Blast from the Past: MiniDisc, Wide Bit Stream and 20 Bit

I cannot really tell you, dear reader, why I´m so interested in ancient digital technology. I suspect several reasons but none of them seems clear enough for me. But I know that it seems to be interesting enough for others too - otherwise I couldn´t explain the 3000 monthly pageviews I still find surprising given those geeky topics I usually write about. Today I will not only write about a nerdy subject but also about an example of now ancient technology that quickly became technically obsolete: the MiniDisc. Some months ago I reviewed several portable CD players I had acquired; in that same article I mentionend in passing my first MiniDisc recorder bought in 1996, the Sony MZ-R 30. I also published several measurments I made with this unit and talked about some of the technical features enabling the MiniDisc to function. Ever since that article I had the nagging feeling that I needed to elaborate a bit more on the technical aspects of that system as well as writing about its sound in detail. Well, here it goes.

MiniDisc logotype (copyright: Sony)

The MiniDisc was introduced to the market in 1992, at a time when sales CDs reached an alltime high and the Cassette Tape approached its final evolution with the introduction of Dolby S. By then it already was apparent that the Tape was going to be replaced by CD technology, just the same as Vinyl was. Additionally, Sony and Philips had already developed and standardized the CD-R format in 1989. Back then however the technology needed for CD-R (lasers and media) was alarmingly expensive & still in its infancy so both companies developed something else supposed to be equally capable of digital recording but much less costly. Philips decided on the ill-fated DCC format while Sony decided to use something more cutting edge: MO-discs. They also determined the new format to be much smaller than anything else released before; in order to achieve that they had to use a lossy compression scheme. The result was an MO-disc shrinked to one fifth of its former size combined with a newly developed lossy compression called ATRAC, all of it encapsulated inside a nifty package looking like a tiny floppy disc. This new format appropriately named MiniDisc was - just like DCC - released in 1992 in form of the portable recorder MZ-1. From the minute they presented it I was fascinated by it because it offered some traits completely new to the audio world. Beside being able to record something digitally the MiniDisc was highly portable (remember: we are talking about a time when flash memory was still in its infancy and had yet to be released). But it was the possibility to edit its content to your liking that catapulted the system into the limelight: a user was able to move around or to erase a particular track or several tracks, one could also divide or combine these tracks. In short the perfect personal "Best-of" was now possible - all in flawless digital quality with then unknown portability. Or so Sony thought.

Sony MZ-R 30: have a look at the "Erase" and "Track Mark" buttons - a first back then

Since Philips was going to unleash its DCC system in 1992 Sony had to follow suit in order not to loose marketshare. The engineers of the first MD recorder however knew that they would need at least another year to perfect the compression scheme ATRAC. Have you ever heard the first mp3-encoder from the Fraunhofer Institute? I´m old enough to remember that I did; it sounded just awful. I encoded some track from an Enya album with 128 kBit/s and after decoding it back to .wav I noticed a strange pumping effect and distortions like flanging and pre-echos. Clearly, mp3 wasn´t ready to be used - and the same happened three years prior when the MZ-1 was released. Early tests noticed some strange artifacts sounding like crackling fire on top of sounds in combination with a generally metallic and dull sound; the first version of ATRAC just wasn´t ready for public release. The biggest leap in quality was supposedly achieved with ATRAC 2 one year later: much less metallic, frequency cutoff extended to 18 kHz (before: 15 kHz) and less audible crackling noise. ATRAC 3 from 1995 came close to DAT in a DBT, the crackling noise had almost disappeared. But only ATRAC 3.5, released first in August 1995 with the home component MDS-JA 3 ES would be virtually indistinguishable from CD without metallic sound, noise or anything else. This story serves to illuminate the course of technical improvement being quite visible to the general public. Especially people in Europe were very critical of the new system: the MZ-1 was very expensive, MiniDiscs were equally expensive and all of it sounded just awful. Additionally Sony made an incredibly stupid marketing error: Instead of concentrating on the systems' recording ability they advertised it with pre-recorded MiniDiscs, leading many people to believe that the MD was the CDs successor. Back then people hadn´t yet accepted lossy quality and so they stayed with Tapes a bit longer. In Japan however the MiniDisc was successful from Day One.

