Any thoughts on the CD "trimmer"

The purpose of the AudioDesk Systeme CD lathe is not to true discs that may be slightly eccentric, it is to trim the edge at an angle so light does not reflect back into the disc. It comes with a permanent black marker to mark the trimmed edge and the center hole for further reduction of reflection. I hear differences on every disc, some more than others. Resolution and soundstaging are improved, as well as bass being more defined and tuneful.

I've always found it interesting that a CD can deliver 40 million lines of code (i.e., Windows XP OS) yet cannot be counted on to accurately deliver the zeros and ones on a music CD without special procedures.

The only way light can cause errors bouncing around inside a CD player is to disrupt the accurate deliver of those zeros and ones - either some show up missing or extras are added. If true, this would make the installation of a computer program or the reliable storage of data impossible.

There are certainly a lot of things a good audio CD player can do to improve the sound quality it delivers, but I don't think stray light bounces are one of them. If stray light could cause this problem, then the audio CD player engineers need to walk across the hall and find out what their data computer buddies are doing better.

Missti, ask Krell about how I discovered that overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport effected the bit stream to the D to A converter.

Stray light, bounced light and vibration are all real. The CD player must work harder to get the data correct when it meets these forms of interference. Yes, it still delivers good sound but there IS a difference and that's what most audiophiles are seeking.

So, if a tweak helps a little and the perfectionist can hear it (for instance Essentialaudio), they are availing themselves of better quality and passing along the experience to others that want to get that last bit of music.

If you can't hear it, be happy and don't spend the money.

I use the "trimmer" for years and I would not want to miss the effect anymore this short procedure has on sound improvement. As said above: some CDs benefit more than others. And played on my Wadia 270 makes the difference bigger than played on my Sony 557.

the black marker technique is not necessarily a good thing. Certainly a difference can be heard when playing a 'blacklined' disc vs. not lined. I didn't believe it either, but I actually tried it before posting opines that it simply cannot work; it does work. However I discovered that the marker technique actually caused changes in the sound that I didn't like, so I removed the marker with alcohol and the sound reverted to its' original state.

Same result for the Auric Illuminator product. It certainly does change the sound, but not necessarily in a good way. I'm glad that the product is also removeable.

You have to remember that the ones/zeros are not digitally encoded, they are contained within an analog modulated carrier envelope which is detected via laser pickup & decoded back into digital. Certainly there are numerous causes of bit error degradation along this circuitous path.

Mlsstl: Everything is "impossible" until someone tries to do it and find out that it is "possible". Have you ever actually tried using the Audio Desk Systeme? Sean
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Albert wrote:
>> Missti, ask Krell about how I discovered that overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport effected the bit stream to the D to A converter. <<

That may be so, Albert, but the fact is that the VAST majority of CD players pull the disc inside the machine's case. So, please explain to me just how "stray" light is getting inside the player?

-RW-

We're still back to the issue that programming code and data are accurately delivered by CD binary code in CD players but if that code in the same format is delivering music, it becomes corrupted.

As for the Krell MD10, the thing has a clear plexiglass top! There is an old saying that the "poison is in the dose." That particular example strikes me as a victory of visual appearance over function. (And, BTW, halogen light power supplies are an excellent source of EMI/RFI.)
As for "ones/zeros are not digitally encoded, they are contained within an analog modulated carrier envelope..." I do not believe that is a technically correct description of the digital recording and storage process. Certainly there can be vast differences in the quality of AD and DA conversion (and subsequent preamplification for analog output) but that is a separate issue from whether the binary code is accurately extracted from a CD.

I'd suggest that all of this theorizing is not helping the original poster. Y'all should read the Audiodesksysteme website to get an accurate idea of what this system does.
A review was published in a British HiFi magazine recently that explains the process also, and the reviewer purchased one.
I have heard discs treated by this system, and it really does work. It does improve the sound, and CDs that sounded nasty/edgy sounded much better after treatment.

Mlsstl you can theorize as much as you like but the proof is in actually listening.It is not difficult to hear the changes in sound produced by using the Audio Desk Systeme. It is easily audible with any system.

> It is not difficult to hear the changes in sound produced by
> using the Audio Desk Systeme.

For the technical details of the error correction of binary data storage on an audio CD, see http://www.ee.washington.edu/conselec/CE/kuhn/cdmulti/95x7/iec908.htm which describes the IEC 908 standard that applies to every music CD you buy. (The Audiodesksysteme web site offers no technical information at all.)

Guess we'll have to agree to disagree about the impact. I've not heard a CD processed with this specific device but have had other systems that ostensibly improve the "scattered light" situation of a CD playing inside a player and have heard no change I can ascribe to that change.

I've also compared the audio quality of CD's to bit-for-bit verified hard drive copies (which involve zero light of any kind) and heard no differences (if the CD has not been damaged.)

However, I am also aware that when I am listening critically, I can move my head a couple of inches side to side or forward and back and hear subtle changes in the quality of the reproduced music. Forgetting the psychological issues that can affect our perception, there are certainly real issues that affect how things sound to us. I just don't think this is one of them.

However, this is one of the nice things about this hobby. I don't have to use the device to satisfy someone else's demands and they don't have to not use it if they believe it is working for them.

Mlsstl, I am totally with you. Oh, by the way, check out all the "crazy expensive" systems (more than $150,000)with pics on this site, that have speakers place directly next to windows, and/or with the speakers obviously too close to each other to produce a proper stereo effect. Some people suffer from the "just gotta have it" disease.

Mlsstl: I purchased one of these units from a local audio store with full return privileges. After making direct comparisons with identical discs i.e. one "cut" and the other "uncut", the audible difference made me decide to keep the unit.

As a point of reference, i had my girlfriend ( at the time ) sit and listen to both identical discs, one cut and the other uncut. She had NO idea what was going on, and as such, could not have known which disc was "cut" and which wasn't. When i asked her which disc she preferred, if any, she always chose the cut disc. Her explanation was that "it sounds clearer".

To my ears, and several others that i've tried this test with, the results are almost always the same. Some folks can't hear any difference and to them, i simply say "count your blessings". After all, "ignorance is bliss" i.e. not knowning what they are missing because they simply can't hear it. While some might consider a loss of hearing acuity more of a curse than a blessing, the blessing part comes from the fact that it can be a whole helluva lot cheaper : ) Sean
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Rlwainwright

That may be so, Albert, but the fact is that the VAST majority of CD players pull the disc inside the machine's case. So, please explain to me just how "stray" light is getting inside the player?

Obviously CD's pulled inside or otherwise blocked from stray light are exempt from that problem. The post by Missti indicated errors were impossible and I wanted to point out an absolutely clear example contrary to that statement.

My personal experience with this machine matches Sean's comments exactly. Perhaps others will remember the CES a couple of years ago where an Audiodesk was set up by the distributor. Attendees could get one or more of their CD's trimmed for free so they could hear the benefit.

Several people bought two brand new CD's from music vendors on the floor, had one trimmed, then proceeded to various rooms where both discs were played. Results were identical to what Sean outlines, I heard it myself as did other visitors in the room that had no idea what was going on.

Remember too, I am a fan of analog and seldom listen to CD's. However, I do support those who want the highest possible level of performance from their music systems and that includes tweaks to digital.

This is the kind of info I had hoped for,when posting.Thanks to all.
IMO,the issue is sort of like the debate about aftermarket fuses,of the expensive variety.Many variable opinions,and I wanted SO to not get them.Well the proof was in my own experience,and as a friend purchased them,they were CLEARLY superior,in his(I have same unit)pre/phono section.Case closed!EXCEPT...in this case we are talking of a device costing more than a few bucks.And,once again,taking all the technical babble out of the equation,can sound a bit silly.
SO,I and my pal called a dealer,we have bought a good deal of stuff from,who carries the "trimmer".He has used it,and we inquired as to his thoughts,since we were/are interested in it(BTW,I am mostly a vinyl guy,but do feel CD is indispensible,for new music,and music comes first).
Well,here was a chance to garnish a double sale,yet SURPRISINGLY,this dealer actually tried talking us out of a purchase,and did not try to sell us anything else!
Whoa!How often do we see this?He explained that,in his experience,he and his associates cannot hear the differences between a cut vs uncut(OK,trimmed) disc.The guy has ben around for a long time,too.Hence,my post.
I am still on the fence here,but my pea sized brain is still in the process of evaluating other opinions,before making a final decision.
Best!

The process works! Find someone who has one; listen to your CD untreated and then then his that has been trimmed. It is an amazing tweak. Forget the marker; it isn't needed. After cutting your collection cryogenically treat them which is the next best inexpensive tweak there is. Your sound stage will will have a blacker background and smoother presentation.

sirspeedy: If you want, you can send me a disc or two and i can trim them for you. That is all that i will do though, as i do NOT believe that markering them up is beneficial. In fact, in my experience, it has been a drawback. Anything that you want to do after that is obviously at your discretion. The only thing that i ask is that you include return postage fees if / when you ship the discs to me. Sean
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sirspeedy70680@earthlink.net,
Here are a few more comments on the subject.
http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1051384332&openfrom
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Jim

Anybody: I've never messed around with treating CDs in any way. But to those who've found a difference (good or bad) treating them with markers, how exactly should I go about this tweak if I want to experiment? I'll burn 2 copies of a test disk, treat one, and compare the treated and untreated versions and post back here.

Albert: You say Krell confirmed your finding that "overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport, affected the bit stream to the D-to-A converter". This implies that they actually found a change in the measured datastream, and also that they controlled for any effect that such lighting fixtures may have on the powerline (presumably by measuring the data with the lights on, versus with the lights still on, but blocked from shining into the player). I hope that is the case, otherwise it seems to me no causal link could be established. Of course, as you also indicated, either way this probably has little relevance for the vast majority of disk-players made.

Mlsstl: You wrote "I've also compared the audio quality of CD's to bit-for-bit verified hard drive copies (which involve zero light of any kind) and heard no differences". While I can't do the bit-verification thing, using my Alesis MasterLink with its digital output fed to a Theta DAC, I've compared the 'live' playback of CDs with that of the same CDs ripped to the unit's internal hard-drive, and they don't sound the same (the hard-drive sounds better -- but both sound inferior to the same CDs played 'live' on a Theta transport).

