Category: Portable CD Players

THE GOOD, THE BAD AND THE UGLY. CD PRESSING QUALITY

January 22, 2018

When talking about CD quality we usually mean original files used, be it the original master tape (RCA Living Stereo, Mercury), or AAD vs. DDD recordings, and/or mastering engineer: Steven Hoffman, Manfred Eicher, Doug Sax, “Prof” K.O.Johnson, etc, etc…   Other-times companies make a name for themselves by paying special attention to CD mastering chain: Esoteric SACDs, JVC-XRCDs… Mobile Fidelity gold CDs became highly collectible because of the mastering quality but also because of the layer of Gold instead of Aluminum used during CD production. Wadia 781i revealed yet another step in CD production chain where things can go wrong: final CD pressing. This step takes place at some anonymous plants churning out CDs for the major and audiophile labels.

Complains from Wadia users about “unplayable” CDs are all over the net, and my Wadia 781i is no exception. It refuses to play badly pressed CDs. It plays CDRW and scratch-test CD (CD with 1mm black scratch across its diameter) without any problems, thus indicating that laser mechanism and digital circuitry work OK.  Badly eccentric CDs (e.g. Stereophile Test CD3) or warped CDs (e.g. Schoenberg/Simon Rattle, EMI 4 57815 2) do not even get recognized as CDs by Wadia: “No Disc” message pops up.

Considering the amount of efforts hi-end companies and audiophiles put into isolating CD players from external vibrations, it makes sense not to use CDs which make the player vibrate from the inside. As explained by Steve Huntley (see square-2.com: wadia-781i-taming-the-beast”), Wadia designers chose not to compromise overall Wadia sound quality for the sake of 0.01% of badly pressed CDs.  In my opinion, in actuality this was an unintentional glitch, it will be discussed later. Right now I want to present some data proving that Badly Pressed CDs do exist, and that it is quite possible to fix them.

CDs not playable by Wadia are easy to detect by playing them on a portable CD player while holding Discman in you hand. With bad CDs Discman vibrates like an unbalanced centrifuge! These last few months I was trying to find a way to make this test a bit more “objective”. Help came from the drone/quad-copter aficionado: Bogdan R. of tankydrone.com.  He loaned me a few flight controllers, once attached to CD laser mechanism, chip accelerometer and gyroscope detect the level of vibration during CD play. Accelerometer in quad-copters is just an afterthought, but gyroscope is sensitive enough to provide meaningful and reproducible results on Discman vibration, or rather changes in Discman position when it is allowed to wobble.

Here is Tanky flight controller chip attached to CD laser mechanism:

Three rubber grommets let the mechanism “float” inside the shell:

 Three more grommets let the Discman wobble over the desk. Any vibration generated by spinning CD is detected by the gyroscope:

CD platter motor is connected to 1.5V regulated dc, CleanFlight software picks up the signal off the Gyroscope and Accelerometer. Unlike all other Bad CDs in my collection, this CD is warped (exactly like a warped LP), not unbalanced. It needs Furutech LP Flattener, no amount of balancing could make this warped CD playable by Wadia:

Here is a salvageable CD, originally rejected by Wadia:

Vibration graph before any treatment, horizontal vibrations from a spinning CD push the player up to 20 deg/sec:

CD edge is trimmed by AudioDesk CD lathe:

Graph after edge trimming, horizontal vibrations lowered from 20 to 15 deg/sec:

With slight modifications Magnetic-Levitation propeller balancer (once again, help arrived from TankyDrone!) can be used to check if CD is perfectly balanced. Pieces of aluminum foil can be used to balance CD:

Graph after CD balancing:

Practically no vibration, max 5 deg/sec!

Here is the end result of edge trimming and balancing:

The only “off the shelf” CD with such low vibration specs is an overpriced Esoteric SACD:

A few more CDs originally unplayable by Wadia:

Vibration Graphs show the effects of CD edge trimming by Audio Desk CD Lathe followed by CD balancing using propeller balancer.