Sony MZ-R 30, using the Wide Bit Stream capable ATRAC 4

But all of that changed with the MDS-JA 3 ES. The major reason for improved quality was the decision to switch to quasi-floating point operation within the ATRAC encoder/decoder circuit. Sadly it is an almost publicly unknown fact that virtually every lossy compression scheme (mp3, AAC, OGG) internally works with floating point arithmetic. Integer processing isn´t suited that well for audio since it only can support a limited range of values whereas floating point can represent an almost unlimited amout. The first three ATRAC IC designs processed by using integer values only, limiting their range. When Sony got rid of this restriction ATRAC was ready to work with improved quality, subsequently becoming able of capturing high resolution material. Using their patented "Block Floating Operation" the MiniDisc now was ready to process and store information with higher resolution than CDs 16 Bit. And instead of reducing the bit depth to 16 Bit again during en/decoding Sony just used 20 bit capable A/D-D/A converters in order to make sure that the improved processing depth would be preserved. Meaning: the MDS-JA 3 ES was the first truly 20 bit capable consumer recording device. In 1995 this was a small revolution - not one recorder had been capable of delivering a resolution that high up until that point. Sony therefore took the wise step by advertising it as such while making sure that every internal processing step matched this 20 bit capability, calling the entire process "Wide Bit Stream". On home consumer devices a resolution this high makes perfect sense, it´s an entirely different situation with portable recorders however. Even if a recorder like my MZ-R 30 would work within this bit depth it would be pointless; its combined A/D-D/A converter Asahi Kasei 4515 is a true 16 Bit converter, rendering the internal processing power useless as a result. Likewise, digital 20 Bit sources weren´t existing back then so this impressive processing precision effectively only made sure that CDs were encoded without flaw.

But since the day I first read about it I have been interested in finding out if Sony spoke the truth. Could a lossy device like the MD be capable of delivering higher-than-CD resolution? All those years ago I couldn´t do revealing tests myself only because I lacked the equipment for it. But hey, we now have 2012 and I own the Creative Sound Blaster X-Fi HD USB! As you know it features optical in/outputs delivering true, bit matched 24 Bit signals. My boyfriend also owns a Kenwood DM-5090 (1997) which I suspected to be Wide Bit Stream capable. BTW, despite being advertised featuring an ATRAC 4.5 IC the Kenwood only uses the same ATRAC 4.0 IC from my MZ-R 30. For measuring pure ATRAC performance I devised a  test routine that would protect the digital signal integrity at every step during my procedure without any analogue intersteps. I created an RMAA generated test signal with 24/44.1 and did the following:

SB X-Fi HD ---> Sony MZ-R 30 (recording) ---> Kenwood DM-5090 (playback) ---> SB X-Fi HD

Recording was done digitally using the MZ-R 30

Playback was done digitally with the ATRAC 4.0 equipped Kenwood DM-5090

The results were surprising to say the least. My old MZ-R 30 turned out to be a true Wide Bit Stream capable recorder - only when using digital connections of course. Just imagine you now would find out that a recorder you´ve known for 16 years has been capable of capturing high resolution all the time. For Christ's sake, this thing is from 1996, a time when not even recording studios were using 20 Bit regularly! The Kenwood DM-5090 was equally surprising since its digital output delivers a true 20 Bit signal. A) for a consumer device it would make much more sense to transmit with 16 Bits only and B) my resulting files were actually 20 Bits inside a 24 Bit .wav file (as indicated by the Bit-meter in WaveLab). Look at the results:

Entirely digitally transmitted 16 Bit test signal yields 16 Bit performance using ATRAC

A 24 Bit test signal yields 20 Bit performance thanks to WideBitStream

For comparison: mp3 320 kBit/s CBR (Lame 3.98.4) with 20 Bit output

Sony told the truth indeed: even a small portable MD recorder is capable of recording true 20 Bit quality (Dynamic Range would need to be roughly 10 dB better though). The 16 Bit signal results in 16 Bit quality while the 24 Bit signal yields 20 Bit quality. It would be interesting to measure the output of an ATRAC 4.5 equipped device since that particular ATRAC version was the first to use full 24 Bit processing. Furthermore you now can see how mp3 behaves when it´s properly decoded, allowing it to deliver the full resolution of its internal 32 Bit floating point data (for fairness decreased to 20 Bit in the example above). The mp3 measurment also serves as an example how much lossy codecs have improved during the last 16 years. Granted, results are a bit unfair since ATRAC uses 292 kBit/s whereas the mp3 test signal above was encoded with 320 kBit/s. The most important measurment for all three examples is Total Harmonic Distortion plus Noise (THD + Noise), ATRAC measures 8 dB worse than mp3 which might lead to more audible compression artifacts. But considering its age, its limited processing power and implementation ATRAC fares impressively well. Of course, with every lossy compression scheme only the output with real music counts so measurments might not reveal any sonic shortcomings. For that I not only recorded test signals; I also copied several music examples the same way as described above to find out if ATRAC sounds different to the originals. To determine if there was an audible change was indeed quite difficult, proof to how well Sony designed the whole process. It could very well be a placebo effect but I was under the impression that ATRAC widens & deepens the stage impression very slightly leaving tiny "holes" and a not so stable stage. It also seemed to sound either too harsh or too mellow depending on the material - but keep in mind that the perceived effects were so slight that I´m not sure I´ve even heard them. Impressive, don´t you think?

Sony MZ-R 30

But how does the MZ-R 30 sound? I´ve already talked about this before - but I didn´t rate its sonic quality with my new rating system. The sound of the MZ-R 30 is fairly balanced, blowing up upper bass while missing high frequency detail. Despite this it displays slight loudness-switch characteristics, emphasizing bass and treble frequencies around 10 kHz, efffectively draining sonic colour. Dynamics seem to be held back with the result that the MZ-R 30 always sounds "nice"; bass is soft and misses punch, transients in general are too soft. Staging is fragmented yet flatter and convoluted, guessing size and position of instruments is becoming difficult for the listener. It´s like hearing a fuzzy bubble without much depth and width. What suffers most however is resolution; details are rendered far to casual, more often than not high frequency detail turns into simple noise. High frequency intelligibility really isn´t very well rendered on this device, yielding a voluptuous and too warm sound. Don´t get me wrong, it sounds moderately well, definitely better than 40% of my portable players. Without colouring the sound too much it presents music very pleasant, you can therefore listen with it for extended periods without suffering from listening fatigue. Its headphone output on the other hand - although powerful enough - sucks big time. Using it one looses much crispness, it sounds surprisingly dull.

Sonic Balance:

Dynamics:

Resolution:

Stage / Ambiance:

Character:

A personal Note

Of course it´s pointless to use such an ancient device in present times. Recent portable players can be filled with music in a matter of seconds, offer theoretically improved sound quality (using lossless FLAC and improved technology) and are much smaller in size while offering reasonable running times. With musical gadgets convenience always is key while quality plays a secondary role. Therefore technological obsolescence plays a major role in the death of the MiniDisc. 

But there are other reasons as well... up above I´ve talked about CD-R - since they were so expensive Sony estimated it would take a long time for them to become affordable. They were wrong: recordable CDs became cheaper than MDs in 2000/2001, rendering the MiniDisc an inconvenient and slow recording device with a compromising quality approach. The mighty giant Sony reacted with altering the MD format by introducing an advanced version of ATRAC called ATRAC3 (not to be confused with ATRAC 3) which allowed longer recording times by lowering the datarate (64 kBit/s & 132 kBit/s). Needless to say that such recordings were incompatible with older MD devices. 

Around the same time a second problem arose: portable mp3 players. Sony tried to counter these developments with another new feature released in 2002 called NetMD where you could - using your PC - upload your music to a recorder equipped as such via a built-in USB link. Of course, you had to use the proprietary ATRAC compression scheme, meaning that you had to re-encode your collection of mp3-files, lowering the quality even further (lossy re-encoded to lossy). For all consumers it was as clear as day that this was highly inconvenient and extremely impractical - but Sony found nothing by it. Subsequently many consumers parted with Sony and the MiniDisc. 

Kenwood DM-5090 - an MD recorder from the systems' heydays - and not even from Sony

The last nail into the coffin of MiniDisc however was the release of the iPod in 2001 and its subsequent success. Again Sony completely misinterpreted unfolding developments and tried to revive the almost deceased MiniDisc corpse by improving the recording quality. They introduced the Hi-MD in 2004 - for the first time in its life the MiniDisc was able to record and playback music in true lossless 16/44.1 quality, all of that combined with NetMD "comfort". Yes, they dropped the Wide Bit Stream feature entirely. It´s ironic: to infuse the system with new life they not only sacrificed something that made the MiniDisc unique (admittedly: many people didn´t care) but also compromised backwards compatibility. Sony subsequently lost its "coolness", the MiniDisc was just one of many decisions made in the first years of the new millenium that stank of stupidity. The once shining company that produced legendary components now is just a mere shadow of its former self, making more profit with finances (!). Remember: Sony is at heart a manufacturer of electronics and not a bank. Today Apple is hip while Samsung is market leader, both traits were personified by one company just ten years ago: Sony.

