Re: [ARSCLIST] CD Longevity (was Vinegar syndrome audio tapes [ARSCLIST] Memor

[Jerome Hartke <jhartke@xxxxxxxxxxxx>]

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Bob Conrad
> Sent: Saturday, January 21, 2006 9:57 PM
> To: ARSCLIST@xxxxxxxxxxxxxxxx
> Subject: Re: [ARSCLIST] CD Longevity (was Vinegar syndrome audio tapes
> [ARSCLIST] Memor
> 
> Jerome Hartke wrote:
> 
> >>-----Original Message-----
> >>From: Association for Recorded Sound Discussion List
> >>[mailto:ARSCLIST@xxxxxxx] On Behalf Of Charles Lawson
> >>Sent: Saturday, January 21, 2006 8:05 PM
> >>To: ARSCLIST@xxxxxxxxxxxxxxxx
> >>Subject: Re: [ARSCLIST] CD Longevity (was Vinegar syndrome audio tapes
> >>[ARSCLIST] Memor
> >>
> >>Bob Conrad wrote:
> >>
> >>
> >>>...j
> >>>ust found the listing on amazin' amazon. MAM-A is another name for
> >>>
> >>>Mitsui Advanced Media, and they market a 74-minute Gold Archive cd-r.
> It
> >>>
> >>>seems to retail for about $1.50 per disc, which is at least twice the
> >>>
> >>>amount that every other disc manufacturer gets. Also, it seems that
> >>>
> >>>there's no 80 minute version.
> >>>
> >>>
> >>Actually, there *is* an 80-minute gold version and it works just fine.
> I
> >>have been using Mitsui Golds on the National Symphony Orchestra's
> archive
> >>and broadcast CDs for years with few problems.  Since Mistui became MAM-
> A,
> >>the discs I have been getting are no longer manufactured in Japan and
> the
> >>quality control has been slipping.  Occasionally, one of the batch fresh
> >>out of the celophane will be horribly dirty with grimy fingerprints all
> >>over it.  So far, it has always been just *one* of the discs in a box of
> >>25 and it only happens occasionally, but it is weird.  The recorded MAM-
> A
> >>Golds do not always play reliably in cheap CD players, but they seem to
> be
> >>holding up well overall and data rip perfectly from them after several
> >>years.  I hope that result continues!
> >>
> >>
> >>>I've been using HHB because of it's supposed superiority in 1x
> >>>
> >>>recording, which is the only speed I use. Also, I've used Memorex Black
> >>>
> >>>
> >>>
> >>>from time to time.
> >>
> >>When I check the error rates using Plextor's software, I find that they
> >>are actually higher at 1X.  The current crop of discs appears to perform
> >>best in my drives at 4X.  8X is comparable.  I have found the worst
> >>results at 1X and above 16X.  My suspicion is that at the lower speeds
> the
> >>dye bleeds and causes more errors.  I haven't had the chance to check
> this
> >>out with an electron microscope, yet.  ;-)
> >>
> >>YMMV,
> >>
> >>Chas.
> >>
> >>--
> >>Charles Lawson <clawson@xxxxxxxxxxxxx>
> >>Professional Audio for CD, DVD, Broadcast & Internet
> >>
> >>
> >
> >Dye does not "bleed". The issues you describe are related to vibration in
> >the recording drive, not to the media. Excessive vibration can occur at
> high
> >speeds, while vibrations can be amplified when their frequencies approach
> >internal mechanical resonant frequencies of the drive at low speeds.
> >
> >Jerry
> >Media Sciences, Inc.
> >
> >
> >
> >
> I remember a number of years that some company had come out with plastic
> "rings" to attach to the outside of a cd disc, with the intention of
> this being able to stop/reduce cd vibration when the disc was being
> played.
> 
> I have no idea if this product actually worked, or if it is even still
> available today. But if so, would it in any way help cd-r's with the
> vibration problem you've described?
> 
> Bob Conrad
> Fort Lee, NJ

Although I have not evaluated the rings, it sounds like a bad idea. Such
attachments usually make a bad disc worse. Just like the attachment to your
car engine that will double your gas mileage but has been concealed by the
greedy oil companies.

I have observed significant vibration even with a disc that has minimal
unbalance. Much of the vibration results from drive spindle motor unbalance
and from imprecise centering of the disc on the drive spindle, not from the
disc itself.

Jerry