For the next CD original vibration reached 28 deg/sec! Edge trimming did not reduce vibration indicating that CD was perfectly circular and that there was some other reason why CD was badly unbalanced. Once Balanced, vibration dropped to 4 deg/sec:

Here, once again, CD trimming did not reduce vibration, only CD balancing did! Please notice the dramatic decrease in Z-axis (vertical) vibration:

Below is the effect of CD trimming and balancing on CD issued by my favorite audiophile company. Once again, the most dramatic improvement is seen at Z-axis:

TO BE CONTINUED…

Black Gate capacitors and “snake oil” in home audio

January 14, 2017

Having nothing better to think about, I was trying to remember when and why did I fell in love with Black Gate capacitors. I must have learned about their existence from reading audio-porn at DIY or some audiophile site. Black Gate caps were the top-shelf audio-grade electrolytics produced by Rubycon. Quite expensive while in production, outrageously priced nowadays, the name should not be mentioned at any respectable DIY forum. The consensus seems to be that the specs of modern-day electrolytics far exceed those of Black Gate caps. This may be so, but not quite conclusive for me because specs alone do not tell the whole story. The specs of any $50 CD player are the same as those of $100k+ dCS stack and always better than the specs of Continuum Caliburn turntable, unless you actually listen you never know.

Living through the decade of “perfect sound forever”, then witnessing the births and stillbirths of SACD, DVD-A and hi-rez downloads, I tend to disregard other folks opinions about audio reproduction. Our present-day consensus is that people do not hear the difference between MP3 and CD, that all CD players (or amplifiers, turntables, interconnects, etc) sound the same, etc, etc,… Once in a while I use my own ears to “see” what those other people are talking about. Once the legend of Black Gate electrolytics piqued my interest, I shelled a few bucks and installed Black Gate caps where I had no choice but to hear (or not!) the difference: into one of my D-90 Discmans. I really liked the end result, it was the easiest and the cheapest A/B test imaginable. One D-90 Discman with all-Rubycon caps, another one with Black Gate caps, synchronously playing CD-R copies of Mendelssohn Violin Concerto convinced me that I should get Black Gates for ALL my Discmans.

Falling for the “snake oil” of Black Gate capacitors reminded me of a comment I posted some time ago for the following CNBC blurb:

Hi-fi music streaming: People can’t tell it when they hear it

Now that my comment is either deleted or forever buried under later comments, here are my thoughts on the subject:

Last year it was David Pogue of Yahoo! who became an internet darling after sharing his blind test of Pono player:

The Pogue Review: PonoPlayer

His video “proved once and for all” that Pono is full of bull. It was good for David Pogue, it was even better for Pono: a lot of new people (myself included) had learned about Pono existence.

Here we have another such test. We learn that the discussion of the “master tape” vs. “perfect sound forever” had been downgraded to the question of CD vs. compressed MP3 format. SACDs, DVD-A, Hi-Rez (and, of course, ana-phyles with their analog LPs and tapes) got thrown away like stupid misfits and discarded formats they are. As a professional scientist (15 years in the Academy plus another 15 in medical research) I want to share my thoughts on the subject.

Whatever the intentions of such tests, “dumbing-down the masses” to justify feeding them crap, or blind tests for the sake of “finding the truth” conducted over the years by Stereophile magazine, they all miss one important factor: you can NOT average such results! Lets imagine for a second that the problem of MP3 vs. 16/44.1 does exist…

There is a chance to test it the right way, the way it was done by Mother Nature. Conduct a blind, double-blind, ABX, or whatever test you want. Then give a callback to those few who “guessed right/got lucky” on the test. Repeat the test. You may stop here and check if the perfect bell curve of Normal distribution of the initial test had been skewed. Or you can repeat callbacks a few more times, until you select folks like Mike Fremer (analogplanet.com) who can hear the differences each and every time.

Just because most people, given a pen and a piece of paper, won’t be able to prove that E=mc2 (or even Pythagoras’ Theorem), does not mean that the laws of our Universe had been changed. Just because I never met anyone able to run 100m in less than 10sec does not “prove” it is not done every day by those few who can. All such double-blind/ABX/controlled studies will continue to show that on average the results are… average!