Sony may die a slow death - but thankfully their components are still around and obviously built to last for quite some time. I for one have decided to go back to the MiniDisc system for now, even though production has ceased in 2011 and I myself abandoned it in 2001. Why am I so stupid and unreasonable? I don´t really know... but the first time I touched the Sony MZ-R 30 I knew that I was in love. This never happened when I received my Sansa Clip+, it was just another device playing music. Furthermore I never trusted mp3 - without a logical reason really. By now lossy codecs have reached a mindboggling quality, with higher data rates they in fact are transparent. Still, to me mp3 always sounded a bit dull and compact. I know, I know... completely stupid and very likely a placebo. But I can´t help myself, I always perceived the MiniDisc to sound better. It also looks and feels very nice, it has a haptic mp3 cannot reach since it´s immaterial. Some weeks ago I read an essay in the German news magazine Der Spiegel called "You cannot love files". This article described how soulless downloaded music appears to many customers´and it argued that today you can buy music in a second and have it on your portable player the next. But you cannot hold it in your hand (like a CD , MD or even Vinyl), leading to a feeling of being disconnected from it. You don´t have to occupy yourself with it anymore, it´s just data confined within impersonal files. I´ve always wondered why I "remaster" every CD I buy (which are many), maybe it´s because I want to "connect" with it before it ends up in pristine quality on my HDD where it´ll only be a collection of files. My recent interest in vintage portable players or the MiniDisc forces me to do the same, I have to bother myself with the music, I have to spend time with it. In any case I have not understood the reasons for this yet, I´m just starting. Maybe it´s much simpler and I´m starting to get old. Equally possible but you know what? I don´t care because I want to enjoy music in very good sound - and the MiniDisc allows me to do that despite (or because?) its shortcomings.

More vintage portable Players compared!

EDIT: I´ll advise you to read the first paragraphs of another article about vintage portables. There you find the reasons for the strange sonic behaviour of the D-NE 1.

You know, I really have a lot of fun doing these little comparisons between vintage portable CD players. My first and my second articles were just a start it seems as I´m unable to stop buying these portables. I also enjoy listening to them one at a time, most of them do indeed have a better sound quality - even though they are quite bulky - than my lovely Sansa Clip+. Despite my initial dislike I´ve used the (now repaired) Sony D-465 quite often during recent weeks because it performs so well when I use it in combination with my FIIO E6 and my Sennheiser HD-448 (seems to be a classic synergy effect). The piercing treble and the slightly recessed mids form a balanced sonic partnership with the slightly recessed treble and exaggerated lower mids of the HD-448. I´ve also used the Sony D-20 a lot, it is a breathtakingly beautiful sounding machine. I´ve come to love its very stable and precisely described stage impression. In general it seems that I´m rather fond of players who tend to colour or tweak the sound a bit into a certain direction, a direction that isn´t faithful to the original sound of the recordings. It appears that I´m also fond of euphonic distortions and even though I consciously know that I´m listening to a lie my heart on the other hand simply won´t stop telling me that listening to these players feels so good. I´ve avoided the Technics SL-VP 50 during the last weeks for example, it sounds so damn close to the originals and my ASUS Xonar Essence ST that it doesn´t present anything new to me. Then I´ve listened to my old Technics SL-XP 300 a lot - and I can only say that I hate it! It seems to do everything wrong: while it shows a wide stage this stage tends to be flat with a lot of added ambience (distortions?), mids seem to be underrepresented. Well captured organ recordings are easily able to reveal the limits of this player in an excruciating fashion. Yes, this player lies too - but not very good. The Sony D-EJ 915 from my last review is something else too: while it fared really good I have been avoiding it. Not because it sucks, no, it´s only that it´s boring in its perfection (combined with that fuzzy stage that starts to disturb me) and therefore again nothing new. Let´s face it: while I strive to hear sonic perfection with vintage portable CD players most of the time I find myself actually preferring the opposite. I´ve always prided myself in being able not to fall for the typical audiophile preferences (an electronic device that "interprets" music in an engaging fashion) so I´m a bit ashamed of myself that I have a weak spot for euphonic sound. Naturally a machine is unable to intepret the music but many people seem to think that they do nonetheless. Both preferred players I mentionend are for instance unable to "interpret" pop or rock music - even more valid for the D-20 - but they are gorgeous with classical or orchestral filmmusic. Is this psychoacoustics? Probably.

One of my tools for casual listening: the FIIO E6

The other tool: Sennheiser HD-448

But today I´d like to talk about the Sony D-NE1 and the Technics SL-XP 490, my most recent additions. The Technics was released in 1995 and is one of the few players by Technics with an ESP. In Japan and the U.S. it was released with an optical output, the European version does not carry this handy advantage enabling digital recordings. When I take it apart I can see an empty space for it on the mainboard, the housing seems to be prepared for it too since it shows a cutout. I would have loved to record the digital output of the famous Technics portable CD drive with my MD-recorder Sony MZ-R 30 (btw, this will run out of competition for this review). Well, the Technics was quite cheap and in decent condition (the lid is scratched a bit) and it functions well, it has one of the fastest drives I´ve ever seen from a CD player. The Sony is a fairly modern and new player, it is in fact my most modern portable. Sony released it in 2002 to the market and it´s - apart from the lid - similar to the Sony D-NE9. I bought it in used condition from some idiot at Amazon.de (I could tell some stories you wouldn´t believe but I´ve decided to spare you this gruesome experience) for too much money, when new this player cost 250,- Euros. My player came with a cable remote control, an attachable compartment for two AA-batteries, a battery charging stand, software, a carrying pouch and headphones. The latter went to the garbage bin immediately but I was very happy to have the other additions since I can use the external battery compartment and the remote with the Sony D-EJ 915 too (only with that remote the EJ 915 is able to show CD-Text). The D-NE1 doesn´t have its own display because it has been attached to the remote instead - quite stupid if you ask me, I´d much prefer a display on the player itself but on the other hand it keeps the player small. The D-NE1 is also the only one of my players capable of playing mp3-CDs and just like the D-465 and the D-EJ 915 it boasts an optical output.

Technics SL-XP 490: not very beautiful if you ask me

Sony D-NE1: much better but abused

As you can see on the picture above the Sony was abused by its former owner. The lid appears to be severely scratched, even the battery charger stand shows some scratches. You know, this is something that I´ve never understood: why can´t people treat electronic devices with respect? Don´t these people prefer those things to work for at least 20 years or so? Don´t they prefer them to look good and proper for a very long time? Even if they are only portables? I wouldn´t want to be hurt, not even if I´d be a gadget like these. Despite the surface blemishes it worked very well from the start - a wonder really because when I took it apart to clean the flat ribbon cable and to lubricate the drive I noticed some liquid inside the compartment for the recheargable gumstick batteries, there even was some of it on the mainboard. Maybe some batteries lost their chemicals or the idiot who formerly owned the player poured something into it, I don´t know. Needless to say that I thoroughly cleaned it from the inside, including the mainboard which otherwise looked pristine. Anyway, now that I´ve cleaned it it looks and feels much better. I still have to wash the carrying pouch though; who knows how dirty the hands formerly touching it were? Remark: I just paused this article to do just that: handwash the pouch with warm water and washing detergent. The clear water turned into a brownish yellow! Yikes!

Details Sony D-NE1

The transparent, acrylic lid is made out of plastic but has a slap of round metal attached to its upper side. Despite its tiny size the player is suprisingly heavy and feels sturdy, the used plastic doesn´t feel cheap or fragile. I´ve also scratched my head before owning it myself whenever I saw some photo of the player because the photos seemed to show me a rather bulky player when in the accompanying text people constantly were talking about its small size. Well, I now appear to do the same because this player is really tiny. It´s even thinner then my Sony D-EJ 915 and only a bit thicker then a Jewel Case.

The outputs are a hint showing the actual size...

... but this comparison to a CD ("The Core") should make it clear immediately

Just for comparison I´ll also include a third portable: the Sony MZ-R 30. I don´t have a particular reason to do this, it´s just that I always was in love with the MD format the minute it was unleashed. The results of this recorder won´t turn up in my 'sonic pictures' but I´ll include the measurments since they highlight that a unit using lossy compression cannot be measured with the usual signals. The MD format was released by Sony in 1992 with the Sony MZ-1, a really horrible sounding and bulky portable recorder. It´s telling that the company used a portable recorder to present a new technology; the MD format is perfectly prepared for portable use. Housed inside a plastic case the little MO-disc is extremely durable, sturdy and able to withstand extreme stress (there have been cases where MDs have been crushed by a car - the MD case was destroyed but the disc itself was still working perfectly). Before the advent of Hi-MD lossy compression was necessary to reach the same runtime as the CD, the compression scheme used for that task is called ATRAC which is similar to mp3 but uses a much higher data rate.