Thanks for the good natured responses.I'll ponder this.

Best!

Is it possible that the Audiodesksysteme treatment improves the timing of the digital raw data, i.e. the jitter becomes less if treated CD's are played?
For the owners of this device and PC w/ digital out & DAC, may I suggest an experiment: rip a treated and untreated CDs to the harddrive, do a bit comparison, and send the ripped track file from the PC to the DAC. Do they still sound different? From what I read and my understanding of optical storage, I suspect the difference only arises during real-time playing.

Albert: You say Krell confirmed your finding that "overhead halogen lights, shining through the Plexiglas lid of their MD10 CD transport, affected the bit stream to the D-to-A converter." This implies that they actually found a change in the measured datastream, and also that they controlled for any effect that such lighting fixtures may have on the powerline (presumably by measuring the data with the lights on, versus with the lights still on, but blocked from shining into the player).

One of our music night sessions I accidentally improved my Krells performance by resting a record album cover on it's top.

The CD was still playing and I was putting the LP on the turntable and we all heard the improvement. At first we all thought the tiny additional weight of the cardboard was somehow damping the chassis.

After repeated tests we determined the same effect could be had by holding any light blocking device above the player even when we were not touching the player or turning the lights off.

I told Krell about my experience and at first they did not believe me, later they acknowledged there was an effect and they treated the interior of the player with light absorbing material and added a heavily smoke colored tint to the Plexiglas.

Oddly enough, a guy my audio group has a very late model Krell player and while visiting him a month ago I ask for a magazine. He brought it in the room, we continued to listen and then I laid it on top, blocking his halogen room lighting.

There was an improvement and he was totally surprised. Not nearly as big as with my old Krell but audible enough that he cut a fancy piece of cardboard to fit the player and now keeps it handy when listening.

People love to make fun of tweaks but often it's just an improvement by accident that solves a problem nobody even knows exists.

I posted a thread about this thing last year :
http://forum.audiogon.com/cgi-bin/fr.pl?htech&1113147370&openfrom&1&4#1

I'm deciding to kick out for the machine, a di$count would be kinda nice.

I'd like to uniformly trim my CDs to the *same outer diameter* for my
De Mat, so the lip of it goes over the edge of all my discs, not 80% of them.

So if this thing is a "lathe" I should be able to use it as such, not just for the "beveled edge"

Elizabeth's post is echoed by Loontoon in my thread.

sirspeedy: I know you asked for feedback on whether or not the Audiodesk trimmer improved sound; however, I also want to share the positive effects it has on DVD's. Resolution and color is noticably improved. I use my Audiodeske for both CD's and DVD's (with a front projector and upsampling DVD player in a dedicated HT).

WOW!!This is all enough "patchkaing" to reinforce to me that vinyl is an easier medium to enjoy,afterall!!

Just kidding,but we all thought lp spinning was a pain in the tush,now check out all these processes to get the most from a crummy CD.
How about making the venerable silver disc "better"?
Best!

Thanks Albert. Not saying I either doubt or believe your hypothesis, but those tests as you describe them aren't sufficient to establish causality (they don't measure the datastream, and aren't controlled to eliminate psychology as a possible cause). But I'm not very surprised that Krell decided there was indeed a problem (even if it wasn't known to be a measureable problem, it was still a potential PR problem due to audiophile word of mouth), though I am a bit surprised that they then didn't completely 'fix' it by simply installing a fully opaque cover.

My understanding is that one source of light the AudioDesk lathe trimming is meant to address are reflections from the laser bouncing around inside the CD transport, as well as any stray light from the outside (since many trays are not hermetically sealed).

Zaikes, I did not say Krell didn't measure the effect, I simply said they agreed there was a problem and fixed it. It does not matter that I didn't measure the effect, the change of blocking the light was enough of a problem that the manufacturer changed the design.

As for opaque cover, the transparent cover was a big part of the beauty and design of that piece. Swapping for a smoked version and darkening material inside increased performance without calling attention to the mods or admitting anything was wrong with the original. Frankly, this happens all the time in high end audio, it's just not brought to the attention of the consumer.

A CD rom drive (OEM) can cost under $5, and can read 700Mbytes without a single bit error, yet, apparently kilobuck CD players cannot do the same ?

I don't think bit errors are an explanation.

Some people have pointed out that the digital data is in fact an analog waveform, or eye-pattern. If the player derives its clock from the sampling of the eye-pattern and if the eye pattern is improved by felt markers or disk-trimmers then a sound improvement may be heard.

However, any modern kilobuck player that does not buffer and reclock data to decouple the data demodulation from the DAC clocks is IMO using outdated technology.

Take Meridian as an example, they use CD-rom drives, often with multiple read passes, and buffer the data through RAM, before using a separate low jitter clock to pass the data through the DACS.

If you've spent thousands on a CD player, and putting markers on the edge, or using a "lathe" improves the sound then my conclusion is that the CD player is not correctly designed. If you've spent $50 on a player and the sound is improved then that is more understandable.