The Logic Off Topic list

> From: Marvin Humphrey <marvin@...>
> Reply-To: logic-users@yahoogroups.com
> Date: Sun, 01 Jul 2001 10:18:40 -0700
> To: <logic-users@yahoogroups.com>
> Subject: Re: [LUG] [OT]  New silent & fast Seagate harddisk
> 
> marc lindahl:
> 
>> Also, I wonder about the longevity of fluid bearings -- if it's like an
>> automatic transmission the fluid could break down....
> 
> In the long run, all hard drives are ticking time bombs, compared to analog
> tape!  Just last week, we had some 1/4" tapes from 1979 in... they had to be
> baked, then the splicing tape adhesive which oozed had to be cleaned with
> q-tips and solvent, and finally it played back gorgeously!  How the hell do
> you get inside a hard drive to do that kind of restoration work as it
> degrades over decades?

You don't... the best long term format (practical) so far is optical - like
CDROMs, DVDROMs.  Longer lifespan than analog tape....

the nice thing about digital, if you have the time to do it, is if you make
bit-perfect backups, then you've 'reset the clock' on the lifespan,
something you can't do with analog.


> 
> PS: Here's something wacky: I hear that of all the current digital tape
> formats, the one with the greatest long term stability is ADAT, because it
> has the lowest information density.

assuming you can get access to a working deck 15 years from now :)

> 
> -- Marvin Humphrey
> Mastering Engineer and Graphic Designer, emeritus
> CD design website - http://marvin.mrtoads.com
> 
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> > marc lindahl:

> > In the long run, all hard drives are ticking time bombs, compared 
to analog
> > tape!  Just last week, we had some 1/4" tapes from 1979 in... they 
had to be
> > baked, then the splicing tape adhesive which oozed had to be 
cleaned with
> > q-tips and solvent, and finally it played back gorgeously!

  You must have liked the way it sounds, but are you sure about how 
close it is to the way it sounded in '79. Phasing, transients, and 
speed are a guess at best to what was originally printed after all 
that time.

  Plus after all that work, getting it to playback so "gorgeously", I 
hope you made a digital copy of it. Atleast on a cdrom, or even a hard 
drive somewhere.

df

marc lindahl:

> the best long term format (practical) so far is optical - like
> CDROMs, DVDROMs. 

I'm curious about DVDr... Does it work on the same burn-dye-to-imitate-pits
strategy as CDR?  I like the idea of DVDr, but I'm not sold that
miniaturized CDr technology boasts the same reliability or longevity as full
size.

> Longer lifespan than analog tape....

Hmm.  The problem is that digital degrades so ungracefully.  Shannon's
theories allow you to predict how much EC overhead you'll need to insulate
the information from the noise of the "noisy channel", but your calculation
becomes invalid as the noise in the storage channel increases over time.
All of a sudden, the EC fails, and you have dropouts.  Depending on how the
information is organized, this commonly results in complete dropouts in the
reconstructed waveform or huge glitching.

In contrast, when analog magnetic media goes south, you may get HF loss, or
warbles, but by and large, the perceptual effects are not as severe.  Also,
sticky-shed syndrome does not affect all tape formulations.  We just played
back somebody's acetate tape from the 60s with no conditioning other than
repack onto a better reel.

Interesting tidbit: "scalable" codecs implemented as part of MPEG 4 behave
more like analog media, as dropouts result in a momentarily degraded signal
rather than total loss.  As packets are lost, the sample rate gets cut back,
and the coding gets rougher, but the signal doesn't go away completely.

Here's a neat link that talks about the need to analyze the types of errors
that your system will experience if you're to optimize it for best
performance:

http://www.ednmag.com/ednmag/reg/1997/110697/23df_06.htm

The problem with all of the storage solutions that digital audio sponges off
the computer industry is that no one in computer R&D has market pressure
driving them to think about making storage that lasts decades or centuries!

> the nice thing about digital, if you have the time to do it, is if you make
> bit-perfect backups, then you've 'reset the clock' on the lifespan,
> something you can't do with analog.

It can be done, but will it be done?  Risky thing to assume.

Back to the original subject:

These Seagate drives with the fluid bearings... your misgivings are in
regards to short term reliability, I assume.  Mean time failure rate...
Since it's a new technology, wait-and-see is probably a good idea...

But imagine one of those Apple G4 Cubes outfitted with a quiet HD... no fan
noise, no HD noise (supposedly).  You could actually have one of those in
the room with you as you record.  A lot of DIYers have been waiting for that
for a while.

-- Marvin Humphrey
Mastering Engineer and Graphic Designer, emeritus
CD design website - http://marvin.mrtoads.com

> From: Marvin Humphrey <marvin@...>
> 
> I'm curious about DVDr... Does it work on the same burn-dye-to-imitate-pits
> strategy as CDR?  I like the idea of DVDr, but I'm not sold that
> miniaturized CDr technology boasts the same reliability or longevity as full
> size.

I believe it's phase-change.  Dunno about reliability.  BTW, the AES
(http://www.aes.org) has a working group on archiving and restoration.

> 
>> Longer lifespan than analog tape....
> 
> Hmm.  The problem is that digital degrades so ungracefully.  Shannon's
> theories allow you to predict how much EC overhead you'll need to insulate
> the information from the noise of the "noisy channel", but your calculation
> becomes invalid as the noise in the storage channel increases over time.

Well, the calculation doesn't become invalid, if you account for degradation
over time as well. 


> All of a sudden, the EC fails, and you have dropouts.  Depending on how the
> information is organized, this commonly results in complete dropouts in the
> reconstructed waveform or huge glitching.

True.  But if you have multiple copies, the probablity of them all failing
at the same point decreases exponentially, and since it's digital, as long
as you have a known good copy of every sample, you can perfectly reconstruct
the whole.  While something similar is theoretically possible with analog,
in practice there wouldn't be enough copies around to even try it.

> 
> In contrast, when analog magnetic media goes south, you may get HF loss, or
> warbles, but by and large, the perceptual effects are not as severe.  Also,
> sticky-shed syndrome does not affect all tape formulations.  We just played
> back somebody's acetate tape from the 60s with no conditioning other than
> repack onto a better reel.

True, the graceful degradation is appealing.  I believe some form of disk
holds the longevity record, either acetate or phenolic or something... and
wire recordings.  Vinyl records if properly stored can last way longer than
tape.



> The problem with all of the storage solutions that digital audio sponges off
> the computer industry is that no one in computer R&D has market pressure
> driving them to think about making storage that lasts decades or centuries!

True, but there is a small and growing movement even in the biz sector as
records are digitized, people are starting to wonder what's going to happen
to them.


> It can be done, but will it be done?  Risky thing to assume.

Another approach that I alluded to above is to make many copies at the time,
and ideally distribute them geographically.  THere's more to archiving than
media longevity -- what if the building burns down!


> These Seagate drives with the fluid bearings... your misgivings are in
> regards to short term reliability, I assume.

Well, more like 5-10 year timeframe.  I still have some hard drives in
operation from the 80's!


> But imagine one of those Apple G4 Cubes outfitted with a quiet HD... no fan
> noise, no HD noise (supposedly).  You could actually have one of those in
> the room with you as you record.  A lot of DIYers have been waiting for that
> for a while.

True, it would be nice... until and if solid state memory gets cheap enough!

david@...:

> You must have liked the way it sounds, but are you sure about how
> close it is to the way it sounded in '79.

Well, I didn't have an LP to compare it to, but fwiw, it did sound
remarkably similar to a conservative CD mastering job that was performed in
1995.

> Plus after all that work, getting it to playback so "gorgeously", I
> hope you made a digital copy of it.

24 bit files, archived to CDrom.  Multiple copies provided to client.
Geographically dispersed storage recommended.

-- Marvin Humphrey
Mastering Engineer and Graphic Designer, emeritus
CD design website - http://marvin.mrtoads.com

marc lindahl:

> While something similar is theoretically possible with analog,
> in practice there wouldn't be enough copies around to even try it.

Amusing anecdote: Bruce Swedien reports that there were over a hundred mixes
printed of Michael Jackson's "Billie Jean". They ended up going with mix #2.

>> The problem with all of the storage solutions that digital audio sponges off
>> the computer industry is that no one in computer R&D has market pressure
>> driving them to think about making storage that lasts decades or centuries!
> 
> True, but there is a small and growing movement even in the biz sector as
> records are digitized, people are starting to wonder what's going to happen
> to them.

The movement of critical servers to nuclear bunkers is a harbinger of things
to come, perhaps.

>> It can be done, but will it be done?  Risky thing to assume.
> 
> Another approach that I alluded to above is to make many copies at the time,
> and ideally distribute them geographically.  THere's more to archiving than
> media longevity -- what if the building burns down!

"Off-site storage" is where it's at! ;)

-- Marvin Humphrey
Mastering Engineer and Graphic Designer, emeritus
CD design website - http://marvin.mrtoads.com

Does any one know what the ultimate conditions CD Roms would like to 
be stored under?  How about refrigeration.  That slows down most 
chemical processes.  Does freezing ruin them?    I guess I could 
check this myself.
-- 


                                 Dennis Gunn
                                 Mightyjohn@...

                  check out  MIGHTY JOHN HENRY's album "hot air head"
                                                    info at
                        http://www.twics.com/~mightyjo/home.html

Lee Blaske:

> Are you using hard drives as an archival medium? That would be pretty odd.

I do not.  I know people who do, and people who have but don't anymore.  It
is not done for reasons of longevity, but for convenience or economy.  False
economy, one might say, but I don't get to dictate what people archive to.

> Properly cloned digital data, however, should suffer no loss.

You won't have to work hard to convince me of that!

> I believe properly maintained digital data has the best potential for
> long-term preservation. Obviously, you've got to clone before the
> storage medium suffers any degradation,

And that's the rub.  When you miss the "clone by" date, it all goes to hell.
And because accelerated aging tests aren't perfect, the clone-by date could
be closer or farther away that we suspect - who knows?.  You're concerned
about the financial future of Alesis and the future of ADAT (rightly so; I
only mentioned the ADAT tape bit as an FYI), but not about the stability of
whatever institutions/individuals wind up holding digital archives?  When
they find the old CDR archives in the attic... uh oh.  And even if archives
wind up in the hands of responsible institutions, they may not be perfectly
financially stable in every year, or mistakes may be made.  Digital as it
currently exists is extremely unforgiving.

> Also, for anyone interested in long term access to original session
> audio, I think it's very important to archive original, contiguous
> tracks (beginning from a common start point) rather than simply
> keeping a Logic session. It would be great if Logic is still around
> years from now and is able to maintain backward compatibility over
> many decades, but I wouldn't count on it.

Alternately, AES31 EDLs will be openable far into the future.  Logic can't
export those yet though.  Prediction: eventually, it'll have to.

f-erenc szabo wrote, in another message:
> If you're worried about the long term storage of, say, CDr
> then simply make another clone of it every few years.  This
> is vastly easier to do than the baking/solvent shenanigans
> needed for analog tape.

Until the data is irretrievably lost because the CDR was forgotten for a
decade or so.  Baking a CDR that's gone south won't help. :(

I will be interested to see what long term solutions are developed for
holding digital.  From what I've read of communication theory, it's going to
be an uphill battle.

-- Marvin Humphrey
Mastering Engineer and Graphic Designer, emeritus
CD design website - http://marvin.mrtoads.com

--- In logic-ot@y..., Marvin Humphrey <marvin@r...> wrote:
> > I believe properly maintained digital data has the best potential for
> > long-term preservation. Obviously, you've got to clone before the
> > storage medium suffers any degradation,
> 
> And that's the rub.  When you miss the "clone by" date, it all goes to hell.
> And because accelerated aging tests aren't perfect, the clone-by date could
> be closer or farther away that we suspect - who knows?.  You're concerned
> about the financial future of Alesis and the future of ADAT (rightly so; I
> only mentioned the ADAT tape bit as an FYI), but not about the stability of
> whatever institutions/individuals wind up holding digital archives?  

I've been hearing about this for a couple of months on these lists, about Alesis having financial problems. Though I haven't found information about this anywhere. Is this a rumour, or is there a palce on the net where I can read more about this?
Even if Alesis would go down, there would still be some companies willing to take over their technology. Maybe Alesis will end up in the hands of Creative then, :-)(ouch). Just like Emu and Ensoniq did. Would be better if Alesis became property of Yamaha, like Korg is.
So rumour or not?
Regards,
Yoonchi.

