what you can learn from the old digital format (part 1) • Stereo.ru

In parallel with disc players, the portable audio market of the past years was remembered for MD players. Due to the closed ATRAC (Adaptive Transform Acoustic Coding) lossy codec, interest in minidiscs is now minimal. But still, it would be interesting to note a number of features of the MiniDisc and the audio equipment associated with this medium.

Regardless of the technical limitations, the MD form factor itself still arouses deep sympathy, which, to be honest, is even ahead of the vinyl record for my taste. In films about the future, mini-discs appeared as a carrier for all sorts of holograms and other valuable information. And it would be great if the CDs turned out to be something like these neat floppy disks in a hard case.

It’s hard to imagine now, but there was a time when music content was handled without computers. And the mini-disk recorder was indispensable on radio stations and studios in the 1990s: all sorts of jingles, backing tracks and so on.

After all, it was not yet possible to rewrite CDs, swap tracks, mount compilations, etc. And DAT-recorders, in turn, could not provide instant access to the track. All the “plywood” of the stage followed the artists on tour in the form of mini-discs and almost never let them down. Minidiscs were also actively used by audio bootleggers.

The most common component in the studios of the second half of the 90s – Sony MD decks of the “500th” series

The “little brother” of a 64 mm compact disc appeared in 1992, had a similar track pitch and a capacity of 74 minutes, which was later increased to 80. Data were also read and written using a laser. But at the same time, recording on a mini-disk was possible only at the moment of the presence of a magnet on the back of the disk.

The magnetic field recorded the relief of a special coating on a disk heated by a laser to the so-called “Curie point”. After cooling, two types of regions formed on the surface due to different magnetization. Their role in reading, in fact, will be the same as that of the familiar pits and lands on CD. This is how the magneto-optical principle worked. At first, the prices for mini-discs were inhumane, but then they settled down and began to cost no more than $ 5.

By the way, in terms of the number of rewriting cycles, the mini-disk turned out to be very reliable and durable in comparison with CD-RW, in which the tracks are formed by the phase states of a chemical dye. And one more important point: the absence of problems with gapeless playback when Tidal and some modern players shut up at the junctions. Besides, with all the inevitable fetishes of MiniDisc collectors, I have never heard any talk of changing the sound depending on the brand of minidisc, and this is also worth a lot.

Sony made no secret from the very beginning that they wanted to make an alternative not to CDs, but to cassettes. But in addition to the beautiful technical performance, various vexatious moments and housing issues intervened in life. As a result, the rival digital cassette Philips DCC vanished into oblivion, Sony itself fenced off its idea with a cloud of license restrictions in order to lose ground to solid-state iPods and free MP3 in less than a decade. Today, minidiscs are of interest to only a handful of collector fans. Let’s hear what they say.

Top MD deck Sony MDS-JA555ES. Retail $1100 (1999)

The most common thesis: “ATRAC sounds better than MP3”. Some go so far as to say that minidiscs sound even “better, warmer than the original CD”. In principle, this second situation, despite its absurd appearance, is quite acceptable. Compared, as a rule, not abstract formats, but two components with different fillings.

For example, a CD player may have a rotten analog output. And a copy made from it optically on a top-end ES-class MD deck will play better, despite intermediate degradation due to ATRAC compression. Here it is important to note something else.

In contrast to the limited functionality of CD-players of the past, their peers MD-deck can receive and send a signal 24-bit optically. And even now they can play the role of an external DAC, albeit limited by the discreteness of the stream at 48 kHz. To do this, you just need to turn on the pause recording mode.

Characteristically, Sony allowed this to be done even without a disk, while other manufacturers needed a medium inside, which rotated all the time during a pause, wearing out the mechanism. But the relationship between the main license holder and other partners is a topic for a separate paragraph.

Sony kept all the latest ATRAC updates for its players, trading older versions of the codec on the side. Then Sharp, having not received the current latest ATRAC 4.5, indicated its development based on ATRAC 4 with a higher index of 5, and then ATRAC 6.

After that, Sony had to abandon the linear numbering. In the struggle for the buyer, the confusion turned out to be terrible. Well, let’s try to understand the ATRAC hierarchy, at least within the framework of the license holder.

ATRAC officially compresses the original with a ratio of 1:5 and a bit rate of 292 kbps using a psychoacoustic algorithm. The very first generation of ATRAC was really not very perfect and sounded lousy even according to the fans of the format. But by the third iteration of the codec, which appeared in 1995, a significant increase in the quality of coding was achieved. Noises and characteristic metallic overtones are gone. Signal processing was carried out in 20-bit, which Sony increased to 24 bits in ATRAC 4 a year later. And all this was called – Wide Bit Stream. In particular, the MZ-R35 player, which we will consider in the next article, has the fourth-generation CXD-2652R chip installed.

But all these impressive 24-bit figures concerned only the mathematics of ATRAC coding inside the processor. Further, the action of Sony technologies ended, and the role of ADC / DACs was played by Asahi Kasei AK4501-4517 chips, which remained 16-bit even with the advent of the fifth generation of ATRAC, which received the Type-R index. As an example, the following material will also consider the Sony MDS-JE640 fixed deck.

Further development of ATRAC has focused on the development and improvement of the lower bitrate economical MDLP modes announced in 2000. For LP2 and LP4, they were 132 kbps and 66 kbps, allowing you to increase the capacity to 160 and 320 minutes, respectively. Let’s not forget that for audiophiles at this time, Sony was doing DSD and SACD, and minidiscs were used not only for music, but also for podcasts, educational and other speech materials. Home theater veterans should remember the minidisc translations that ran in parallel with the foreign film.

Now it’s time to create confusion not only for Sharp, but also for Sony marketers themselves, who named the new ATRAC3 encoder. The idea was that the old 3rd generation ATRAC should now be read as ATRAC1 v3. But where ATRAC2 went in this case is not very clear. It is said that it was used for SkyPerfecTV satellite broadcasting.

The next Type-S codec combined Type-R and ATRAC3 functionality. It is characteristic that all these updates affected only the quality of the signal packaging. That is, a recording made using the latest ATRAC Type-S could be played on an old MD player. In general, the format remained backward compatible, with the exception of the MDLP mode.

This was the end of the positive news and the hell that awaited the user when trying to transfer content between the mini-disk and the computer began. In the video clips, everything happened quite cheerfully and even with a twinkle, but in real life it looked a little different, to put it mildly.

The old restrictions on copying optical CDs to minidisks could still be understood. In addition, some cheated by turning off the power of the recorder at the end of the recording, until it had time to supply the title of the phonogram (TOC) with blocking marks. But the NetMD system, launched in 2001, can be included in textbooks on sadism. I am neither a sadist nor a masochist, so I would not like to dwell on this savage practice in detail. In short, it will be said that there will simply be no normal, familiar manipulations for copying files via USB, forget it.

Thanks to a silent firewall purely under Windows, the music is transferred (very slowly!) only in one direction and cannot be changed. In addition, it will be converted twice to ATRAC, and not to standard SP, but to LP2 with a low bitrate.

The SoundStage software turned out to be such a “thing in itself” that enthusiasts have not yet created a 100% working plugin for converting and supporting ATRAC audio on other platforms. Who is interested in suffering – welcome here. And we will simply try to push this trauma on the basis of copyright to the periphery of consciousness.

A local businessman shared his impressions of Japanese investors. According to him, it was a completely different experience than with the Anglo-Saxon colleagues, who quickly turned the bait at the first trouble. The Japanese, much more cautious at the stage of mutual sniffing, then stubbornly stuck to the original line, despite the obvious losses of the joint venture. Actually, this observation is confirmed by the final chord of the mini-disk. In the yard – 2004, flash players and iPods, and Sony is launching a completely exotic idea.

Everything has been redesigned in the Hi-MD system, no longer backwards compatible with older MD players. The old Philips EFM 8-to-14 modulation that we remember from CDs has been changed. Now in Hi-MD, code packing is done more densely according to the RLL1,7 method, as on a hard drive. Thus, after formatting, the capacity of the mini-disk increased from 177 to 330 MB. Plus, there are new Hi-MDs with a reduced pit pitch that can hold a whole gigabyte of data. The increased capacity was needed for a reason, because the Hi-MD specification now allowed recording uncompressed PCM 16 bit / 44 kHz.

All Hi-MD lossy encoders have been rebuilt and named ATRAC3plus. Of the old material, only the MDLP modes of ATRAC3 have been preserved. It was possible to roll up 34 hours of audio in Hi-LP format (ATRAC3plus 64 kbps) onto such a carrier. Everything would be fine, but it was no longer possible to play records in Hi-MD on old decks, and NetMD’s sadism has not gone anywhere. An exception to data transfer was made only for the latest 2006 Sony MZ-Rh2 portable recorder, which gained cult status and an insane price on eBay. The autistic picture was summed up by the announcement of ATRAC Lossless (why???), which there was no one to put on – the era of mini-discs was over.

The final Sony Hi-MD Walkman MZ-Rh2 was luxurious and capable of working with WAV and MP3, but that didn’t save the format. Have you ever seen the presidium of Japanese corporations? Try to explain to fifteen grandfathers with a combined age of more than 1000 years who have never sat at a computer why, for example, FLAC and why it is useful to make the audio format codes open.

After all, everything went well in the 60-70s, when the perfection of electronics reached virtuoso heights, while remaining within the framework of traditional material culture. However, the well-known Japanese qualities – perseverance, the accuracy of the master of poppy seed netsuke sculpture, fanatical devotion to the team – turned out to be ineffective in the face of the tasks of the abstract world on the monitor. The technical performance of the mini-disc is still admired today, but it is already difficult to imagine them in new films about the future.

Continued: MiniDisc Remembering: MD Measurements and Tests (Part 2)

Minidisc FAQ / Sound and Acoustics

Teapot Corner

1. I don’t understand anything about minidiscs. Can you explain to me on your fingers?

In terms of functionality, the minidisc is a cross between a CD and a cassette. Like a cassette, you can record from any source on it and play it back through headphones or through your home HiFi system. Like a CD, the data is stored digitally, the sound quality is excellent, and you can always get to the right track almost instantly. Unlike a cassette or CD, you can edit the recorded audio, split it into tracks, rename the tracks, and move them wherever you want.
And, of course, remove what is not needed.

Unless you have a NetMD-enabled device, the only way to transfer audio from or to an MD is real-time recording and playback (excluding special high-speed CD/MD devices). Also, using NetMD or not, you will not be able to download a compressed stream from a minidisk to a computer. This is the main functional limitation of MD and computer MP3 and CD-R players.

2. Is it true that I can re-record to an MD?
I’ve heard that I can burn MP3s to an MD, then listen to them, delete some and add more songs later. This is true?

Yes, that’s true, except that when you burn MP3 to an MD, you must record in real time by playing the files on the computer and recording through the PC’s sound card. This will convert your MP3 to ATRAC (Sony’s audio compression format) on the MD recorder. You can then move, edit, delete and overwrite tracks with the burner as you please.

3. Why should I buy an MD recorder instead of a standard portable CD player, especially considering the popularity of CD-R lately?

Well, if you never need to record with a portable device, the gigantic size of the CD player doesn’t bother you, you like to use your PC to burn new songs every time, and you will never delete or move tracks on the disc – then you should definitely take CD player.

Well, to be serious, it’s up to you. There are many happy users of both MD and CD players. Just think in your mind all the areas of future use of the device.

4. I’ve heard that MDs are getting closer to CD quality and use compression. How good do they sound compared to CD? Can you hear the difference?

When the first minidiscs hit the market, the difference in quality from a CD was clearly noticeable even to an inexperienced user. Today, years later, ATRAC (the compression technique used in minidiscs) has been greatly improved, and now you need sensitive ears and expensive equipment to hear the difference between CD and MD. If you don’t believe me, listen to the opinions of several people, experts in sound and HiFi.

5. How can I transfer CD tracks to an MD?

Using audio equipment: Connect a cable from the headphone jack on the CD player (or line-out) to the line-in of the MD device. The cable is called “mini-jack” to “mini-jack”, and you can buy it at any store. (Recording from a CD player to an MD can also be done using a digital optical cable.)

Using a computer: Connect the headphone jack to the line-in jack of an MD recorder (see above), then start the CD player.

6. Since MDs are digital, why aren’t there MD drives that can be connected to a computer to transfer audio directly between the PC and the MD?

To transfer sound from a PC to MD, Sony has advanced NetMD technology, which allows you to upload sound to a minidisc at high speed via USB. But this is a one-way path, since the data downloaded to the minidisk cannot be read on a PC. They can only be played on an MD player.

As for direct transfer from MD to PC, that would be great! (You can join the petition against Sony). Unfortunately, MDs were designed with the audio/data barrier in mind, which prevents direct access to ATRAC audio data on a computer. This approach is in line with the record industry’s message about preventing piracy. (The fact that the Sony CRX10U-A2 [a portable MP3/CD player that connects to a PC via USB and allows transparent transfer of data from and to a PC] was released does not fit into this model, since CD drives appeared before the act to prohibit the bit-by-bit copying of digital music by the user ).

A year after the introduction of minidiscs, Sony announced MD Data – a set consisting of slightly modified minidiscs and an MDH-10 drive with a SCSI interface. Thanks to this, the user could store digital data on the minidisk. Unfortunately, the drive cannot be used to write or read ATRAC data to an audio MD.

Despite this approach, one company sells a system for direct access to ATRAC data. By modifying the firmware in the Sony MDH-10 drive, EDL in the UK was able to create the Minidisk Transfer Editor, a package that allows direct computer
access to ATRAC data, with the ability to convert ATRAC to .wav file on PC. The system is designed for professionals (radio stations, etc.), so it costs $5,000.

7. Can an MD store information in MP3 or other computer formats?

Minidisc can store audio information obtained from MP3. You can perform a similar operation by playing MP3 on your computer and recording to an MD using the line-out of your sound card.

8. But can I use the MD to transfer MP3s or other computer files?

Regular audio MD is not capable of transferring computer data. However, there is a small offshoot of the minidisk, MD Data, which can store 140 MB of data on a disk (it works exactly like a Zip or floppy disk, but uses MD technology). MD Data discs are not compatible with regular MD Audio discs, so you need to purchase MD Data discs and an MD Data drive separately to transfer computer data to an MD. (The technology was introduced relatively recently, but it can be considered already extinct).

9. Can I record music from the radio?

Yes, connect the headphone jack on the radio to the line-in of an MD recorder

10. Can the MD be connected to a tape recorder or center?

Yes! Via headphone jack or tape recorder line output.

11. I don’t quite understand what kind of cable do I need?

12. How else can you record sound on a minidisc?

Microphones, turntables (works great!), digital recorders, VHS/DVD audio, game music, telephones, electronic instruments, etc. With a normal microphone and cable, you can record anything.

13. Enough about the MD recording. Can I record audio from an MD on my computer (or other audio device)?

If you have the right cable, then yes. You can use the same analog cables that are used to record audio on an MD. Just swap inputs with outputs. On the computer, you should connect the line output of the MD device (mini-jack to mini-jack cable) with the line-in of your sound card. If you are interested in digital audio transmission from MD to computer, then you will have to look for an MD device with a digital input (all portable MD drives do not have this option, but most MD hospitals do), plus you need the right digital cable.

A rather nice selection of software for recording sound on a computer can be found at MusicMatch.

14. Is it possible to perform the same operations on a portable MD device as on a large MD station?

Yes, almost everything. MD stations usually have richer editing options when splitting tracks (so-called “rehearsal mode” with 11ms or 60ms accuracy), and some of them allow you to connect a PS/2 keyboard, which makes entering titles much easier. Stationary devices usually stand out for their improved analog I/O quality (but, unlike portable devices, they usually don’t have a microphone input). When digitally recording from a CD, minidisc portables and stationary devices work the same way. The main difference is that MD hospitals usually have a digital output, while MD portable devices do not.

15. What is the difference between a player and a recorder?

The player only plays MD, the recorder can both play and record.

16. Do portable MD units have a built-in AM/FM tuner?

The only two MD units with a tuner are the Sony MZ-F40 MD player released in May 1997 and the new Sony MZ-G750 MD released in early 2001.

17. I heard that minidiscs are slowly dying. This is true?

Technology is constantly evolving, causing older media to “retire”. MiniDiscs have been in use since 1992, but they have proven to be superior to many competing products (most importantly, they are cheap!). The life cycle of minidiscs will last for at least a few more years.

18. What is the difference between MDs and 3” CD-Rs used in the Sony CD1000 digital camera? In 1998, Sony was selling digital cameras in Japan called the CyberShot DSC-MD1 and recorded photos on MD. What is the difference between burning an image on a MD and on a CD-R?

The MDs and 3” CD-Rs used in the Sony CD1000 are completely different. MD uses magneto-optical recording on a 64 mm disc sealed in a cartridge. CD-R uses optical recording on an open 300mm or 80mm disc. The two formats are completely incompatible with each other.

19. I am interested in technology. If you take the minidisk out of the cartridge and compare it with a CD-R, how will they differ?

One uses magneto-optical recording, the other uses optical recording. In the first case, you need a magnetic head and a laser, in the second, only a laser. The maximum recording speed on a minidisk is from 176 kb / s to 352 kb / s (for example, home hospitals with 4X CD-> MD conversion and Kiosk products). Modern CD drives can write information at speeds
7.1 MB/s (40X) and above.

20. I recorded the sound from the radio on an MD, labeled the tracks, and then digitally copied the MD from the hospital to a portable MD recorder. The sound and track marks were copied, but the track names were not. What’s the matter?

Consumer MD, DAT, and CD devices use the S/PDIF (Sony/Philips Digital Audio Interface) digital audio standard. It transmits sound samples for the left and right channels (at 32, 44.1 or 48 kHz, and up to 24 bits wide), in parallel with some status bits (rights and track information). And while in theory consumer S/PDIF devices can exchange track information (there are unused bits in the data stream [in fact, in S/PDIF “professional” mode it is possible to transfer ASCII information between source and destination]), the transfer of such information is not included in consumer S/PDIF specification, so it is not implemented
in consumer devices.