Sony MZ-R 30

ATRAC (version 1.0) was used on the Sony MZ-1 and sounded like crap, clearly audible artifacts were introduced. Furthermore only a few companies offered pre-recorded MiniDiscs and so the new medium wasn´t very successful despite offering (a first back then!) delicious editing possibilities not unlike those possible on a PC. Only with the release of ATRAC 3.5 in 1995 it finally reached transparent audio quality mainly because of 32 Bit floating point internal processing, later MD recorders were even able to record and output true 24 Bit quality because of that. The ATRAC 4.0 chip used in my MZ-R 30 is nothing more than ATRAC 3.5 where three chips have been combined into only one. Since the MZ-R 30 was the first portable MD recorder to offer very good quality it was very successfull (even in worldwide markets) so you can still find a used one in decent shape on eBay. It was my first MD recorder and I´ve always cherished it, I´ve spent many happy hours with it. The built quality is perfect, the housing is made out of metal and it generally is a sturdy little thing. Why am I not including the results in my sound pictures? Because the sound quality is not only good (especially for a recorder using an early lossy compression codec) and balanced but a tad boring and uninteresting. There are some additional obstacles: sound quality differs depending on the material. Sometimes it´s full of details and sometimes it´s more mellow. The stage response however suffers the most with this unit for performers seem to change positions and size, it seems as if the stage is somehow fragmented. But it has a very impressive recording quality nonetheless for its age and size... which of course isn´t needed anymore nowadays since MD has become obsolete. HDD recorders offer better quality and even better editing possibilities while mp3 players took the portable playback market by storm with even smaller size and improved convenience.

Sony MZ-R 30 with opened lid

Measurments

As always, my "Measurments" are not really measurments in the strictest sense because I don´t own actual measuring equipment. So - as I did before - I used my E-MU 0202 USB for RMAA test signals and jitter tests (with the same cables and under the same conditions). Additionally the players were not powered by their batteries but by their AC power supply - just like with all my other tests. I recorded their outputs with 24/192 and downsampled the recorded results to 16/44.1 (non-dithered) later. Before downsampling however I amplified the amplitude of those signals to 0 dBFS only because RMAA doesn´t have an idea about absolute levels and also because portable players do not use the quasi-standard output voltage of 2 V on their line-outs. While this amplification distorts the noise responses somewhat (I could very well end up measuring my E-MU instead) it nevertheless represents a fair comparison because every result is level matched. The music examples were treated the same way - except that I amplified the calculated amplitude minus 1 dB difference. I do this to counter distorted peaks caused by inter sample clippings (many CD players react to them by putting out distorted or louder peaks) which in turn could pose problems for the resampling process. Needless to say that the digital originals I´d be comparing the results to have exactly the same amplitude, the same samplerate and bit depth (24/96). In case of the Sony MZ-R 30 my test CD and the music examples were recorded digitally onto MD with the D-EJ 915 doing the playback.

