Conference rdvax::grateful

    How much does the copy-prevention stuff actually restrict DAT?
    I had heard that if you mastered on a non-"profe$$ional" deck,
    that you could only make digital copies directly from the master,
    never from the copies.  That is much more restrictive than necessary
    to safeguard the revenues of the record companies.  I am also not
    sure if this information is accurate.

Re:                        <<< Note 77.1 by WELCOM::ANDY >>>

>    How much does the copy-prevention stuff actually restrict DAT?
>    I had heard that if you mastered on a non-"profe$$ional" deck,
>    that you could only make digital copies directly from the master,
>    never from the copies.  That is much more restrictive than necessary
>    to safeguard the revenues of the record companies.  I am also not
>    sure if this information is accurate.

	You are correct the SCMS (Serial Copy Management System),
	invented I believe by Philips, sets control bits when
	copies are made from a digital master.  These control bits
	then inhibit further copying.

	I have heard rumours of a demonstration where a circuit made
	with about $15 worth of Radio Shack parts that intercepts and
	negates the control bits so that second generation digital
	copies can be made.

	Note, however, that analog copies can be made ad infinitum.

	Bob

re:         <<< Note 77.2 by GR8FUL::WHITE "Without love in a dream..." >>>
>                           -< SCMS Copy Protection >-
>
>Re:                        <<< Note 77.1 by WELCOM::ANDY >>>
>
>>    How much does the copy-prevention stuff actually restrict DAT?
>>    I had heard that if you mastered on a non-"profe$$ional" deck,
>>    that you could only make digital copies directly from the master,
>>    never from the copies.  That is much more restrictive than necessary
>>    to safeguard the revenues of the record companies.  I am also not
>>    sure if this information is accurate.
>>
>	I have heard rumours of a demonstration where a circuit made
>	with about $15 worth of Radio Shack parts that intercepts and
>	negates the control bits so that second generation digital
>	copies can be made.

I have heard this as well.  I would imagine the black boxes that will be
inevitably produced to perform the function Bob mentions will take on the same
status as those black-market cable descramblers you see advertised in the NY
Times classified and many video magazines.  I think the record companies are
banking on the fact that the vast majority of consumers will not understand the
system well enough to know what to do to circumvent it.  Of course we computer
people are not your "average consumer".

adam_who_is_waiting_for_writable_CD's_to_come_down_in_price

    Will a pro deck remove the SCCS from its digital output,
    or do you have to master on the pro deck?
    
    I also heard that some consumer decks can be modified rather easily.
    I don't have any particulars, but since I am in the market for a
    deck, ability to do that is somewhere between "highly desirable"
    and "mandatory".
    
    This is all very silly.  They put this stuff in to allegedly prevent
    piracy, but who would pay $10/tape to make a digital copy of a CD
    that probably only costs $10-$12 anyway???  Anyway, you don't need
    SCCS to prevent digital copying of CDs, since the consumer decks
    can't record 44.1 anyway.

The solution...

SCMS doesn't kick in when you output yer signal through the Analog out.

So, when making dubs to another digital deck, output through analog then input
through analog, and viola! problem solved.

I beleive that the Audio Magazine issue which had the cover article on the Sony
DAT walkman did successive dubs through AD converters.  Don't quote me on this,
but I beleive that even after 50 generations, they failed to detect any
fidelity loss...

Fog

Ger, I think yer mis-interpreting those graphs...

Anybody have the article handy?

Fog

    Also...graphs ain't ears!
    
    	- Prob
    

    I haven't read the article, but why should that stop me from giving my
    opinion?
    
    Here 'tis:
    
    A tape made by doing DAT -> D/A -> DAT -> A/D -> [to 50th gen] will not
    have the SCMS bit set and will sound better than a 1st generation
    cassette -> cassette copy.
    
    >Maybe there's something wrong with my logic, but if there were no
    >fidelity loss copying from the analog outs, then wouldn't those outputs 
    >would be copy protected as well?
    
    Because the SCMS bit is not part of the music information, it's passed
    separately, or not passed at all when using analog outputs.  An early
    copy protection scheme proposed a sharp 15(?)kHz notch filter which would
    have affected the music, but that approach was abandoned because of
    that very problem.
    
    I've never played around with DAT, but the above is my impression based
    on what I've read.
    
    Jamie

>    That should be DAT -> D/A -> A/D -> DAT -> D/A -> A/D -> DAT ... etc -> 
>    for 50 generations. You always record digitally onto DAT, never analog.

Er, I knew that!  :^)

>    50 generations of D/A-A/D conversions will sound better than a 1st
>    gen analog copy of an analog master? Convince me.

    OK, bring over two DAT decks and a case of beer!  :^)  I'll try:

    A digital master sounds better than an analog master, agreed?  Why
    should the D/A -> A/D conversion degrade the sound?  Just because it's
    analog doesn't mean it's bad sound, it's only analog recording that
    causes problems.  I'd bet that a 50th gen DAT made as above would still
    sound better than an analog cassette master.
      
    >In any case, what's the use of spending large amounts of money on DAT 
>    equipment to get a copy that comparable to an analog master? I can
>    already do that with analog equipment. My only reason for going digital 
>    would be to have pure digital-to-digital copies.
    
    I'm (obviously) no A/D converter expert, so I think I'll bow out of
    this discussion while I'm not too far behind.
    
    Jamie

re: -.1  by Jamie

>  A digital master sounds better than an analog master, agreed?

	I disagree.  As I understand it, a DAT master will not necessarily 	
	sound better than an analog master.  It all depends on the mics,
	how the mics are aimed if using shotguns, etc.   Just because a 
	master is made with DAT doesn't mean it's gonna sound awesome, right ?

	If you're talking about recording the same show using the same 
	mics, and split the signal so that 1 feed goes to a DAT deck 
	and another to the analog deck, then yes, the DAT will sound better.  
	From what I've found, a  major difference is that you get no added 
	hiss on a DAT master, whereas you get hiss added, even if encoding  
	with Dolby, on the analog master.    

	Am I way off here ?

	Ken

�There's the factor of having to go through all that extra electronic
�     circuitry. Maybe I'm wrong, but shouldn't there be some fidelity loss 
�     when it does that?

Theoretically, it should be possible to go from digital to analog and back to
digital with no discernible degradation.  Degradation occurs converting between 
sound and electricity (microphones and loudspeakers), converting between 
electricity and magnetic storage (playing back and recording) and high gain 
amplification (microphone or tape head to audio signal).  Note that with digital 
recording, it is possible to �regenerate� the signal.  This means that when  
tape noise or thermal noise is picked up while playing back (which it 
always is) in the digital process, the signal can actually be recreated at
audio signal levels �without� the tape and thermal noise.  Thus, DAT eliminates
two of three major noise sources.  When going from
D/A->A/D, no intrinsically noise-inducing mechanisms need be involved.  With 
the proper set up (not much more than a good pair of cables) there should be 
no degradation.

All this is theoretical.

Bill
     

	You're both right! 

	Its a desert topping AND a floor wax!!!

	Har har.... I think both sides here have valid points.  Doing
	a digital to digital dub will ensure a perfect copy of the master,
	no loss at any generational level.  However, I'd think that the 
	basic performance of even todays relatively early-generation DAT
	decks (here I mean "generation" as in "how long DAT decks have been
	around, and improved upon) would be far better then top-of-the-line 
	cassette decks in the areas of wow&flutter (none vs. around .005? %), 
	S/N ratio (around or better than 90 db, vs. around 78 db with Dolby C)
	etc.  And, you get this dynamic range without worrying about Dolby 
	encode/decode tracking errors (in the range of 1-2 db!).

	Of course, you do have to "worry" about the signal going through
	successive A/D and D/A stages - but I think any distortions added
	by this would be insignificant compared to mic placement, audience
	noise, hall acoustic screwups, etc (in the case of aud. taping).
	And even for soundboard taping, I still think DAT analog dubbing 
	would not detract much, given the nature of the source material :
	"electric rock", with all its built in distortions and sound
	processing going on.  I mean, if you taped a solo acoustic
	grand piano in perfectly empty hall (or recording studio), and
	compared analog to digital dubs after 50 generations, then I'm sure
	the 50th analog copy would sound different from the digital copy.
	
>    >Why should the D/A -> A/D conversion degrade the sound?  
>     There's the factor of having to go through all that extra electronic
>     circuitry. Maybe I'm wrong, but shouldn't there be some fidelity loss 
>     when it does that?
     
	yes, there would (must) be - but is it significant/audible compared
	to the source material?

	BTW, the earlier and abandoned copy-protection scheme involved
	notching out a very narrow slice (like 1 or 2 Hz wide, and many dB
	deep) of the audio, somewhere in the 2-4K range I forget where.
	It was supposed to be inaudible, falling between two adjacent
	piano notes, but people quickly came up with various compositions
	where the 2nd or whatever harmonic fell right in the notch and the
	copy protection circuit was clearly audible, screwing up the sound.

	So "They" devised the digital scheme.

	Josh

    I did mean that digital beats analog casette when all other parameters
    are equal for both cases.
    
    >In any case, my personal thought on all this is that dubbing DAT tapes 
    >using the analog in/outs completely defeats the purpose of digital 
    >recording. Period.
    
    But do you agree that this method still beats analog cassette recording
    by a mile?  Also, don't forget that you can still make an infinite
    number of 1st gen straight digital copies, it's only the 2nd gens that
    are effected by SCMS.  Would this method be an aceeptable comprimise
    until you could figure out how to disable SCMS?  Unless you get pro
    equipment (big $), this problem is going to be around for a long time.
    
    I wish we had access to all these toys, I'd love to do some
    experiments.  I bet that I couldn't hear the difference between a 50th
    gen straight digital DAT and one made through analog input/outputs. 
    Can you pass the digital acid test?
    
    Jamie
     

re:   <<< Note 77.18 by BARFLY::BELKIN "the slow one now will later be fast" >>>

>	Its a desert topping AND a floor wax!!!

;-);-)

Tastes great!!!!!!!!  And look at that shine!!!!!   ;-)

	
	Well the problem of SCMS in terms of Dead tape trasing hadn't 
	occurred to me before - maybe because I had previosuly 
	considered DAT to a ways in the future...
	
	I agree with Gerry.  Not being able to trade digital-digital 
	copies defeats the purpose of DAT.  Why bother?  Or the 
	corollary is that one needs to get a pro deck, which means big 
	$, which means not many will be around.
	
	A question occurs to me - does the SCMS work all the time - or 
	is it only triggered by copyrighted material?  That is, do the 
	home DAT recorders include the SCMS "bit" in every digital 
	recording - or is it triggered by some information in the 
	material being recorded?  This I don't know...
	
	As for digital audio being theoretically perfect, as explained 
	by Bill (SHKDWN::)Taylor, that's true.  But digital audio is not 
	theoretical.
	
	In fact, there was a paper published recently at an Audio 
	Engineering Society meeting by a major guru in digital audio 
	(Ph.D. engineer type working for Sony) that had just now found 
	variations in transfer function of a digital level control with 
	setting.  That is, a digital volume control, considered to be 
	the simplest of digital signal processing functions, has only 
	recently been shown to distort the signal as function of volume! 
	
	And this was something that Doug Sax, head honcho at Sheffield 
	Labs, has been saying for years!
	
	The problems in doing A/D and D/A conversions are many. 
	Linearity of converters is one.  Good multi-bit A/D and D/A
	converters are *very* expensive.  There is some new interest in 
	the Single Bit/MASH/Bitstream technologies allowing a better 
	quality of D/A conversion through the pulse width modulation of 
	a single pulse stream than the traditional multi-bit D/A 
	converters.  However, in both cases, clock jitter in the 
	*picoseconds* can cause audible effects!
	
	Another problem to many is the rather finite quantitization of 
	present digital audio technology.  Is 16 bits, i.e. 65,536
	steps, sufficient to adequately resolve a signal varying over
	several volts?  And what about precision in doing arithmetic in 
	the digital signal processing?  How many bits of precision are 
	needed to not introduce audible errors?  20? 24? 32? 64?
	
	Another problem for many is that the sampling frequency is too 
	low.  The question being is 44,100 samples per second adequate
	to recontruct the audio signal without the anti-alias (recording
	input) and anti-imaging (output) filters being so extreme that
	they in turn introduce artifacts? 
	
	And there are just plain considerations around the introduction 
	of noise and distortion in the analog processing curcuits.
	
	So is digital audio perfect?  No!  Is is very good?  Yes!
	
	Bob_techno_weenie
	

	
>	I agree with Gerry.  Not being able to trade digital-digital 
>	copies defeats the purpose of DAT.  Why bother?  Or the 

And I still disagree with Gerry. If converting the digital signal to analog
before converting the signal back onto another DAT _doesn't_ degrade the sound 
in an audible to the human ears, even after only _20_ generations, then DAT
still has a damned worthwile purpose.

Fog_who_still_remebers_reading_somewhere_that_there_was_no_audible_loss_in_
fidelity_after_50_passes_through_A/D_converters,_but_can't_for_the_life_of_him_
remeber_where.

    re .24
    
    I'm fairly positive that SCMS does apply to audience/sb recordings. 
    You can probably find the definitive answer in the Audio conference. 
    Digital recording from CDs is already prohibited because consumer DATs
    don't record at 44.1 kHz, right?  
    
    Jamie

	
	Well, Ger, a few notes ago you said (approximately) "all the DAT 
	tapers you knew had pro equipment so they couldn't answer the SCSM
	question"......
	
	So..... you owe it to the Holy Cult of Dead Tapedom to GET A PRO
	DAT DECK!!! Don't be the weak link in the chain, man!!!!
	
	many, many ;-) !!
	
		Josh

>    to dub onto). Many, if not most, of these folks wouldn't even consider 
>    trading if there wasn't a pure D to D transfer.
    
Ger, YOU'VE said this, but haven't produced any evidence that anybody else has;
or why.  I wanna see evidence, offline if'n ya wish. And I'll do my best to
find evidence for my opinion...

Who knows, maybe dubbing through analog outs as opposed to digital outs sounds
better (because error checking happens in analog-out mode, and maybe not in
digital-out mode)?

Fog

    All the information I've read about the SCMS decks indicates that one
    can make any number of 1st generation copyies of a "digital source".  I
    interpret this to mean that *any* digital source is affected by SCMS. 
    Including live recordings that aren't subject to copywrite or royalty
    issues. :-(
    
    Remember, this scheme was implemented because actually encoding
    something in the audio signal of copywritten material turned out to be
    audible.
    
    re: Pro decks...Digital to Digital only
    
    The possibilities for elitism are astounding.  Just think of the
    negotiations necessary to perform a tape trade under these
    circumstances.  Not my idea of fun.
    
    	- Dave
    

    I'd heard that at least one consumer deck had an unmarked switch inside.
    Throw the switch and no more SCMS!  I don't know which deck this is tho.
    
    A box to spare us all this should be really easy to build.
    Does anyone have a copy of the DAT specifications, or know where to
    find them?

    re: .23 by Bob White
    
    > However, in both cases, clock jitter in the *picoseconds* can cause
    > audible effects!
    
    I *hate* when that happens! :-) :-) :-)
    
    My point of view -- like Dave Levy said, the elitism aspect of "I won't
    play with you unless you have a sandbox as good as mine" is a real turn
    off to me.  Take all the fun out of it.  I'll let the elitists spend
    their money and have their "fun".  I'll make due with "shitty old"
    analog tapes, until I run into a real big pile of money that I don't
    know what to do with...and that will be long after I find the $10K+
    necessary to purchase a brand spanking new Harley!
    
    GerG, I love reading what you write.  I'm sorry to see you getting
    bummed out in this topic.
    
    tms

 Thanks, I sure have learned a lot from your discussions.

   john

	Well, if anyone has a Sony DAT deck I'd be MORE than happy to
	open it up and look around for a Secrit Anti-SCMS Switch!!!

		Josh

    One of the audio magazines that actually listens to components rather
    than just measuring them (I think it was The Absolute Sound)
    experimented with a DAT deck several months ago. Their conclusion was
    that a 5th generation D-to-D copy was clearly distinguishable from a
    master. They had no idea why.
    
    I have an idea why. Given that a DAT dub is made in real time with
    little (or no?) opportunity for error correction at very high media
    density, some fraction of the bits on a copy are going to be different
    from the bits on the original.
    
    I would advise anyone who is thinking about investing in DAT with the
    intention of making n-generation digital dubs to find a store that will
    let you try out 20 or so generations of a 3-minute musical fragment and
    compare the 20th generation to the master (using reference-quality
    amplifiers and speakers). I have no idea what the results would be.
    
    I would also advise anyone who is thinking about archiving their analog
    tapes to DAT not to discard their analog masters. A DAT copy may not
    turn out to be as permanent as one might hope. Tape fades, especially
    tape recorded at a very high density.
    
    John

                       <<< Note 77.41 by DECWET::HAMBY >>>
                       -< And you thought I was gone... >-
>    John


I did....where have you been?
just a wondering.

same note same name same file....
just a lapse in time
bob

Ger,

I still see no evidence that d-d/a-ad/d dubbing causes _discernable_, _audible_
differences in the quality of the sound after successive dubs. Yes,
converters degrade the signals passed through them.  But how much? How does the
quality of the converters fit in?  How many generations on deck X can you dub
like this without discernable loss of fidelity and sound quality? The
characteristics of converters you posted are very interesting, but don't really
prove that using them is "bad".

Now, I see in -.2 that straight D-D dubbing isn't all its cracked up to be.
Maybe my "out there" statement a bunch of replies back _is_ possible 
(suggesting that dubs through converters could preserve the sound better than
straight digital dubs)?

Fog_..._..._...

    A D-to-D copy has whatever errors are introduced in the tape read/write
    process. A D-to-A-to-D has all of the errors of the D-to-D copy, plus
    whatever errors are introduced by a D-A conversion and an A-D
    conversion, plus whatever distortion is introduced by the analog
    circuitry of each deck.
    
    My point was just to claim that a D-to-D copy may not be perfect, not
    that a D-to-D copy might be inferior to a D-to-A-to-D copy.
    
    John

    More bad news: even using pro decks to generate n digital copies, the
    signal must still be converted to analog before you can hear it. 
    Scientists are working on a direct digital interface to the human ear,
    but they're having a hard time coming up with test subjects.
    
    
    Jamie

I see a serious party opportunity here.

Let's get REB and Tim Dalton to show up somewhere with their DATs and
try out the various scenarios!  

Bob White could bring his super EQ unit to monitor the systems mechanically.

Lots of us could bring ears to monitor the systems biologically.

Of course, no intoxicants would be allowed at
this party since that might interefere with the ability of the participants to
tell what sounds best.

I predict that the results of the party would most likely cause *more*
disagreement than we have already. :^)

	- Analogue Dave

RE:   <<< Note 77.47 by SA1794::GLADUG "negativity don't pull ya through" >>>

Ger, I'm bummed out too. I just wanna stress that I'm not arguing with you for
arguments sake, nor am I trying to discredit your knowledge of this new
technology.  I guess I just got pissed at your taking certain positions which I
don't think are fair to my replies, regardless of how wrong they may be. I feel
forced to respond when in an attempt to learn more and suggest possibilities, I
am confronted with replies which are not constructive, only posturing.

I appreciate your thoughts as much as the next guy, and am as eager to learn
more about DAT as you are, but consider replies like the one below and how you
would react if you were on the receiving end. Would you be a little defensive?
Would you question the reasons why the author of such a reply reacted so
strongly? Ger, you did ask me offline if I wanted you to delete .8. I said no
because I felt you and I could deal maturely with debate on the subject. I
guess I should have said yes.


Note 77.8:

    I wouldn't even remotely consider this a solution and would absolutely 
    *not* trade with people who dub this way - and you're not going to find 
    many serious traders who will.
    

Agains, Sorry.

Fog

Absolutely...we need a party...a DeadShow...a KnotShow...

From a semi-disinterested party:

	  There is nothing wrong with strong opinions.  However, if expressed
	  strongly, the author ought to be prepared for strong responses.

	  IMHO making sweeping statements and taking stances like "I will
	  never...", "No one who is serious about xxx thinks...", etc. will
	  cause people to feel alienated and perhaps angry.  I think that there
	  are more sensitive ways to express opinions.

	  No one likes to feel left out of something.  Some of the stuff in
	  here made *me* feel like I was going to be sh*t out of luck for 
	  getting some really nice material if I wasn't able to spend $3K for
	  a couple of pro DAT decks.  That's where my "elitist" comment came
	  from.

Please!  Can we have fun with this?  If not, it probably doesn't belong in
GRATEFUL.

These are tough times in the real world and the Digital world.  Lots of 
uncertainty.  Perhaps we can give each other a little more space than usual
while we all struggle through these times.

Ger - I invite you to please keep playing in this field.  Many of us can benefit
from the research you've done and the information you share.   However, some
of your statements *do* seem to be worded so as to invite controversy and 
argument.

Fog - Although I share some of your sentiments and feelings when I read these
postings, I'm not sure that we should continue the personal discussion in this 
medium.

Note - I'm not trying to be a censor...more of a mediator...ummm...negotiator...
ummm...I got it!  A MODERATOR!  Gee...what a great title for someone who
helps keep discussions on track.  Glad I thought of it! :^)

	- Dave

RE:         <<< Note 77.50 by NECSC::LEVY "Across the lazy river" >>>
                               -< Relax please >-

o.k, Prob, I'll relax.  

fwiw, Both Ger and I agree that given the given that you are restrained to SCMS
encoding, dubbing through converters would be preferable to encoding an
SCMS-protected copy onto another digital machine..  (did i get that right Ger?)

fog

    chill out guys ! when after all is said and done that tape will get
    played thru some cheap boombox and listened to by a pair of beatup
    headphones that are held together by masking tape and it sounds just
    fine to me !
    
    Chris_who_listens_to_most_of_his_tapes_this_way

    
    Am I the only one in here who doesn't know what the heck any of them
    are talking about?!?!?!?!??!?!?  Someone *please* tell me I aint gonna
    have to understand this to get new tapes!  ;-)
    
    

    ref -1
    
                          no
    
    
    
    rich

    relax Phyllis!  i'll pretend to understand it all so that they make me
    tapes, and then i'll dub for you! :^) :^) :^)
    
    		da ve_who_sort_of_understands_but_not_completely :^)

    
    :-)  thanks, da ve.  Phew!  for a minute there.. 
    
    ;-)
    
    

RE:          <<< Note 77.53 by TERAPN::PHYLLIS "Wake, now discover.." >>>

    
>    Am I the only one in here who doesn't know what the heck any of them
>    are talking about?!?!?!?!??!?!?  Someone *please* tell me I aint gonna
>    have to understand this to get new tapes!  ;-)
 
	Well consider this Phyllis .... has it stopped you in the past?  ;^)  
    
:-)

uuuuuuuuuuuuuuuuuuooooooooooooooooooo ggiiirrrrrrrlllllll  you had better put
smiley faces on that reply.


    john

Gees, John .. clean your glasses ... I did!!!  :-) ;^) :-)

    
    Oh excuuuuuuuuuuuuuuuuuuuuuuuuuse me, Miss Technology!  At least I have
    no trouble getting the protection right on my directories so MY friends
    can copy cool stuff from ME!  
    
    :-)
    
    

I'd like to propose that nobody trade with Phyllis, unless she passes the
TAPE TECHNOLOGY THEORY AND PRACTICE EXAM ....

All of the information in here fair game....

Start studying......


 			:-)  * 5,000

    ...and these days it's really important to get your protection right... :-)
    
    tim
    

  -1
   HAH

    
    I'm just glad they keep it all in one place - errr - note.
    N U 
    
    carol

    Neato - I just found a printout from the original GRATEFUL of one of
    Doug Moog's topics titled "TAPING - fact & myth."  In it he warns:
    
         I'd just like to add a caution: this is another one of my
         controversial notes. Everyone has an opinion. So let's see if
         we can just throw out our views for general consideration
         with the knowledge that someone will attempt to shoot them
         down mercilessly.  OK? Go easy on the capital letters and
         exclamation points, okay? For example:
         
         Your method of storing tapes could lead to degradation.
         
         is much more effective than:
         
         YOUR method of "storing" tapes will lead to DEGRADATION!!!!!!
         
         
    It's interesting that the discussion stayed calmer in the war note than
    here.  Not surprising really, the war will eventually end, but DAT
    (should) last forever!
    
    Jamie

re: .65

>but DAT (should) last forever!

I'll argue that point.  With DAT you have some of the same problems that
you have with any tape:

	- Dragging a strip of plastic across a metal head seems to cause wear 
		and degredation of the magnetic coating.

	- Mechanical parts inside of the cassette assembly can wear out.

	- Storage in imperfect conditions (I don't know anyone who stores
		tapes in an environmentally controlled area) can cause 
		degredation of the magnetic coating even if you never play the
		tape.

I'd still guess that recordable CD (when/if it happens) would last longer than
DAT.

	- Prob

    You can't blame someone who went out and spent the big $'s for the DAT
    deck for wanting to trade D-D. They spent the money for improved
    quality, and they want to improve the quality of their tape collection.
    
    ABout the "eliteness" of it all,... that will change big time within
    a year or two, as the competition for the DAT consumer market heats
    up, and everybody startrs dropping their (ridiculous) prices for DAT
    decks.
    
    Fog,.. it is a *fact* that conversion in any form (d=>a or a=>d, and
    even a=> a) incurs distortion. Whether that distortion is actually
    auidible after x generations depends on the quality of the converters,
    and the sensitivity of the listener's ears. The latter being a
    completely subjective matter, why even question it? There are those out
    there who will claim thay can hear above 20Khz anyways,. :-) :-)
    
    It is in theory possible for d=>d conversion to take place without
    distortion. I'm sure that some of the better DAT decks can approach
    this, but others probably aren't even close.
    
    So what are we going to argue over next? Hell,.. you know we have these
    damned analog guitars organs and drums up there on stage. Personally
    I don't know why they don't just replace the boys with a few Pcs and
    get it over with...
    
    							/
    

>    I don't know why they don't just replace the boys with a few Pcs and
>    get it over with...
    
HA!  :^)

Then what would they replace US with?

Need something to replace our analog acoustically-imperfect ears ;^)

- Dave

re < Note 77.70 by ISLNDS::CLARK "words � spoken and thoughts unclear" >

>Then what would they replace US with?

   Pro 350's.  It was already tried - remember the bumper sticker:

	"DEADHEADS - THE PROFESSIONAL AUDIENCE"	

   						:^)

    
    
    	From todays   5-16-91 Wall Street Journal:
    
    SONY Announces new mini CD player/recorder
    
    Basic Info:
    
    2.5" diameter CD's
    Available 1992
    Recorder same size as "typical" walkman
    Anti "Jitter" mechnism for joggers and recording live
    Not as high qual as DAT or standard CD's, but SONY says pretty close
    CD - 74 minute length 
    Blank CD Cost: Same as standard HiFi audio tape
    Won't play in standard CD players
    No Cost info given, but "affordable" SONY says
    Currently in Prototype form
    
    Article also mentioned Phyllips new Digital Cassette deck and
    Radio Shacks recordable CD and the fact that Royolties (or money
    grubbing record companies IMHO) keep getting in the way of Digital 
    technology, esp. in USA.
    
    
    Regards,
    
    Randy Switts
    Atlanta ACT
    Imaging Solutions

re:< Note 77.72 by SAHQ::SWITTS "Its Spring in Atlanta !" >
>                     -< SONY Announces Recordable 2.5" CD >-

>    SONY Announces new mini CD player/recorder
>    
>    Basic Info:
>    
>    2.5" diameter CD's

Why make them in a new format?  I guess Sony wants to monopolize the "mini-CD"
market like it's tried to do so many other times.

Thompson from Germany already has a writable CD player with standard size CD's.

>    Not as high qual as DAT or standard CD's, but SONY says pretty close

One reason why they should stick with the standard size.  Perhaps the fact that
they're putting 74 minutes of music on a CD 1/4 the size of regular ones means
they're sacrificing sound quality, since you can't cram as many bits in one
fourth the surface area.

>    Blank CD Cost: Same as standard HiFi audio tape

From a manufacturing standpoint, I believe this.  However, I doubt this will be
reality due to inflated prices forced by the music industry.

Anyone who believes a CD costs the publishing company $10 is wrong (IMO).

>    Won't play in standard CD players

Too bad.

>    Article also mentioned Phyllips new Digital Cassette deck and

I've heard about this.  I think this is a big gamble by Philips since DAT is
already pretty popular and another format thrown into the fire will just make
things more chaotic for the industry.  I think if S-DAT (what Philips has) came
out before R-DAT (what is currently on the market as "DAT"), S-DAT would have
taken off.   I think it's a preferable format simply because the cassettes are
the same as conventional Compact Cassettes.  The Stationary format also is
lighter, smaller, costs less, and has less moving parts than the Rotary format. 
Remember, an R-DAT deck is analogous to a VCR, while an S-DAT deck is analogous
to a regular tape deck.

>    Radio Shacks recordable CD and the fact that Royolties (or money
>    grubbing record companies IMHO) keep getting in the way of Digital 
>    technology, esp. in USA.

So true.    

    Does anyone know if there is such a thing as a double-decker with one
    DAT tape and one conventional cassette.  I'm thinking of upward
    compatibility for people with large cassette collections.
    
    -Dermot

>    Blank CD Cost: Same as standard HiFi audio tape
    
     FWIW - Standard 90 minute *HIFI* audio cassettes cost $15-$20 apiece.
    
     - Gerry

Re:                      <<< Note 77.75 by SA1794::GLADUG >>>

>>    Blank CD Cost: Same as standard HiFi audio tape
    
>     FWIW - Standard 90 minute *HIFI* audio cassettes cost $15-$20 apiece.

	Uh, Gerry, can you say more about this?  I'm confused...

	Are you speaking of DAT tapes?  If so prices have some down in
	the past several months.  120 minute DAT tapes from Maxell and
	TDK now cost about $10 by mail order....

	As for RDAT versus SDAT - I think SDAT has an excellent chance of
	catching on - strictly based on the facts that:

		RDAT decks at $700-$800 are way too expensive for the
		 mass market
		Same shape tape as the ubiquitous "Compact Cassette" we
	 	 all know and love
		Tape stock will be much cheaper

	But the whole key to SDAT success is going to be the availability
	of software.  If the consumer can't go buy the latest Whitney
	Houston or Def Leppard tape for about the same price as today's
	analog cassettes, then the game is over, IMHO.

	Bob_opinionated

re:        <<< Note 77.76 by GR8FUL::WHITE "Without love in a dream..." >>>
   
     >>>Blank CD Cost: Same as standard HiFi audio tape
      >>FWIW - Standard 90 minute *HIFI* audio cassettes cost $15-$20 apiece.
       >Uh, Gerry, can you say more about this?  I'm confused...
    
       Like Maxell Vertex Metal tapes and TDK MA-XG metals (I think it's
       the MA-XG). They go for $15-$20 apiece. Extremely excellent quality
       but rather pricey. I would consider them HIFI tapes. The rest I
       would consider to be just "audio" tapes. And, yes, the are that
       expensive. 
    
       I have heard tell that comparisons made with these tapes on the new 
       dolby S decks "claim" to be "audibly" close to DAT. Of course, a dolby S 
       deck costs more than a DAT and the HIFI tapes are far more expensive 
       than DAT tapes. Not to mention DAT will measurably blow away the dolby 
       S deck. 
    
       The tapes are used by serious recordists, HIFI buffs and Dragon owners 
       who are not into DAT. I wouldn't use them for anything but masters, 
       copies of masters made on Vertex's or copies of CD's and DATs.
    
       - Ger_who_doesn't_really_want_to_get_into_an_audio_discussion_again
         so_we'll_leave_it_at_thet.

    In case it isn't clear, the "HIFI" tapes I'm talking about are analog.
    
    - Gerry

    I'm curious about the technology of DAT tapes vs. writeable CD's.  It
    would appear that a CD, by virtue of it's simpler construction, would
    be less likely to be lost due to decay, abuse, neglect (except for
    surrogate-frisbee use) and such, than the DAT tape.  I mean, it stands
    to reason that the DAT tape has more moving parts (i.e. > 0), and a
    more fragile media physically than the CD.
    
    Has anybody looked at the relative long-term vitality of these two
    media?  I kinda like the sturdiness of the CD.  If it were writeable, I
    don't know why DAT would be better.
    
    tim
    

    I remember reading somewhere that the verdict on longevity of CD's is 
    still out. Light may cause decay of information. 

re .79

>    I'm curious about the technology of DAT tapes vs. writeable CD's.  It
>    would appear that a CD, by virtue of it's simpler construction, would
>    be less likely to be lost due to decay, abuse, neglect (except for
>    surrogate-frisbee use) and such, than the DAT tape.  I mean, it stands
>    to reason that the DAT tape has more moving parts (i.e. > 0), and a
>    more fragile media physically than the CD.

Absolutely! It also means that the players & recorders should be cheaper & more
reliable because there are fewer moving parts. I would dearly love a DAT player 
but the present cost is prohibitive, I can't really see them reducing in price 
an awful lot more. CD players can be had very cheaply nowadays & I would expect 
the cost of a recording machine to be no more than 50% higher, even if it was 
100% higher than existing CD players it would be cheaper then a DAT. I believe 
that Sony's target price is about $300.

Nigel

    I would guess that if DAT continues to be popular and isn't pre-empted
    by yet-another-new-technology, that the decks could get pretty cheap.
    The first VCR's and the first CD players were up around a grand way
    back when, so there's reason to expect that trend to prevail.  The
    problem I would see is that cheaper manufacturing techniques on a
    complex device like a DAT might provide a far less reliable product.
    VCR's are internally complex, and the cheap ones live up to their
    price.
    
    tim
    

Re: tim

That is was I hope happens.  I bought my CD player before the mad craze hit.
I paid $230, on sale from $280, for my disc player.  Today, a comparable
player can be had for $99...

this was in late '85 or very early '86

    *Consumer* DAT prices will drop - they're already 50% of what they were
    2 years ago. However Pro DAT prices may not drop quickly if at all. As
    an example, some analog pro portables are still about the same price they
    were over a decade ago. Because of SCMS, you'll need at least one pro deck 
    to do any D-to-D dubbing. Hopefully the pro deck prices will drop also,
    but most likely due to some models becoming obsolete (eg - SV250).
    
    - Gerry

    regarding medium longevity, I would agree that the CD is mopre durable.
    However, the means to record on a CD are not so trivial. The argument
    	that a player (strictly a player,. not a recorder) for CDs must
    be cheaper because of less moving parts seesm to hold water. The
    recorders would also be chepaer by the same argument if the mechanism
    of doing the record were comparable,.. but they are not. The basic
    recording mechanism for magnetic tape is well understood thanks to
    the experience the industry has with analog tape,.. but the industry,
    and the consumer have no experience recording on CD,.. which is new
    technology,. which will probably mean it wil lbe some time before
    cheap *reliabe* CD recording machines are available.
    
    What does it all mean?
    
    Decode this for the answer...
    
    
    00100010
    
    00100100
    
    
    0100100111
    
    1110101010010001010001010101010101010100101010101011001
    
    							/
    

    DAT tape decks will never drop below a certain level so if you are
    one of those people who think if you just wait a few years you can
    buy a DAT deck for $200 forget it and start saving.... 
    
    DAT decks are very similar in nature to HiFi VCR decks. If you
    look at what has happened over time to the prices of standard VCR decks
    they started at $500 and are now $250, thats not bad.  
    
    If you look at a decent HiFi deck they were around $1100, they are now
    around $600-700, and thats about as low as they will probably get
    because they cost so much more to make.  I believe the same will
    hold true for DAT decks.
    
    Keep in mind, DAT has been around for a long time, so it has already
    gone through much of the price reduction that VCRs have gone through.
    (Every where but in US it has been around for a while, money grubbing
    record companies and lobbied congressmen kept it out of the US)
    
    Anyway, DAT will probably not get much cheaper because it has already
    gone through much of its life cylce outside the US, plus they are
    expensive to make because of the flying erase heads and other 
    "hard to manufacture" parts.
    
    RS>
    

    >If you look at a decent HiFi deck they were around $1100, they are now
    >around $600-700, and thats about as low as they will probably get
    
Hey Randy, how are ya!!  I've been thinking about getting a HiFi VCR and I 
just saw an ad for a local store, Lechmere, which has HiFi VCRs on sale for 
under $500, sounds like either it might be a good deal or one of those "you 
get what you pay for" deals.  I can't remember which brand it was, but I know 
it was of the "big names."  I kinda bummed to hear that the technology is so 
expensive, time to start saving I guess!

Scott

    
	Yet again, from the WELL. This is a deep detailed book
    about DAT technology. Very technical.
    
    ----------------------------------------------------------------
      
   Principles Of Digital Audio
   Pohlmann
   SAMS books
   ISBN 0-672-22634-0
   
   
   800-428-SAMS for the dealer near you that carries SAMS books.
   

    ...from the AUDIO notesfile.
    
               <<< VAXWRK::$1$DUS6:[NOTES$LIBRARY]AUDIO.NOTE;1 >>>
                          -< The Emperor's New Audio >-
================================================================================
Note 3072.10            DAT vs Analog.  Which is better?                10 of 11
PSW::WINALSKI "Careful with that VAX, Eugene"        29 lines  17-JUL-1991 23:45
--------------------------------------------------------------------------------
RE: .9

SCMS works as follows:

For analog input, the resulting DAT recording is protected with SCMS code 11,
which allows it to be dubbed one more generation.  Dubs of the dubs cannot be
made.

For digital input, the rules are the same regardless of sampling rate.
If the digital input signal transmits the SCMS subcode, action depends on the
value of that subcode:

	input SCMS of 00:  output SCMS is also 00, allowing unlimited dubbing
	input SCMS of 10:  recording is prohibited
	input SCMS of 11:  output SCMS is 10.  The resulting DAT cannot itself
				be dubbed

If the digital input signal does not transmit the SCMS subcode, action depends
on the SPDIF "protection" bit in the header block of the signal.  If the
"protection" bit is clear, the resulting SCMS code is 00, allowing unlimited
dubbing.  If the "protection" bit is set (as it is for nearly all commercial
CDs), the resulting SCMS code is 11, allowing one more generation of dubbing
for the DAT.

All the dubbing being discussed above is digital dubbing, of course.  There is
no limit on analog dubbing, but you risk signal degradation (very minimal
in practice, if you have decent equipment).

--PSW
    

        first, let it be known that i do not stand to profit from this
    announcement in any way shape or form...  it is posted as a public
    service to people in this file who may be looking for a good deal on 
    a new DAT player...  
    
    	fwiw, i know the gent involved and know him to be someone of
    integrity who is not out to take anyone to the cleaners...  what we
    have here is a legitimate opportunity for folks who want some nice new
    equipment at a real discount...  in order to get a cheap price for his
    own decks, he picked up a few to get a huge discount...  please deal
    direct with him as i am NOT a party to any sales, merely a messenger...
    
    thank you...			da ve
    
    ps. if mods feel this is in anyway inappropriate for this conference,
    please let me know...  it will be nuked immediately...
    
    
From:	SCOMAN::RAPHAELSON   22-MAR-1993 13:13:46.43
To:	DWEST
CC:	
Subj:	

I'm currently negotiating to buy the remaining stock of DAT machines from a 
supplier who doesn't want to carry them anymore.  There will probably be 
more machines available than I need for myself, but I'll have to take them 
all to make the deal work. So far, it appears that remaining stock consists 
only of Sony Consumer DAT TDC-3 Portable DATMan recorders. Some will be demo 
units - they sat on a shelf to be examined by customers, but most were never 
plugged in and/or used.  They come with an ac/dc power converter, ni-cad 
pack, pseudo leather case, and a few patch cords.  They have stereo mini 
jacks (1/8") for line/mike input (with 20db mike pad), line out, and heaphone 
out.  There is an optical digital output as well.  Start indexing and 
rewriting, elasped time, section time, level meters, etc. are shown on a blue 
backlit LCD. They are still current line Sony merchandise.

	I bought two earlier in the year to use on a couple of road projects, 
and they've been working great, survived a few falls, airline trips, etc.
They currently retail for about $650, give or take a few bucks. I expect to 
be able to extend them to other people at about $325 @. I'd like to start a
waiting list of people who would be interested in purchasing the extra units
from me, if this deal goes through.  I'll start the list as first reply, 
first option, and notify people asap when I'm sure of final price and dates.
If it happens, I'll need to paid in cash or money order upon delivery, because
I'll have to float this on a credit card for general mail order security r
easons, but I don't want to pay any interest on it.  Please reply via E-Mail 
only, as my intent is to extend my potential good luck to other appreciative 
hard working midiots, audio propellor heads and music mavens, not to tie up 
my DEC office time and resources by opening "DAT R Us".

Jon Raphaelson.....................SCOMAN::Raphaelson.......................
                                                

> There is an optical digital output as well.  

The only other digital I/O on the Sony D3 is through a special 7-pin
connector.  Sony will sell you the special adapter box (to get coaxial and
optical I/O) for an extra $200, so you can record with a D3 via the digital
inputs. 

> They are still current line Sony merchandise.

That's bullsh!t ...  Sony is no longer shipping D3's to the US according to
what I've heard from 2 different sources on DAT-Heads over the last week or
so (why do you think this dealer is so eager to get rid of 'em?!)  

Sony will very shortly introduce the DTC-D7: an even smaller, lighter,
less-power-hungry, portable deck...and rumor has it they'll make play-only
and play-record versions for different prices.

> I bought two earlier in the year to use on a couple of road projects, 
> and they've been working great, survived a few falls, airline trips, etc.

Many people who own D3's have had problems with them ... many gripes on
DAT-heads about the D3 eating tapes, getting jams, batteries dying
(replacements/extras cost $70).  It's not a reliable deck by comparison to
other portables.  I don't recommend that anyone buy a D3 at any price.

- jeff

Thank you for your input Jeff!
JC

    Gee, its hard to let this one lie. I own a D-3, and have had it for
    close to two years. I have had only one set of problems, whcih just
    started. The heads are out of alignment and the deck is on its way to
    Sony for correction.
    
    Sony makes three Digital I/O cables, one is Digital input only, with a 
    coaxial connecter on the other end, one is the supplied fiber optic
    cable, whci does input and output (I have heard of people using this
    cable, plus two D-3's and some tape to dub digitally), and lastly the
    $200 device (which by the way, requires AC power).
    
    This is a good deck to bring to a show, and sit on the end of a Digital
    chain, or to bring to taping parties. It is not a good deck to connect
    directly to mics, since the input is the mini-plugs. 
    
    One important fact to know is that this is a commercial deck, and thus
    it writes SCMS copy protection codes on the tapes it write.
    
    There are lots of things you can do to correct the battery problem,
    most commonly, building an external battery supply - cost $25.00...
    
    If you have questions, mail to me.

    gee, where's Bob White when you need him?  :^)
    
    					da ve

Someone in my group saw one of them new-fangled mini CD player/recorders at
Circuit City in Nashua, over the weekend.  $800-and-something.  He said he
was told that the CDs only hold 60 minutes of music (not 74) ... maybe to
improve the sound quality?  Anyway, it sounded interesting.  Seems like it
would be nice to have in the vehicle ... not quite as bulky etc.

- DC

re: MD

> He said he
>was told that the CDs only hold 60 minutes of music (not 74)

i believe there are 2 sizes available, 60 minutes and 74; clearly not adequate
for live recording; and blanks are outrageously expensive

- rich

Also, data compression is used, I reckon, therefore sacrificing some sound
quality...

Yup, the data is compressed, using either PASC or ATRAC (I forget which one MD 
uses and which one DCC uses). Either way, they throw away the parts of the
spectrum that they think you can't hear.

gary

>Yup, the data is compressed
>they throw away the parts of the
>spectrum that they think you can't hear.

but you don't just lose once; it probably wouldn't be so bad if you just had
a lossy compression, could then do endless generations of lossless digital
copies, and then did decompression just at the analog playback end; but to 
make it imperfect, you go thru the decompression-recompression cycle every
time you make a copy; so the copies are lossy and a 10th gen copy won't sound
the same as a 1st (as it will on DAT, except for read/write errors)

i'd be interested to make a copy of a copy of a copy of a copy...etc... and
see how a 10th gen sounds to the original; i have yet to find a store with
more than one machine, however

also, from what i hear the real-time compression (what you'd use for your own
recording) isn't as good as the ideal compression (what the record companies
use on pre-recorded music)

- rich-not-yet-an-anal-DAT-taper-but-still-endlessly-pondering-the-thought

Yeah, good point about repeated A/D, compress, decompress, D/A, etc cycles.

You would hope that it would deal with this elegantly, but the chances are that
distortion from the A/D and D/A and associated filtering will mess with the
compression.

This is what comes of technical solutions to political (or economic if you
prefer) problems.

gary

I've been informed by my co-worker that he tested the mini-CD player/recorder
thoroughly, and has summarized his findings as follows:


	It sounded real cool.

I hope that this hasn't confused those of you out there who are of a non-
technical nature.

- D "how do I work this?" C

IMBO  [B = biased ;-)]  ...  MiniDisc machines sound about as good as your
average portable CD player.  For the average consumer, this is all (s)he
needs because a portable CD player will be the best sound they ever get out
of their system.  MiniDiscs would be great for the car (get a portable or
pull-out that you could use both in your living room and in your car), but
they're still too damn expensive ($800 for the deck, $15 for the blanks).

At their current prices, they're just a marketing gimmick.  When car CD
decks first came out, they were exhorbitantly priced too... ...here's
hoping that MDs are cheaper (and sound better) in a few years!

8-)

- jeff

re: MiniDisc.

I heard one in Lechmere a few months ago.  I listened to a sampler disk with
about 10 different songs on it, and it sounded very good through headphones. 
The list price of a recording/playback unit is $749, and the play-only is $499.

Technically, the MD system, and DCC as well, employs data "reduction", not
"compression".  The difference is, with compression, you take the full bit
stream at the sampling rate (44.1 KHz?) and compress it using one of a number
of digital data compression algorithms.  With reduction (ala PASC/ATRAC), you
eliminate analog portions of the music signal that the algorithm deems
"insignificant in its contribution to the total musical information" (my own
paraphrasing), then digitizes that.  You can probably compress the resulting
digital bit stream to further reduce the number of bits needed to store the
information, but I don't believe the MD system does that.

For playback, the MD player generates the "reduced" version of the music which
apparently sounds pretty good, but is not the original music.

Making n-generation copies forces multiple D-A-D-A-etc stages, but isn't that
the case of a CD player without digital outputs?  Theoretically, once you
playback the MD bit stream and get the "reduced" music, further re-reduction
should not yield a new bit stream since the music is already reduced.  I don't
think the MD system adds fake information to the music to fill in the "reduced"
parts.  If the MD unit provided digital outputs, you could make exact n-gen
copies of a MD "master".  And if what I said about the stored bits on a MD
being reduced not compressed, no uncompression needs to be done, and the
digital bit stream would be recordable by another digital device of any type. 
I admit I'm not sure if the bits on an MD are compressed or not.  It would seem
that reduction (which is definitely done) plus compression on top of that would
be just too much post-precessing in my opinion.

Sony's ads state the system can record 74 minutes.  There are 60-minute
versions of the 2.5" disk as well.

I'm waiting for a 5.25" disk form factor so no reduction is necessary.  The pit
geometry of a MD is the same as that of a CD, so a 5.25" MD can hold the same
amount of information as a 5.25" CD.  Whether Sony will offer one is up for
debate, since major legal hassles will result.

adam

>If the MD unit provided digital outputs, you could make exact n-gen
>copies of a MD "master".  And if what I said about the stored bits on a MD
>being reduced not compressed, no uncompression needs to be done, and the
>digital bit stream would be recordable by another digital device of any type. 

i was under the impression that the data reduction was done once the data was
already digitized; i think that there is further data loss by going thru
decompression and recompression, because the algorithm isn't perfect to be able
to work in real time; so if these two assumptions are correct (again, i really
don't know for sure), then the problem isn't going thru the A/D-D/A cycle
(which is needed on a consumer DAT deck unless you have an SCMS stripper or
started with a master recorded on a pro deck), the problem is going thru the
compression and decompression repeatedly; i think that there might be digital
i/o on the machines, but it goes thru the compression/decompression chips
instead of making a straight digital copy; you could get around this by only
going thru it once and making straight digital copies, but that would mean
that there wasn't generational loss; as far as consumers go, that would be
good, but as far as the recording industry thinks, that would be bad

>I'm waiting for a 5.25" disk form factor so no reduction is necessary.

i don't think it's a question of whether or not it was necessary; i think the
recording industry thinks it is desirable

- rich

re: lossy dubbing MD->MD

The process flow for recording with MD is:
    analog input signal -> A/D converter -> ATRAC 'reduction' -> write to
    disk.
and playback is:
    disk bitstream -> ATRAC 'inflation' -> D/A converter -> analog output.

Most MD units I've seen have digital inputs and outputs.  They accept and
produce IEC-958 (type 2) formatted signals (CD and consumer-DAT format) on
their digital inputs and outputs.

So if you record digitally from a CD player, you go:
    IEC-958 digital signal from CD -> ATRAC 'reduction' -> write to disk.
and when you play back using the digital outputs, you go:
    disk bitstream -> ATRAC 'inflation' -> IEC-958 digital output.

Unfortunately, no matter what you do, you have to deal with the ATRAC
degradation at each read/write operation.  This is what causes the
generational loss with MD, regardless of the interface you use for dubbing.
The other obstacle to getting lossless dubbing with MDs is that they write
and obey SCMS, which will only allow one digital generation off an analog
or zero off a digital source.  So your generations will be analog-digital-
analog-digital-etc.  as they are with consumer-DAT dubbing of SCMS
protected recordings.  So not only do you have to deal with ATRAC
degradation at each generation, but you add D/A->A/D degredation at every
other generation.  We can't have that now can we!?!!

> I'm waiting for a 5.25" disk form factor so no reduction is necessary.

Hey Adam, wait no longer!  You can get a recordable CD blank for ~$30 and
the recorder for only $4000.

- jeff

PS -- Anyone up for a discussion of jitter-induced bit errors and
interpolation degradation in digital transmission and D/A conversion???
It's the current rage in high-end audio!  ;-)

re .103

Since when is 'data reduction' not compression?

My understanding is that PASC/ATRAC compression occurs in the digital domain, but
you are correct in that they both throw away data that "you wouldn't have heard
anyway". To do frequency dependant compression in the analog domain without
adding lots of distortion would be prohibitively expensive.

It may sound great (I haven't auditioned either MD or DCC), but it has no 
reason to exist when the techology to record the uncompressed bitstream  at
roughly the same price (i.e. DAT) has been around for a while.

The only good thing to come out of this mess is the MD's use of a of buffer to
store about 3 seconds of music as a way of coping with skips etc. An idea that
is mind bogglingly simple compared to the mechanical schemes used in car CD
players. It is starting to appear in portable CD players.

gary

re:   <<< Note 77.104 by ROCK::FROMM "It's hard to care about a don't care." >>>

>>I'm waiting for a 5.25" disk form factor so no reduction is necessary.
>
>i don't think it's a question of whether or not it was necessary; i think the
>recording industry thinks it is desirable

It's certainly desirable (and necessary) if you are trying to store 74 minutes
of digital audio on a 2.5" disk.  But if you don't need compression/reduction
(as would be the case with a 5.25" disk) why use it?  It's just added cost for
the product, and extra processing for the music.

But I think I see what you're getting at, Rich.  The record companies want to
deliberately induce loss in the medium to discourage piracy.  Kinda lame if you
ask me, but a sign of the times nevertheless.

As far as recordable CD, sure it's here, but I have better things to spend $4K
on.  $750 (for a recordable MD) is a lot more reasonable, but not too appealing
to me given the sonic characteristics.  Maybe if it got *real* cheap (like
$400) and blanks were priced below $10 I'd consider it.

BTW, thanks for the corrections on the technical stuff.  I didn't realize the
music gets digitized before being "reduced".

I didn't know there was more than one unit on the market.  I just happened to
see a Sanyo unit (playback only) at Service Merchandise (!) for $499 (the list
price!).  Sony must have licensed the technology (or built them in a Sanyo
box).

adam

Both MD and DCC have been heavily licensed out by their creators. My guess is
that you'll see them all priced roughly the same for a while until someone
'breaks ranks' (i.e. the next time ZikZak Corp has a cash flow problem).

gary

re:          <<< Note 77.106 by ONE900::HUGHES "Samurai Couch Potato" >>>

>Since when is 'data reduction' not compression?

In retrospect, my discussion of the differences in these definitions is
probably in error since I thought the data reduction occurred in the analog
domain.  To me, compression is taking a digital bitstream, running it through a
"black box", and getting out a new, smaller bit stream, which. when run through
the de-compression, or inverse "black box", gives you the same original bit
stream *every time*.  Such methods are used for storing large files on computer
disk, for instance.  I see this as fundamentally different from "reduction" as
performed by DCC and MD.  In DCC/MD's case, you are taking a digital bit stream
representing full bandwidth audio (as recorded on CD and DAT), and running it
through a "black box", getting out a new, "reduced" bit stream which is stored
on the disk.  When that is run through the inverse, or "inflation" (as Jeff
calls it) "black box", you get the "inflated" bit stream which is quite
obviously *nothing* like the original audio in terms of the information
contained in the bit stream.  This is a big difference to me.

What I don't understand is, what is the format of the "reduced" bit stream?  Is
it just another set of 16-bit samples at the 44.1 Khz sampling rate?  Probably
not , since you haven't saved any space.  Is there an implicit compression
algorithm used?  Just taking out those components of the audio that are
"unimportant" does not leave you with less bits, just different bits.  You
still need 16-bit samples at the sampling rate even if they're all 0's.  I must
be missing something here.

>anyway". To do frequency dependant compression in the analog domain without
>adding lots of distortion would be prohibitively expensive.

I didn't know that.  I do agree that signal processing in the digital domain is
usually easier and cheaper.  It just keeps math weenies in business. :-)

>It may sound great (I haven't auditioned either MD or DCC), but it has no 
>reason to exist when the techology to record the uncompressed bitstream  at
>roughly the same price (i.e. DAT) has been around for a while.

I guess the 2 big selling points of MD are re-recordability (up to a million
times, or, essentially, forever), and random-access.  Size isn't an issue
because portable DAT's are about the same size as a MD player.  The only
selling point of DCC is the ability to play standard cassettes on the same
machine.

adam

>Maybe if it got *real* cheap (like
>$400) and blanks were priced below $10 I'd consider it.

jeff, how much was Lechemere selling the Sony DAT's on clearance?  i think
it was $450

and once used data grade DAT tapes are roughly the same price/minute as
Maxell MX-S from Terrapin, i believe

- rich

>What I don't understand is, what is the format of the "reduced" bit stream?  Is
>it just another set of 16-bit samples at the 44.1 Khz sampling rate?

no, it's something different that's compressed, not compatable with any
standard digital audio format

- rich

re: costs of MD, DCC, DAT, etc.

To my knowledge, the cheapest DAT deck every sold new is/was the Sony
DTC-670 for ~$385 at the Lechmere Clearance Center in NH.  DAT is cheaper
than MD or DCC by a significant margin, both in terms of price per deck
(~$750 for MD & DCC and ~$500 for DAT) and in terms of price per minute of
medium (~25�/min for MD and DCC, and ~5�/min for DAT).  

- jeff

PS -- Here's an interesting article that was recently posted to
DAT-Heads...

--------------------
From: "John F. Whitehead" <[email protected]>
Subject: the future of DCC :-)
Date: Tue, 31 Aug 93 12:28:24 -0700

In Mix's September 1993 issue there is an article reporting on June's
Replitech (the duplication and replication industry's big conference).
It says that at the event there was

"a general lack of enthusiasm about either of the new audio formats [DCC
and MD] now on the market.  The jury is still out on MiniDisc, which was
generally seen as attractive but unlikely to be a major force in the music
market for the time being.  DCC, meanwhile, is widely viewed as a goner
already. 

"Philips was doing its best to keep the DCC ball rolling.  The company
held a press conference to announce several developments that could have
been significant had they come against a backdrop of promising consumer
response."

Elsewhere in the issue a point is also made that CD-ROM and even CD audio
are probably temporary formats that will not be needed once people have
high-bandwidth digital transmission into their homes. 

 ____________________________________________________________________________
|    John      [email protected]                 Audio Research Intern |
|  Whitehead   [email protected]              Human Interface Technology Lab |
|____________________________________________________________________________|

    re reduction et al
    
    Ok, what you are describing is lossy compression vs. lossless
    compression. Maybe you should trademark 'data reduction' and sell the
    name to Sony :-) They carefully avoid mention of compression in 'Sony
    Style' (now THERE is an exercise in data inflation).
    
    gary

    RE:  Digital Sound Processing
    
    Does anybody know about using software or hardware to filter out 
    unwanted sounds on a digitally recorded concert (MD or DAT)?  If I
    were to switch to Digital, could I use some sort of digital sound 
    processing software during the recording of my analog collection 
    onto a digital medium to eliminate tape hiss, etc.?  How about the 
    cost of doing such?
    
    Thanks for any advice,
    
    Steve
    

    There is such a process in use commercially, called 'NoNoise'. It was
    used to make the Europe 72 CDs. Systematic problems, such as AC hum,
    are removed by programmable filters. Other random defects are treated
    with manual editing, still in the digital domain of course.
    
    The process is/was quite expensive. It was running on VAXes, but I
    don't know what A/D and D/A gear was used.
    
    It seems to me that a 486 with one or two good sound cards would be
    able to do this. Some of the better cards have programmable DSP
    engines. Disk storage would be the most expensive part, you'd need lots
    and it would need to be reasonably fast; a 16 bit bus mastering SCSI
    adapter would be a must.
    
    You'd probably want an O/S that can walk and chew gum at the same time
    (ob. dig at windoze :-) )
    
    It is quite possible that someone has already done this as a product.
    
    gary

    Gary,
    
    Thanks for the info.  My investigation continues until I inevitably
    realize I can't afford it.
    
    Steve

> My investigation continues until I inevitably realize I can't afford it.

NoNoise is apparently the state of the art, and I bet they charge big bux
too...  The MIT Media Lab does a *lot* of DSP work.  They might have slightly
more budget-minded solutions vs. NoNoise...  I can point you to a friend of
mine -- send me mail if you're intersted.

...but nothing beats Josh Belkin for low-cost DNR hiss reduction!  :-)

- jeff

    The MIT Comp Sci dept is also doing some interesting stuff with
    realtime processing of audio and video for multimedia applications (and
    they don't have a crew of corporate underwriters like the Media Lab). A
    recent demo I saw was doing neat stuff with a pair of AXP3000s and
    their homebrew ATM switch. They put the audio and video D/A directly on
    the switch so they only need build an ATM card for the turbochannel.
    Watching events of the window lag the real world by .5 second or so
    really illustrates interrupt latency, but I digress...
    
    While this stuff is cheap from the commercial perspective, it is beyond
    most small studio or hobbyist budgets.
    
    There are a couple of electronic musician type magazines you can find
    in places like Barnes & Nobles or OOTTA. That might a good place to
    start. There have to be people tinkering with this stuff on home PC
    budgets somewhere.
    
    gary

    I'm looking for some opinions on a portable recording setup, and
    I figure the folks in here have no shortage of opinions... :) :) :)
    
    Here's the deal...  Beth, my better half, plays flute in various
    amateur groups (quartets, quintets, etc) and would like to be able
    to record her rehearsals and concerts.  I'm looking for recommendations
    for both a portable deck (preferable DAT, but I'll entertain analog
    suggestions) and a set of microphones.  I have no idea where to even
    start with this... suggestions? recommendations?
    
    	-td
    

Portable DAT decks - the only one thats less than $1K is the Sony D7, and its
successor, the D8.  Not the most reliable deck around, some people have lots
of problems, some are lucky and are OK by them.

Mikes - only thing thats decent for less than $500 or so are the 
Core Sound Binaurals, by Len Moskowitz.  Can be used in the spaced-omni
configuration - just clamp them onto a bar about 2' apart, rather than in
your ears.  Cost about $300, and have very good sound!

Josh

    
    Maybe I've been out of the loop too long...but did you know that
    several CD writers are now available for less than $1,000? I mean, you
    can't carry them into a concert to record, but can you imagine putting
    all of your DAT's onto CD? No more wear! Make CD's for your friends
    instead of analog tapes! wow...
    

    Well, I have a friend who's supposedly putting some Rundgren
    tapes on CD for me.  He works at a radio station and intends
    to borrow their CD recorder.

    The problem is the cost of the blank CD's, he estimates 
    $12.50 per disc.  Does that sound about right?  

    The other problem is the recorder he is planning to borrow
    needs to be repaired.  So I'm waiting.... waiting...  but
    I should eventually be the envy of the other kids on the block.

    Tom

> The problem is the cost of the blank CD's, he estimates $12.50 per disc.
> Does that sound about right?  

I've seen 'em offered for as low as $7 in quants of 20.

Burners are indeed now in the $1000 range.  

So ... lets get a bunch of DECheads to chip in $20 each plus $10 per
disk+shipping, and we can start putting all these DAT collections to some good
use!

Either this month's, or last month's, issue of Stereo Review review a Pioneer
CDrom writer/reader.  This is $2K machine that looks like a DAT tape deck.
Its an audio device, with analog and digital (optical, i think) in/out.
IT ONLY CAN USE THE 63 (or whatever exact # that is) MINUTE CDROMS!
Not the 74 min. CDROMS that PC CDROM burners can accept.

Josh

	having all the dat sutff on cdrom would sure make dubbing a
	best-of tape easier.

    
    Two of the 4 CD burners I saw would take 74-min CD's. The others didn't
    specify. The brands were HP, Sony, Pinnacle and JVC. It's interesting -
    in surfing the web, I saw that prices in 94 were all in the 2K range,
    in June of 95 they had dropped to 1400, and nov-dec 95 showed 3 at less
    than $1000.
    
    You also need a 1.2 gig hard drive to store the bits before you burn
    'em - it burns much faster than you can read off a DAT. You also need
    some software to go from 48KHZ to 44.1KHZ, but that's not much of a
    problem - it's out there. (Of course, if your DAT deck can record at
    44.1 - do it in the future!)
    
    I also saw multiple sources for blank CD's in the $8 range. Considering
    that if you get 250 CD's professionally burned they'll do it for $3
    per, you gotta assume that those prices will plummet as soon as the
    writers take off.
    

We burn our own Cds for my project-- assetworks.
our burner, an old one (1990!) kicked the bucket and
we're gonna get a new one... i'll have to make sure
it can do audio stuff!
so, ah jeff, when are you heading for your sail aroudn the world?
didya need someone to mind your dat tape collection? :-) :-) :-0

> we're gonna get a new one... i'll have to make sure it can do audio stuff!

I'm pretty sure most can do it.... but then again if it comes from DECital,
check first!  ;-)

> so, ah jeff, when are you heading for your sail aroudn the world?  

Tomorrow is my last day here -- catchin up on notes between fillin boxes of my
stuff in my office.  

My "Cirrus" mobile came down, but the pink alligator is still hangin' (for
now)...


> didya need someone to mind your dat tape collection?

Already spoken for.  Sorry mon!


- jeff