Dennis Gunn said:

>Does any one know what the ultimate conditions CD Roms would like to
be stored under?  How about refrigeration.  That slows down most
chemical processes.  Does freezing ruin them?

I have six CDs in the auto-changer in the car that I burned.  Nighttime
temperatures in the winter occasionally drop to freezing and daytime
temperatures in the summer (with car windows closed) go over 50C, sorry I
can't remember what that is in F, either way it's extremely hot!

This 'test' has been going on for over three years and all discs play fine;
which is not what I was expecting.

Tim ;o)

At 8:11 AM +0300 7/3/01, T Rainey wrote:
>Dennis Gunn said:
>
>>Does any one know what the ultimate conditions CD Roms would like to
>be stored under?  How about refrigeration.  That slows down most
>chemical processes.  Does freezing ruin them?
>
>I have six CDs in the auto-changer in the car that I burned.  Nighttime
>temperatures in the winter occasionally drop to freezing and daytime
>temperatures in the summer (with car windows closed) go over 50C, sorry I
>can't remember what that is in F, either way it's extremely hot!
>
>This 'test' has been going on for over three years and all discs play fine;
>which is not what I was expecting.
>
>Tim ;o)
>
Thank you for the info.  I have often wondered what exactly goes on 
in the "accelerated aging tests" .  I guess they just use your car.
-- 


                                 Dennis Gunn
                                 Mightyjohn@...

                  check out  MIGHTY JOHN HENRY's album "hot air head"
                                                    info at
                        http://www.twics.com/~mightyjo/home.html

marc lindahl:

> BTW, the AES (http://www.aes.org) has a working group on archiving and
> restoration.

And we are just about out of my depth and into theirs.  I'm not motivated
enough on the subject to learn the chemistry!
 
>>> Longer lifespan than analog tape....
>> 
>> Hmm.  The problem is that digital degrades so ungracefully.  Shannon's
>> theories allow you to predict how much EC overhead you'll need to insulate
>> the information from the noise of the "noisy channel", but your calculation
>> becomes invalid as the noise in the storage channel increases over time.
> 
> Well, the calculation doesn't become invalid, if you account for degradation
> over time as well.

Nicely said.  If long-term considerations were to be given weight in
research, it ought to be possible to design digital media optimized for
archival.  If you know you'll have spots of a certain size, or if you know
it will degrade at the edges... whatever.  The challenges are primarily
chemical and material; the information theory analysis and EC design is
straightforward.

> if you have multiple copies, the probablity of them all failing
> at the same point decreases exponentially, and since it's digital, as long
> as you have a known good copy of every sample, you can perfectly reconstruct
> the whole.  

I thought a little more about this.  If all the copies are created at the
same time, and they all experience a crash-knee type degradation around the
"expiration" date, then all copies might be completely unrecoverable.

-- Marvin Humphrey
Mastering Engineer and Graphic Designer, emeritus
CD design website - http://marvin.mrtoads.com

Dennis Gunn said:
>2.  The heads of the drives do not actually
contact the medium the way the heads of a tape machine do so even if
the binding medium does get a little weak it probably is not as big
of an issue as with tape since there is nothing trying to rub it off.

If the binding becomes weak couldn't centrifugal force be enough for the
oxide coating to become displaced?

And:
> Thank you for the info.  I have often wondered what exactly goes on
in the "accelerated aging tests" .  I guess they just use your car.

No wonder my insurance has gone up :)

Tim ;o)

At 11:41 AM +0300 7/3/01, T Rainey wrote:
>Dennis Gunn said:
>>2.  The heads of the drives do not actually
>contact the medium the way the heads of a tape machine do so even if
>the binding medium does get a little weak it probably is not as big
>of an issue as with tape since there is nothing trying to rub it off.
>
>If the binding becomes weak couldn't centrifugal force be enough for the
>oxide coating to become displaced?

Wondered the same thing myself.  Somehow it doesn't seem likely but I 
really don't know.
-- 


                                 Dennis Gunn
                                 Mightyjohn@...

                  check out  MIGHTY JOHN HENRY's album "hot air head"
                                                    info at
                        http://www.twics.com/~mightyjo/home.html