CD trimmers, paint pens

[rfgumby]

Hi guys-
      So a little while back, my buddy said I should build a CD trimmer so that we wouldn't have to buy and try the Audio Systemdeske for entirely too much money.  Being up for a project, I took him up
on the challenge.  A couple days later I showed up with this:



A DIY CD trimmer.  It's pitched to bevel at about 38 degrees if I remember the desired number correctly.
You bevel the outside edge of the CD not unlike an Audio Systemdeske.  Except that uses a little lever with blades that wear out every so many CD's, etc.  So I built a dovetail top holder with an adjustable stroke, bolted it up so you could cut at different angles radially to the CD, and built up a sleeve and top around a disc motor I had.  An adjustable DC power supply fits in the base, and Bob's your uncle.



After the bevel you paint the edge of the CD with either the CD Stoplight green paint pens, or the black makers which are available at artist shops.  The idea is that you are preventing the laser from reflecting out towards the edges of the disc and back in again showing up as false readings.  It is suggested that that indeed happens and causes extra work for the error correction circuits in DACs (it is commonly correlated that the more the error correction circuits run, the worse the resulting sound).

Now I have formed my own opinions about how the green (and black) pens change the sound of CD's,
and also now have opinions of how beveling alters the sound.  Anyone else with any opinions about these procedures?

 

[jon]

None at all... It has been at least 6 months to a year since I last played a CD!

On the other hand that is just the most amazing device!

[willbewill]

Nice work Scott - do they sound better?

My favourite 'upgrades' to cd quality are:

Copy the cd to an Audio CDR - again less error correction required

Cut the inside of a 5 1/4 inch Floppy to fit on top of cd

[wesley]

   nice toy scott  .

i heard the effects of one of those cutters at a shop demo many years ago.  it did clean up the sound considerably, just like my green uniposca pen effect.  however to take it a step further, polish with pledge.  if the effect is even better with cutting and then green penning, then your more crazier than me  .

these days i only listen to cd's in my car for convenience sake......

[mfrench]

but how long before the in-dash cd player is obsolete?
(goes out and hugs truck cassette deck for its obsolete antiquity).

[rfgumby]

Well I'll give a few opinions...

   When I refer to the "green pens", you could use the Artist store black ones as well, the effect simply isn't as pronounced.

   I usually like the sound of the green pens on the outside edge and inside groove.  Most noticeable is the
"cleaning up" of the highs.

   The "sound" of the trimmed CD's alone is seemingly better than stock.  Not quite as much change as the green pens.  Effects are similar to the pens.  Once you hear the effect, it is relatively consistent between discs tested on.  Basically, the highs get far cleaner with less edge.

   The cumulative effects of trimming and painting seem too much (although I'm not entirely certain why that is, one would think less jitter would always be better), the green pen alone seems to do the job with less hassle, and less absolute roll off of the highs.  There is also the idea that once trimmed, it is easier for moisture and oxygen to enter the substrate of the CD through the outside edge, and potentially cause premature oxidation of the aluminum substrate.  Which would be bad.

  So, to summarize, if you like the effects of the green pens, don't bother with trimming.  If you are considering getting a trimmer, be sure to try the green pens first and insure that you like the effect.

[wesley]

thanks for the insight scott.

the effect of polishing with pledge takes it a step further, which cuts down on the refraction error.

[jon]

And of course there is always this

[wesley]

And of course there is always this

jon, that's a very interesting gadget.  there's some solid logic there, but considering the amount of money and effort, i'd rather be cheap and green pen and pledge.

cd to me will always be hamburger steak, not filet mignon  .

[hatehifi]

I bought a Glaess (Audio Sytemdesk) brand new used (about 10 CDs trial) for $200. The resale value is easily that here so I think I did well. I've got 2,000 CDs. One of our food discounters (Aldi) has weekly dry-goods sales and I picked up 16 black pens. I have 4 Stop-Light pens but picked them up for a song a couple of years ago in a hi-fi store close out. New, they are too expensive - therefore the black.

I agree (obviously) that the beveling smooths the edge off the highs and that green 'sounds' better but the cost margin is not worth it to me. If beveled, then the inside and outside edge covering is highly suggested. I think the 'combinaton' brings the sound to "the next level." I'm also in the market for a similar-buy de-magnitizer (e.g. Furutech) to replace my huge woofer magnet which I use (and hear a 'clarity' afterwards). That I use the SID (sound improvement disc) I've mentioned elsewhere. I also use Pledge or Perfekt Sound (depending on the price) and a micro cloth.

Its a pain in the butt but rarely can I hear more than a song or two without the 'spray' before I open the tray and use it. Beveling and edging happens before first play. It worth it to me. I hate digital 'grit' sound. I can really groove (albeit not as much as with vinyl) with my digital but it took me a long time to get to where I am now.

I plan to transfer all my CDs to hard drives (plus backup) in the coming months and then sell the originals. I hope the longevity (oxidation) doesn't happen before I unload them! Never heard of the problem but its too late for me to turn back...

[hatehifi]

While mentioning 'my' acceptable CD-sound I wanted to refer to a modification I had done on my second CDP a harman HD7725 and plan to have done before I start to 'store' my collection. It is an idea by YBA (the French company), namely, a strong blue LCD next to the CD pickup. I didn't do it to my third CDP (Spectral SDR 1000SL, last upgrade) because it sounded fine to me as was (thought it would have sounded better, I knew), but basically because of re-sale value - especially here.

However, my ModWright 9100ES SigTruth will get it. If I can't digitalize using it, then my darned PC will get a "blue light" show around its drive...

For me, a quick reference whether something sounds right or not is the piano. I also 'listen' for audible changes at a very (extremely) low volume. After the harman modification (the idea was published in the German Stereo magazine, years ago, btw) the piano was much more realistic.

It is easy to do, several high-output blue LCDs (different blue shades to find the 'right' one), some Litz wire and either a 9V battery or simply take the voltage off of an appropriate place from the CDP's board. Depending on the pick-up, you simply hot glue the LCD to it, facing towards the CD, direction of the laser. Voila!

[mred]

"green pens"... are we talking green sharpies or green ink and or paint?

I formerly would have put this in the category with other tweeks and would have donned my pointy tinfoil hat while listening...but I have to say that coming from this particular bunch of Heavenly folks I will have to try it.
One must keep an open mind. no?

Ed

[wesley]

ed, it has to be a opaque green ink.  i use one called uniposca (from mitsubishi).  it's a water based opaque green ink pen.  after the paint is dry in a couple of minutes, get a kiwi shoe polishing clean, spray a dime sized spot of pledge on it, then make circling motions from center outwards.  do not wipe in the circular motion of the cd.  it's a nice tweak, but then cd has it's limitation.  so much so that i'm putting up my tweaked out audio note dac for sale very soon.

[rfgumby]

"green pens"... are we talking green sharpies or green ink and or paint?

I formerly would have put this in the category with other tweeks and would have donned my pointy tinfoil hat while listening...but I have to say that coming from this particular bunch of Heavenly folks I will have to try it.
One must keep an open mind. no?

Ed

The green pens" are from Audioprism and available at a few retailers yet (think Audio Advisor and the like).  Those are the green paint pens with a color about that of a green screen they use for superimposing in television.  There are also a few other artist store pens in a medium green color which are purported to do the same thing.  The idea is that the specific color of green is the opposite of the laser color and is therefore absorptive at the laser light frequencies.  I've also heard black color in some ink pens works as well.

The more resolution of the system, the more obvious these changes are, but trust me- everybody I've ever done the comparison in front of said wow...  it is pretty obvious.  <psst- basically it rolls off some highs and cleans up sibilance>

Anything to help a CD, eh?

[hatehifi]

When I bought my almost brand new used Glaess edge beveler I read the instructions and saw that they suggest painting (Magic Marker - I use black but I assume green or red works too) not only the exterior and interior edges, but also the 'blank' on the play side up to and after the pits (recording) all the way to the center hole. NOT over the recorded portion. That is about 1/3 of the play side... with ~ 2/3 silver showing (e.g., if it is a standard AAD ~30 minute recording. Some of my DDD CDs are pitted, recorded over 90% of the play side).

Well, I confess that I still haven't tried that one but I did happen upon an interesting and viable finding. Before I had my beveler, I used to bring some stock CDs to my friend's Glaess beveler when I visited twice or so a year. He just painted the outer beveled edge and that was that and so I did mine. I recently thought this over and decided to experiment:

I took one of these and marked, painted just the inside parameter hole side (once around from the top and once around from the bottom). It sounded better.

I then painted this one on the play side from the center hole to the ring indentation (circa 1 cm). It sounded better.

I then held the disc up to the light and saw that the outside perimeter which was not beveled was also not painted (duh). So I paint this as well. It sounded better.

The before-and-after benefit of all of these steps is minimal but in total, especially between a new yet modified CD and the final product, is huge. It is like, but even more so, the difference between a professionally cleaned and uncleaned LP.

As I am right-handed, I now have a left-hand glove next to my Glaess as handling a freshly Magic Marker'd CD often leads to 'permanent' marks on my hand from handling.