Re: [ARSCLIST] CD-R error rates

[Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>]

Hi All:

George is onto something interesting here, if I understand him correctly. There seems to be an issue 
with center-holes on different blank media and cheapos seem to be more liberal about compliance.

Here's how I found this out. At my office I like to listen to music all day in the background. I was 
thrilled when a friend gave me an old Fisher 60CD jukebox player. Thrilled anew when it turned out 
to be just fine with CDR media even though it was circa 1992. So I started loading it up. It's a 
sideways-mounted transport, not the usual horizontal kind. So gravity is now the enemy of good disc 
rotation, as opposed to being an ally in the horizontal position (by providing downward force to 
help counteract spin anomolies). Wouldn't you know it, about half the discs I would load in wouldn't 
spin right. You can hear it loud and clear that it's not smooth even rotation, that something is 
off-center and making the disc jump around on the spindle. Given it's a 1992 lower-end player, it 
just plain can't play discs that don't load and spin correctly. I finally weeded out all the bum 
discs and kept them in a pile. Almost all of them were the cheapo generic "Ridata" green-dyes we use 
to mass-dupe our conference transcripts onto. Now, I've never had a problem duping these at high 
speed (and I do use a bit-to-bit verify routine in the duper after the burns) and we've never gotten 
one returned as not working (except for the batch our duper-dope [me] labelled and then didn't 
actually burn content onto). So I took the lid off the player and loaded up one of these discs so I 
could watch the player mechanism. Sure enough, the disc loads in just fine, like any other 
properly-working disc. But the center hole appears to be just slightly larger than the spindle can 
seat tightly so the disc rotates off-center (and makes quite a racket doing it). This problem also 
happened with most but not all of a batch of Sony 700mb green-dyes that were most likely purchased 
on sale at Staples. The problem was not seen on any Maxell green-dyes loaded in nor on any T-Y or 
"Klone" blue-dyes. It was also not seen on old "Hi-Tek" blue-dye 74-minute discs made years ago.

So I think you can get all sorts of problems if your drive or player is sensitive to precise 
center-hole size and the burner drive wasn't so therefor the disc burned just fine. I noticed that, 
for instance, my Tascam CD recorder in the studio is not only horizontal but also clamps the center 
of the disc with what seems like more force than the vertical drive in the Fisher CD jukebox.

-- Tom Fine

----- Original Message ----- 
From: "George Brock-Nannestad" <pattac@xxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Monday, January 07, 2008 6:05 PM
Subject: Re: [ARSCLIST] CD-R error rates


> From: Patent Tactics, George Brock-Nannestad
>
> Jerry Hartke wrote:
>
> > No effect on measurements other than eccentricity.
>
> ----- may I then conclude that either your hub is excentric or there is a
> ring-shaped gap between the centre hole and the hub?
>
> > I did state "Our high-end Clover system gives very consistent results,
> > and results closely agree with Philips calibration discs."
>
> ----- yes, you did, but you did not define "consistent". The Philips
> calibration discs are a fabulous tool, but they do give much information, and
> you did not specify which. Perhaps they have centre holes at the lower end of
> the tolerance.
>
> Kind regards,
>
>
> George
>
> > Jerry
> >
> > > -----Original Message-----
> > > From: Association for Recorded Sound Discussion List
> > > [mailto:ARSCLIST@xxxxxxx] On Behalf Of George Brock-Nannestad
> > > Sent: Monday, January 07, 2008 4:54 PM
> > > To: ARSCLIST@xxxxxxxxxxxxxxxx
> > > Subject: Re: [ARSCLIST] CD-R error rates
> > >
> > > From: Patent Tactics, George Brock-Nannestad
> > >
> > > Hello, again,
> > >
> > > I am sorry, but neither Parker Dinkins nor Jerry Hartke have answered my
> > > question, which may be summarized as: what are the deviations in
> > > measurements
> > > on the same disc, same diagnostic system, but different placement of the
> > > CD
> > > on the hub.
> > >
> > > All that was given was otherwise useful information that warm-up may be
> > > important.
> > >
> > > Kind regards,
> > >
> > >
> > > George
> > >
> > > P.S. We have just bought new bathroom scales, 100 g resolution. However,
> > > stepping up, down and up again sometimes gives a deviation of 500 g
> > > between
> > > measurements. We are not going to hang on to these scales.
> > >
> > > ---------------------------------------------
> > >
> > > > Our high-end Clover system gives very consistent results, and results
> > > > closely agree with Philips calibration discs. Warm-up time is
> > negligible
> > > -
> > > > just long enough for a cup of coffee. The test drive uses a very
> > > reliable
> > > > Philips pickup head that is no longer available.
> > > >
> > > > Again, there are no "typical" results for testers. Each one is
> > > different,
> > > > and reflects the nature of the test drive. Variations are by
> > > manufacturer,
> > > > by model number, and even by serial number.
> > > >
> > > > Jerry
> > > >
> > > > > -----Original Message-----
> > > > > From: Association for Recorded Sound Discussion List
> > > > > [mailto:ARSCLIST@xxxxxxx] On Behalf Of George Brock-Nannestad
> > > > > Sent: Monday, January 07, 2008 12:28 PM
> > > > > To: ARSCLIST@xxxxxxxxxxxxxxxx
> > > > > Subject: Re: [ARSCLIST] CD-R error rates
> > > > >
> > > > > From: Patent Tactics, George Brock-Nannestad
> > > > >
> > > > > Jerry Hartke commented on Parker Dinkins, and I have a query:
> > > > >
> > > > > ----- has anybody tried to perform two or more consecutive tests on
> > > the
> > > > > same
> > > > > tester under two conditions: 1) do not cause any change of the
> > > position
> > > > of
> > > > > the CD on the hub (merely run the test several times) and 2) open
> > and
> > > > > close
> > > > > the drawer or physically rotate the CD on the hub by a known amount?
> > > > >
> > > > > Mechanical drive problems or at least the range to be expected in
> > any
> > > > test
> > > > > should be demonstrated that way.
> > > > >
> > > > > Kind regards,
> > > > >
> > > > >
> > > > > George
> > > > >
> > > > >
> > > > > Jerry:
> > > > > > Even expensive testers can give different results. Although
> > software
> > > > can
> > > > > > cause differences, the culprit is usually the drive. Anyway, E12
> > and
> > > > E22
> > > > > > error rates are far more important because they represent errors
> > > that
> > > > > are
> > > > > > approaching an uncorrectable state, and can result in read failure
> > > > after
> > > > > > degradation caused by handling and storage.
> > > > >
> > > > > >
> > > > > > >
> > > > > > > on 1/7/08 12:37 AM US/Central, Richard L. Hess at
> > > > > > arclists@xxxxxxxxxxxxxxx
> > > > > > > wrote:
> > > > > > >
> > > > > > > > So, looking at it this way, what is an acceptable C1 rate for
> > > > audio?
> > > > > > >
> > > > > > > Maximum of 220 errors per second, according to the inventors.
> > > > > > >
> > > > > > > > What are others getting?
> > > > > > > >
> > > > > > > > I had a client ask me how I was burning CDs earlier this year.
> > > > They
> > > > > > > > have some flavour of Clover analyzer and my CDs were showing
> > > lower
> > > > > > > > error rates than their in-house CDs--that was a pleasant
> > > surprise!
> > > > > > >
> > > > > > > Plextor/Plextools can be somewhat misleading as a test platform.
> > > The
> > > > > > > errors
> > > > > > > on our Stagetech EC2 run two to four times higher for the same
> > > > discs.
> > > > > > >
> > > > > > > --
> > > > > > > Parker Dinkins