the definition of the compact disc.

The sampling rate for "professional" audio, 48KHz, was chosen because it's an easy multiple of frequencies used for other common formats, e.g. 8KHz for telephones. It also happens to be fairly difficult to do a good conversion from 48KHz to 44.1KHz, which makes it harder to, say, copy an audio CD with "consumer" DAT deck. (Well, okay, some consumer DAT decks can do 44.1KHz now, but initially only "professional" decks could handle the lower requency.)

So why 44.1k? - Analog video tape capabilities.
Why 48k latter? To combat the eventual piracy of CD with the new digital recorders (DAT). Thanks Sony for the mess

[benb]

Here's some more info on the "PCM adapter" - all the models listed were made by Sony. The article says these were used in the '80's, but I could swear I read something about this in a stereo/audio magazine around 1978-1979:
PCM adaptor - Wikipedia, the free encyclopedia

[oshifis]

I still have somewhere the service manual of the PCM1610, and I always wondered why Sony used NE5532 throughout in the analog part. Perhaps this partly explains the sound quality of early compact discs.