Individual people are not “average”. If I can hear the difference between LP pressed by MoFi and SACD/CD/HiRez but cannot hear the difference between MP3 and 24/192 file, it proves absolutely nothing. It may be construed that there is no difference, or that I do not know what to listen for, or that I do not care about the differences, or that I intentionally lie, or that my stereo is bad, or… whatever… However, any such conclusion is wrong, the result itself does not support any.

And then we add averaging. The very idea of averaging my results with those of professional musicians of, say, Berlin Philarmonic, looks extremely silly to me. It is like averaging scores of someone who does not know how to swim and drowns with the results of Michael Phelps: meaningless at the least and cruel to our intelligence always…

For as long as I live, loudspeaker designers are the only folks in audio whose sanity is not scrutinized by the public. “All turntables sound the same” and then we got LP12 Linn Sondek; “all amplifiers sound the same” and we got Naim NAP250; “all CD players sound the same” and we got Theta Digital, Wadia, CD12; “all interconnects/power cords sound the same” and we got Cardas, Nordost, Shunyata Research.

Let us do it again: “all digital files sound the same”. This time, however, anyone can prove us wrong. All that is needed is one CD (or lossless file) and iTunes (for those who know what I mean, you do NOT need Pono Revealer for this test). ANY file will do: Rachmaninov on Reference Recordings, or Kanye West, or Lady Gaga. As long as you, personally, recognize it as “music”, this should work.

Start iTunes, rip CD as Apple Lossless or import your 16/44.1 file.

Go to “preferences” and change “import settings” to MP3-custom-320kbps. Right-click on your lossless file and hit “create MP3 version”. Rename this new file by adding 320 to its name.

Go to “preferences” and change “import settings” to MP3-custom-160kbps. Right-click on your lossless file and hit “create MP3 version”. Rename this new file by adding 160 to its name.

Go to “preferences” and change “import settings” to MP3-custom-80kbps. Right-click on your lossless file and hit “create MP3 version”. Rename this new file by adding 080 to its name.

Go to “preferences” and change “import settings” to MP3-custom-40kbps. Right-click on your lossless file and hit “create MP3 version”. Rename this new file by adding 040 to its name.

Now, since some players (Pono for example) won’t even play 40kbps files, it is time to upsample all this newly created garbage to its original “perfect” status of 320kbps (or Apple Lossless, does not matter):

Go to “preferences” and change “import settings” to MP3-custom-320kbps (or to Apple Lossless). Right-click on 160, 80, and 40kbps MP3 files and hit “create MP3 version”. Do NOT rename files.

Listen to the files and try convincing yourself that 040 file sounds “almost as good” as the original file. Painful but doable. The pain you feel is the pain of those who can hear the difference between MP3 and CD, or CD and LP, or CD and 24/192.

Now, let us ask ourselves how many people in a double-blind or ABX test won’t be able to hear the difference between 40kbps and “perfect” 320kbps files? What about 080 file? 160? This is actually a valid question, without some kind of “negative control” any results are pretty much worthless. There will be quite a few folks in this group, on the “wrong side” of average: those with malfunctioning hearing aids, those who do not even listen, those who cannot comprehend or fill the questionnaire, those who get so immersed in music they forget about the test, those who get easily stressed, etc… Basically, all the same excuses we reserve for those who “claim” that they hear the difference between the average and hi-end music reproduction.

Why Discman?

December 6, 2016

Who would want a Discman in the age of iPhones?  No one walks out of the door without a cell phone, and earbuds is all you need to have “portable” music.

Better sound quality on the Go? Hi-Rez player  from Questyle, A&K, Pono, or even iPod with portable headphone amplifier usually cures this fit of audiophilia.

Some Discmans do sound better than iPods/iPhones, but all such players are the 1st and 2nd generation of Discmans and they are anything but portable.

So, who would want to invest time and money into decent Discman? Folks like me, the Lazy ones. I ripped a few hundred  CDs onto iTunes, now have just a few more thousand CDs left. My progress is slow, plus the flow of “incoming” CDs overwhelms my skills of ripping them.

