MiniDisc (Atrac) Spectral and Frequency analyses.

[range_hood]

Here is some kind of version history of the Atrac codec used in MiniDisc devices.
(Which ATRAC chips are in which MD units? minidisk.org faq (http://www.minidisc.org/minidisc_faq.html#_q33), version table (http://www.minidisc.org/atrac_versions.html))

ATRAC-Version (release year) - [bitrate] - {frequency response}
ATRAC1-version 1.0 (1992) - [292 kbit/s] - {15kHz}
ATRAC1-version 2 (1994) - [292 kbit/s] - {18kHz}
ATRAC1-version 3 (1995) - [292 kbit/s] - {18kHz}
ATRAC1-version 3.5 (1996) - [292 kbit/s] - {18kHz}
ATRAC1-version 4 (1996) - [292 kbit/s] - {20kHz}
ATRAC1-version 4.5 (MD-Decks; 1996) - [292 kbit/s] - {20kHz}
ATRAC3-version 1.0 (MDLP) (2000) - [132/105/66 kbit/s]
ATRAC1- DSP Type-R (2001) - [292 kbit/s] - {20kHz}
ATRAC1- DSP Type-S (2002) - [292 kbit/s]
ATRAC3plus (2003) - [256/64/48 kbit/s] - {20kHz/?/?}


Atrac3 (MD-LP)

I found the codec at minidisc.org (http://www.minidisc.org/mdlpfaq.html#_q73). Samples also taken from there.

...
Notes:
.snip.
2. This audio codec was assembled from publicly available bits on the Web and hence may not represent the ATRAC3 codec Sony currently supplies with their MDLP and MemoryStick audio devices. It is supplied for educational purposes only, please address all questions about commercial use and licensing of ATRAC3 to atrac3@<hidden>.

[range_hood]

right channel only.

[range_hood]

DSP Type-R SP

[range_hood]

ATRAC3plus Hi-SP (256kbit/s)

[range_hood]

Atrac1 version 4 (Sony MZ-R55)

[JeanineMcphillips]

Hi

Nice work and thanks for providing history of version of the Atrac codec.
Its really helpful :lol: