63 replies to this topic

[MDietrich]

My first post here... hope it´s in the correct forum. If not feel free to move it around.

I have been reading here a lot lately, my fascination with MD seems to have returned after abandoning it in 2001 for PC based audio.

For years after first reading about it I have been curious about Wide Bit Stream and equally curious if my MZ-R 30 would be able to record in 20 Bits. Turns out it can - only from the digital input of course.

I´ve written an article about this, complete with measurments and stuff: http://marlene-d.blo...c-wide-bit.html

I´d like to have some input as well as experiences someone else has made with other ATRAC versions like 4.5 Type-R.

The MZ-R 900 will be featured in the next article, but I can already tell you that it´s equally Wide Bit Stream capable.

Wide Bit Stream - is that even interesting today, with Hi-MD and all??

[sfbp]

It has come slowly to our consciousness here (speaking for myself - others can argue the point if desired) that one of the big pluses of the MD format is its 24-bitness. I myself was hung up on the ability to get 16-bit "pure" CD sound by uploading with the amazing MZ-RH1, or before that using TOSlink optical. But, just as you say, the internals of the ATRAC format have been (since well before I got into the format some 10 years ago) 24-bit floating point.

This raises an interesting question when uploading from "standard" MD's, as there is a choice in Sonic Stage of generating 256kbps HiSP format (Atrac3+) or 1411kbps CD format (like WAV). Interestingly (?) the 1411 PCM format stored in the .oma container is NOT ATRAC- like in any way, shape, or form. Strip the ea3 header (like ID3) off it and it's just a wav file, 16-bits. Sound Forge refuses to work with LPCM .oma files - you have to turn them into standard WAV files first. (presumably because this format violates the rule ".oma means ATRAC").

I had always (at first) gone straight to WAV because:

a. I had an editor that could manipulate that format
b. I believed that somehow, magically, LPCM was better than Hi-SP.

But now with Sound Forge there's an editor that will work with ATRAC (Sound Forge 9 and later), provided the files have been decrypted with the File Conversion Tool supplied by Sony. So I am currently experimenting with uploading from 292kbps to HiSP (256kbps A3+) instead.

The other part which may be interesting to you is that when transferring LP2 and LP4 formats to the PC (using USB), they are bit-for-bit copied with no conversion whatever, at least by default, it's an option in Sonic Stage. So a well-compressed ("well" as in "it worked nicely and the result sounds good") MDLP recording can be and should be kept as is, unless you want to make CD's from it, which is kind of a waste of space. I think Sound Forge keeps things internally as 24-bit when editing ATRAC files, too.

Just by way of completeness the Atrac3+ formats on HiMD are (or at least, can be) all transferred without conversion. But you quit MD before they got invented HiMD, so I didn't add anything on that.

Your post (and my experience) does, however, explain the observation of the "magic" of MD where a 292kbps signal can recreate what's on a CD. It's not surprising that there's enough information in the 24-bit format (after Sony's throwing away the inaudible stuff) to generate a quite realistic CD. It also leads to understanding of the "warmth" of the MD sound - especially when recording from analogue sources. I'm not sure that this is true for TOSlink, but your experiment may show that it happens with digital input too.

The only missing piece for me, is that I do not own one of the decks which directly outputs 20 (or 24) bits to TOSlink (or coax) for playback into a modern 24-bit capable receiver. These are relatively few, although the MDS-JB940 in fact is fairly readily available. The subsequent JB980 actually removed this feature, as I found out too late, after purchasing one.***

It intrigues me that you mention that 320kbps MP3 is actually 32-bit floating point. I know that Sound Forge 9 sees my 256kbps mp3 files as 16-bit.

Stephen

*** Now - if you, or someone else could tell me how to modify the JB980 to have 24-bit optical output that might be an interesting project indeed!!!!

[MDietrich]

It has come slowly to our consciousness here (speaking for myself - others can argue the point if desired) that one of the big pluses of the MD format is its 24-bitness. I myself was hung up on the ability to get 16-bit "pure" CD sound by uploading with the amazing MZ-RH1, or before that using TOSlink optical. But, just as you say, the internals of the ATRAC format have been (since well before I got into the format some 10 years ago) 24-bit floating point.

(...)

It intrigues me that you mention that 320kbps MP3 is actually 32-bit floating point. I know that Sound Forge 9 sees my 256kbps mp3 files as 16-bit.

Stephen

*** Now - if you, or someone else could tell me how to modify the JB980 to have 24-bit optical output that might be an interesting project indeed!!!!

I have not yet worked with Hi-MD - and I think I won´t considering that 24 Bit capability has been dropped... I also have not tried the MDLP capability of the MZ-R 900 yet. I plan to purchase a used NetMD recorder, just to find out how it works and if there´s a way of transferring the high bit files from MD to PC. I just don´t want to place the Kenwood all the time near my PC , it´s too big for that. Well, I won´t do this normally, I did it just for the article. BUt it´s nice to know that my digital amplifier (Sony STR-DB 830) will receive a 20 Bit signal (it can process up to 24/96).

And I´ve also tried Sound Forge 9.0 and its ATRAC feature. But it won´t convert to 24 or 32 bit fp when converting back, I also cannot use the classic 292 kBit/s bitrate (I tried because I wanted to find out how it sounds without copying from my PC to MD and back)

MD decks outputting the 20/24 bit are rare... I suspected that much since it doesn´t make much sense for a home component to put out this bit depth - many people wouldn´t know what to do with it would they be aware of it. That´s why it´s so surprising that the Kenwood can do so. Does the JB980 have an option to configure the digital output? The older ES recorders had such an option if I´m not mistaken (the MDS-JA 50 being the first). Other than that I have no idea.

BTW, you are re-converting from ATRAC 292 to ATRAC3+? I wouldn´t do that if I were you. I would go the way you used to before - imagine, you are converting from one lossy format to another. I suspect there is a decoding step inbetween so you´ll loose quality. It´s similar to when people are converting from mp3 to mp3 - only with different bitrates. Or did I miss something?

And yes, mp3 just like every other codec (AAC or OGG) is 32 bit floating point. Sound Forge only decodes it to 16 Bit (similar to iZotope RX or WaveLab and countless other software or hardware) but Illustrates' converter dBPowerAmp has an option to put out the pure floating point data (with mp3, AAC and OGG). It´s ironic but one could easily convert to mp3 from SACD or DVD audio and actually keep the resolution! Funny thought, isn´t it?

I´m so glad I re-discovered this little hobby... the MD was great, wasn´t it?

[sfbp]

HiMD most definitely did not get rid of 24-bit.

My point is that 292->256 keeps the 24-bitness, whereas 292->1411 gets rid of it.

[MDietrich]

HiMD most definitely did not get rid of 24-bit.

My point is that 292->256 keeps the 24-bitness, whereas 292->1411 gets rid of it.

Ah, I understand. Thanks for the info. HiMD didn´t get rid of 24 Bit? I assumed that since they dropped 292 ATRAC. Sorry...

[sfbp]

Sounds like you have the tools to check, anyway. HiMD is a terrific format. I suspect the reason Sony is so protective of it, is that they licensed some patented part of the compression (whatever is an advance on Dolby, which they had to pay the customary fees for the Double-D symbol) to some major players. You may not know, but Atrac3+, the format used, is the 2-channel version of something they called Atrac-X - which is designed as a multi channel format.

Sony makes it clear in almost all its documentation that they consider Atrac3+ to compress about 2x as much as ATRAC3. That is, for half the bitrate (relative to ATRAC3) you get similar performance.

[MDietrich]

Sounds like you have the tools to check, anyway. HiMD is a terrific format. I suspect the reason Sony is so protective of it, is that they licensed some patented part of the compression (whatever is an advance on Dolby, which they had to pay the customary fees for the Double-D symbol) to some major players. You may not know, but Atrac3+, the format used, is the 2-channel version of something they called Atrac-X - which is designed as a multi channel format.

Sony makes it clear in almost all its documentation that they consider Atrac3+ to compress about 2x as much as ATRAC3. That is, for half the bitrate (relative to ATRAC3) you get similar performance.

I´ve read about that. With ATRAC3+ they use something similar to HE-AAC which uses Spectral Band Replication which means that frequencies from a certain point are artificially generated by the decoding circuit. If I´m not mistaken I mean... and ATRAC-X seems to be an extension of the ATRAC3 codec, enabling it to perform scalable bitrate streaming and multichannel. But it´s all moot since they appear to have stopped development.

BTW, I have seen in your signature that you own an R50. How good is that unit? I´ve read so many good things about it... does it sound better than the R30? The service manual for example clearly states that all parts used for the R50 are the same ones used in the R30. I´m asking because I might get one tomorrow or on Monday - and I can´t wait

[sfbp]

I got it because everyone told me it's a "must have" and someone here put one on Craigs for $40. I haven't used it much as for portable listening I need more than 80m. But it's a very nicely built machine, solid as a rock, and interesting features. Needs the right remote though, I found an RM-MZR55 which is close enough - the one I was "bequeathed" had no remote.

For parts/rebuilding/repair/replacement, Jim Hoggarth's your man. He's here on the board, been a bit quiet lately but usually lurking there somewhere. He's in England, I think you mentioned you are in Germany, despite signature, so not too much hassle to and from Yorkshire if you need some help, or bits and pieces.

I can't answer about the R30 as I never owned one. Many different people have said that the R50 was the best Sony made, after that some things went downhill. There's an old article from a repairer on minidisc.org that talks about how much better built the R50 is than the immediately following R55.

Speaking personally, for serious recording projects involving line in, I prefer decks. Sony went the extra mile to clean up the inputs, I think. That's not to downplay the R30/50/55, just my preference.

[MDietrich]

I got it because everyone told me it's a "must have" and someone here put one on Craigs for $40. I haven't used it much as for portable listening I need more than 80m. But it's a very nicely built machine, solid as a rock, and interesting features. Needs the right remote though, I found an RM-MZR55 which is close enough - the one I was "bequeathed" had no remote.

For parts/rebuilding/repair/replacement, Jim Hoggarth's your man. He's here on the board, been a bit quiet lately but usually lurking there somewhere. He's in England, I think you mentioned you are in Germany, despite signature, so not too much hassle to and from Yorkshire if you need some help, or bits and pieces.

I can't answer about the R30 as I never owned one. Many different people have said that the R50 was the best Sony made, after that some things went downhill. There's an old article from a repairer on minidisc.org that talks about how much better built the R50 is than the immediately following R55.

Speaking personally, for serious recording projects involving line in, I prefer decks. Sony went the extra mile to clean up the inputs, I think. That's not to downplay the R30/50/55, just my preference.

I have the same feeling that newer recorders are somewhat... fragile. The MZ-R 900 I own for a few days now has a marvellous finish and build quality. But it´s so small and tiny that I´m afraid to break it all the time. The tiny size has another disadvange: it will move by itself. The R30 is heavier and bulkier but doesn´t seem this fragile, it just feels more robust. Boy, the drive from the R900 is loud (normal noises but loud). And the MDs I record with it pose problems for the Kenwood DM-5090: with R900 recorded discs it jumps between titles or skips them entirely by playing the next. The R30 plays these discs without error (I cannot even hear the drive behaving strange like the one on the Kenwood at the same places). I think that the Kenwood starts to break... well it hasn´t been used for years and is constantly exposed to cigarettes. And I´ve just encountered an error with my R900: during titling some tracks it suddenly said that it´s full and cannot except more characters. I had to disconnect power and remove the battery. Now it behaves perfectly again.

But even when considering its tiny size - gosh, the R900 sounds gorgeous. It´s in fact one of the best sounding portable players I´ve ever heard. And thanks for the information on the R50 - can´t hold my horses to finally look at it and touch it... I wanted to own when it was released in 1997. Now I hope I can!

[sfbp]

I think you may find that the next generation of portables with MDLP, the ones with Type-S DSP chip, basically N510/610/710/810 will bring LP2 reproduction back to where you are (at least for portable use) with the 900. Having never owned one (a 900), I cannot be definitive on this point. There's folks who swear by the 909, too. I haven't done the "acid test" SP vs SP between Type-R and Type-S, except with decks - and there are probably other factors there since I use optical out with Type-R and it sounds great going into a 24/192-capable receiver. Sony did keep on improving the audio precision and performance, especially with regard to power consumption, as you would expect, with later models.

[MDietrich]

I think you may find that the next generation of portables with MDLP, the ones with Type-S DSP chip, basically N510/610/710/810 will bring LP2 reproduction back to where you are (at least for portable use) with the 900. Having never owned one (a 900), I cannot be definitive on this point. There's folks who swear by the 909, too. I haven't done the "acid test" SP vs SP between Type-R and Type-S, except with decks - and there are probably other factors there since I use optical out with Type-R and it sounds great going into a 24/192-capable receiver. Sony did keep on improving the audio precision and performance, especially with regard to power consumption, as you would expect, with later models.

What´s the acid test? I´ve never heard of it... assuming something to do with castagnets?

[sfbp]

Acid in the sense that all other factors are eliminated. Perhaps my mis-use of a metaphor.

[MDietrich]

Acid in the sense that all other factors are eliminated. Perhaps my mis-use of a metaphor.

Ah, I see. Do you know music that´s able to trigger errors with ATRAC 4.0 or higher? I´d be very interested... I might own one or two examples myself.

BTW, the review for the R900 is online: http://marlene-d.blo...y-mz-r-900.html

It turned out to be a two-faced bit** when it comes to sound... strange.

[jim.hoggarth]

For parts/rebuilding/repair/replacement, Jim Hoggarth's your man. He's here on the board, been a bit quiet lately but usually lurking there somewhere. He's in England, I think you mentioned you are in Germany, despite signature, so not too much hassle to and from Yorkshire if you need some help, or bits and pieces.

Still here Stephen, just lurking as you say. Not a lot to respond to recently....

Jim

[MDietrich]

Ah, I see. Do you know music that´s able to trigger errors with ATRAC 4.0 or higher? I´d be very interested... I might own one or two examples myself.

I´m used to forums and now I forgot one of the essentials: the search function. Stupid me... but now I have found something

[sfbp]

BTW, the review for the R900 is online: http://marlene-d.blo...y-mz-r-900.html

Sorry for slow turn around here - I just noticed something odd in your article linked above.

The S/N and dynamic range you measured (for the Kenwood DM5090) are at least 18 dB better than Kenwood's own specifications. Seeing as this is not even considered to be a "pro" unit, and Sony's very best (recall that Sony invented the technology and others merely licensed it) figures are for the MDS-JA555ES, which this still beats by almost 2 doublings ie 12 dB, I am forced to consider one other conclusion: namely that your measurement methodology is failing at these extremely low (or high, depending on your view) figures.

I'm not trying to shout you down; merely a polite question as to whether it's possible that these numbers are not real. Somewhere you note a discontinuity in your expectations with the R900. Could it be that the method of measurement doesn't quite stand up?

Cheers

Stephen

[MDietrich]

Sorry for slow turn around here - I just noticed something odd in your article linked above.

The S/N and dynamic range you measured (for the Kenwood DM5090) are at least 18 dB better than Kenwood's own specifications. Seeing as this is not even considered to be a "pro" unit, and Sony's very best (recall that Sony invented the technology and others merely licensed it) figures are for the MDS-JA555ES, which this still beats by almost 2 doublings ie 12 dB, I am forced to consider one other conclusion: namely that your measurement methodology is failing at these extremely low (or high, depending on your view) figures.

I'm not trying to shout you down; merely a polite question as to whether it's possible that these numbers are not real. Somewhere you note a discontinuity in your expectations with the R900. Could it be that the method of measurement doesn't quite stand up?

Cheers

Stephen

It does, I just measured its digital output, not the analogue output you are referring to. I measured only the digital output because it´s 20 bit capable and with it I can have a look at the performance of the ATRAC chip not influenced by anything, not even the D/A converter. I never measured its analogue specs so I don´t know how it actually performs when connected via a pair of RCA cables to an amplifier.

But Kenwood DID lie about their specs nonetheless: they advertised that machine as having ATRAC 4.5 - this isn´t true since it has the ATRAC 4.0 IC.

[sfbp]

I didn't realise that the specs quoted on all those manuals are for analogue output only.

I wonder what the corresponding numbers are for a high end Sony deck? In turn this raises the interesting comparison of what the specs of some relatively lowly decks are like too. It could be that all the differentiation between medium and "top" models is in the D->A.

[MDietrich]

I didn't realise that the specs quoted on all those manuals are for analogue output only.

I wonder what the corresponding numbers are for a high end Sony deck? In turn this raises the interesting comparison of what the specs of some relatively lowly decks are like too. It could be that all the differentiation between medium and "top" models is in the D->A.

The Drive plays a minor role, even the power supply is not so important as manufacturers would like us to believe. The D/A converter is important too - but the most important parts is how the output is designed, I often call it the "D/A converters surroundings". Even a good converter will still sound bad and perform well below its intended specs if it´s used in a poorly engineered deck. From my experience with portable CD players I can safely say that Sony knew what they were doing, they managed to get the best performance out of these chips.

If you´d like to know how a Kenwood DP-5090 (CD player) performs through its analogue output:

[sfbp]

Right. My point being - that I would like to know if the assumption I have made over the years is correct - namely that optical out into a really decent receiver (definitions welcome!) obviates the necessity to pay for high-class DACs on the MD or CD itself.