Sony D-NE1 - amplitude amplification to 0 dBFS: 8.6 dB

Technics SL-XP 490 - amplitude amplification to 0 dBFS: 10.5 dB

Sony MZ-R 30 - amplitude amplification to 0 dBFS: 8.5 dB

Sony D-NE1: perfect frequency response

Technics SL-XP 490: this deviation at higher frequencies should be audible

Sony MZ-R 30: lossy compression is the reason here

Jitter Sony D-NE1 - impressive

Jitter Technics SL-XP 490: equally impressive

Jitter Sony MZ-R 30: quantization noise (-> lossy compression) obscures the sine

All devices are measuring very well even though I don´t know how much the Sony MZ-R 30 jitters. But since jitter isn´t that much of a problem with more modern digital gadgets anyway I think that it can be ignored, I suspect that the Sony does its job well enough. What you cannot see however is how well the two Sonys reject imaging products, their stopband rejection works perfectly (keep in mind that the MZ-R 30 only uses a A/D-D/A converter combined into one chip!). The Technics however shows poor aliasing rejection: visible imaging products from 22.5 kHz onwards with clearly visible aliasing products reaching into the passband as low as roughly 14 kHz. It could be interesting for future measurments to look for impulse responses, the high frequency drop off of the Technics in combination with the imaging artifacts hint at a spline-like digital filter - or at a badly designed filter. The perfect 20 kHz-cutoff of the Sony D-NE1 is probably caused by a resampler; it´s perfectly possible that it´s using one since it has to be able to playback 48 kHz mp3- and ATRAC files so a converter that´s sampling at 48 kHz is most likely used (stupid me, I forgot to check 48 kHz playback with lossy files and I also forgot to look for the absence of two quartzes on the mainboard to confirm my assumptions). The sharp 18 kHz cutoff of the MD recorder shows that the lossy compressor ATRAC 4.0 cannot handle high frequencies when exposed to multi-tone test signals (and possibly music displaying a similar full frequency response), it simply erases them just like any other lossy codec would do (mp3 for example does this at roughly 16 kHz depending on the material and data rate).

Sony D-NE1 lid opened

Technics SL-XP 490 lid opened

Listening Tests

The Technics SL-XP 490 sounded wide and a bit distant. Sadly, the stage impression wasn´t very stable, performers seemed to move a bit from one second to the other. The stage also seemed to be lit a bit "dark", I don´t know any other words to describe it. Details audible in the digital originals weren´t always present but despite the measured drop-off in treble it didn´t sound too blanketed, it surprisingly sounded a bit too crisp. The sound is not really bad but not too impressive either, it doesn´t show the amount of recessed mids of the Technics SL-XP 300 and it also doesn´t show its punchy dynamics. Timing is well enough to not be bothersome. But: bass frequencies are too soft, they sound like a thick cushion. The decay (fade out of certain notes) disappears without much control. The Sony D-NE1 was the complete opposite with almost all characteristics: stage appeared a tiny bit too small and more holographic compared to the originals (which is a strange feeling if you´re not used to something like this). Apart from that it seemed to "jitter" a bit (performers seemed to wobble around slightly). Frequency response was balanced although I had the feeling that treble was too brilliant, resulting in a slightly nervous sound. But hooray!, this was the first player that got the bass right: it was strong enough, punchy when needed and very tight - not the soft mess the Technics presented. I´ve often read comments about the more recent portable Sony CD players that their bass supposedly is too overbearing - I doubt that this is true since the D-NE1 is the only one that closely matches the characteristic of the originals, it was a joy listening to "Swim" from Madonna's "Ray of Light". Still, there´s something strange going on: when I listened to the output with my FIIO E6 the stage was even smaller and more holographic, furthermore the too crisp high frequencies were gone. The latter were only apparent when the output was recorded with my E-MU 0202 and now I´m left wondering if the output of the Sony reacts differently to different inputs. As you may know, the input of a device presents a passive load (the resistance is measured in Ohm) to the (active) output so maybe the input of the E-MU presents a smaller (or bigger?) load (it must have an amplifier because the recording level can be increased - but does that change the resistance?), I really don´t know. Whatever the reason is, I prefer the more compact sound displayed with the FIIO E6 since it´s more balanced and also because the extremely controlled holographic staging is so appealing.

My perceived frequency response of the two players (via my E-MU 0202)

Perceived staging of the Sony D-NE 1 - exaggerated of course

Perceived staging of the Technics SL-XP 490 - exaggerated as well

Conclusions

Since I have mostly been listening to music with a player I formerly derided as being awful during my earlier tests (the Sony D-465) I´ll now be very careful to pronounce a winner. It could very well happen that I find myself listening to the Technics SL-XP 490 in a few weeks or that I´ll be listening to the Sony D-NE1 instead. The latter is of course the more portable player so it probably will receive more time to show what it´s worth. In any case, I have to expose myself constantly and unconsciously to all my players to find out how they sound. The comparably short reviews I´ve been doing were executed with the utmost biggest care of course but us humans tend to react differently when we listen to music while doing something else, like reading for example. This uncounscious listening was responsible for favoring the Sony D-465 and the D-20 over all the others, even though they colour the sound or are introducing some sonic errors. Therefore I reserve a final statement for some furture article where I will come back to all my portable CD players again - until then enjoy some more pictures.

Technics SL-XP 490

Sony D-NE1 from behind on its battery charging stand

Sony D-NE1 on its stand again - quite nice I think

Sony MZ-R 30 detail

Sony MZ-R 30 detail