Subscribing to Analog Planet and watching Mike Fremer posts on YouTube may give an impression that we live in the Golden Age of VINYL. Which is probably true, I am not old enough to comment. What I Do know is that now (AD 2017) we live through the Golden Age of Classical Music CD reissues! Any Amazon search for Beethoven, Brahms, Tchaikovsky + “box set” returns dozens of boxes with $1 per CD. Who can miss such deals? Only those who do not listen to classical music. Thankfully, this means practically everybody, that’s why the price for these boxes is so low!  Older audio-nuts already have most of these reissues, younger kids have yet to discover “classical music”: Lucky me!

Anyone who tries to rip classical music quickly realizes that re-tagging the files is a full time job. Tunes are listed according to pop-standards: Artist and Album.  Beatles+White Album, Nirvana+Nevermind, Beethoven+the 9th… Except that 9th under Karajan rips with the same tag as 9th under Kempe, or Abbado, or Bernstein. Anyone who has more than one reading of the masterpiece (and who does not?!) must re-tag it as No.9, No_9, #9,…

And this is where Discman is my best friend, I have one next to my “sweet spot” for the days when I am not allowed to listen to my hi-end stereo, another one on my bedside table, and two more in my lab and in the office.

This does not explain why I have a few dozen portable CD players… On the other hand, for those who have at least one “classic” Discman, no explanation is needed. Their beauty and build quality speak for themselves

Sony D-90 Discman

December 25, 2015

Sony D-90 is a very special Discman.  In 1990 this model was selected for an “upgrade” with 1-bit DAC,  Discman D-99 was born.  Once cheap 1-bit DACs found their way into CD players, it was a matter of months before the race for the “most affordable” player began. We all know how it ended. Opening the way to the slippery slope of ultra-affordable digital, D-90 symbolizes the end of “Classic” Discmans and the end of quality sound reproduction in portable devices. Audiophiles of the 80-ies thought that CD introduction was the beginning of the Dark Ages of home audio. They were right,  it was just the beginning, then came MP3, free downloads and “most folks cannot hear the difference” brainwash.

Another unique characteristic of D-90 is its short life-span. With some luck there is still a chance to get D-50, the very first Discman, in perfect working condition.  But ALL original D-90 are dead by now. 100% of surface-mount electrolytic capacitors failed at some point between 1990 and 2015. Bad batch of SMD electrolytics? Probably…

One weird technicality not found in any other Discman is that Right channel has 4.7uF/16V “thru hole” electrolytic capacitor in the signal path, but Left channel has 4.7uF/35V surface-mount cap. This SMD cap (C220 on schematics) fails first. When restoring D-90, I always substitute failed C220 for “thru hole” 4.7uF/16V Rubycon electrolytic. I do not care if I can hear the difference or not, both L and R channels must pass through the same parts.

Below is a step-by-step Resurrection procedure for D-90. This is the first thing you see once you remove the bottom plate:

desolder six CD transport wires (spindle and sled motors and center-stop switch) plus one ground wire, disconnect two flex boards and flip the main board:

Mechanical problems must be dealt with first. The infamous “middle gear” must be removed, cleaned and re-lubed. Its brass pin must be polished, a strip of 1,000 Grit sandpaper and a loop of a cotton thread usually does the trick:

new spindle motor guarantees another decade of smooth play:

All SMD caps (red marker) are dead and must be removed. Red arrows point at mismatched C220 and C120 caps:

Once all leaking/old caps had been removed and board cleaned, it is a good idea to make sure that all traces of acid got neutralized. Use a sludge of household baking soda, then wash the board with isopropyl alcohol:

All power caps and analog circuit caps (blue marker) were exchanged for fresh Rubycon and audio-grade Nichicon electrolytics:

This particular D-90 received the famous Black Gate coupling capacitors (black arrows), the last electronic part between CD player and the headphones. You may also notice that now both C220 and C120 (red arrows) are of the same type and value:

Fun part of restoration process:  electric adjustment and laser re-calibration:

More info, especially on laser exchange and alignment can be found at www.kaosuncd.com

The final step of Resurrection/rejuvenation process is a “break in”. Discman is set for hours of continuous play: