Conference cookie::notes$archive:cd_v1

I haven't had that problem, I use the pause on RMS play and it works fine.
I will play some tonight to see if my newer one does this.

With the first D7 I bought I heard scrapping inside the unit.  By mounting
the disk differently it would subside, but the last straw was a Telarc 
disk that was being filed down by the source of the scrapping.  The source
was in the assembly in the front of the machine were the black plastic/metal
front abutted the dull black metal inside housing.  One section was a little
higher than the other.  In the new one I just laid the disk on without
tilting it and it worked fine no scrapping.

I'll play with mine some more and see if I can get it to do what you described.

Dan

    Hey, am I glad you entered this note - 

			I thought I had the D7 that ate Digital !!

    I had the exact same experience today.  I had put in a CD, pressed 
START, started pressing PLAY to get to SHUFFLE.... and was locked-in
spinning at 00.  I went through the same sequence of steps until I 
finally removed the battery and pulled it's plug (that's always worked
in the movies...)

    I have a question - are you using your D7 in work ?  And, if so, do
you have it near your monitor ?

    Reason I ask - Thinking it over on the way home I wondered about the 
following. I used the D7 quite a bit at home over the weekend and there 
was never a hint of misbehavior.  However, today at work it really acted 
up (skipping, missing tracks, everything).  It's misbehaved before at work 
also. It also seemed the worst when I was using my Rainbow color monitor 
to display colored text (as opposed to just the green gun).  

    Now, I realize that this is the stuff that serious people create
stampedes from.  Never-the-less, I'm planning a series of experiments for
tomorrow.   I'll let you know.

(Meanwhile - no "killer VDT" articles to the trade pubs just yet, OK ?)

PS - I, too, still love my D7 !!  (best-ever music-maker-to-go!!!)

                             Art

    	I seem to recall my D-7 freaking out once or twice when I went
    into one of the special modes too.  The display kept flashing zeros
    that were sort of circuilating.  However I simply hit the stop button
    and that cleared the problem.  So it may have been a technical snaffu
    but probably not the same one the rest of you have.  One other problem
    I had, which is kind of funny because it was my fault, was one time
    the player kept shutting off when I tried to play it.  Turned out
    that I placed a CD into the D-7 when there was one in there already.
    
    :^)

RE: .0,.2

	I experimented with starting the unit and pressing the play button
suffle play but didn't have the same problems that you both seem to have.
But, I have been using my player at work.  I have a VT240.  As I described
earlier, the disk was scrapping inside the housing and leaving plastic
shavings inside the housing.  But, I had the skipping problem .2 describes.
The player seemed to automatically go into search mode both fast-forward and
reverse w/o me touching it.  That was the last I played with it before I
brought it back for an exchange.  The new one I haven't brought to work, yet.

I called Sony and they said that I shouldn't hear any scrapping, have any other
D7 owners had any scrapping problems?  What did you do to resolve it?

With the second player I was getting a scrapping noise in the music this
morning.  Fixed by taking out and putting the CD back into the machine.
Has anybody had this problem?

I love the sound and portablility, too
Dan

>    I have a question - are you using your D7 in work ?  And, if so, do
>you have it near your monitor ?

    My D-7 was about 6 inches away from my VR241 (color monitor).  Hmmm...
    
>    Reason I ask - Thinking it over on the way home I wondered about the 
>following. I used the D7 quite a bit at home over the weekend and there 
>was never a hint of misbehavior.  However, today at work it really acted 
>up (skipping, missing tracks, everything).  It's misbehaved before at work 
>also. It also seemed the worst when I was using my Rainbow color monitor 
>to display colored text (as opposed to just the green gun).  

    Maybe Digital should issue a warning about using D-7s in the vicinity
    of VR241s? :-)  Well, that was the first (and so far only) time
    my D-7 has acted up.  Could the D-7 be sensitive to EMI?  Magnetic
    fields?  
    
    Well at least I'm not alone in what happened.
    
    matt

    I hope the VT240/241 meets DEC STD 103, or are we shipping doo doo?
    
    Oppps, some MEI folks might get mad, sorry :-)
    
    Jeff
    

    Unlike phono cartridges (strain gauge and ceranic excepted) and
    tape heads, the laser system on CDs should be very immune to EMI
    since the pickup principle is light conversion to electricity and
    not magnetic field induced electricity.  Further, both phono and
    tape are very weak at the sensing transducer compaired to Laser
    which further increases the effect of any EMI which might be induced
    into the front end amplification circuits.
    
    Walt

    Hmmmmm.  Very true.  But what about all the little guys inside that
    control all this stuff (transport mechanisms, display, and the like).
    
    Dave W.

    Thats the nice thing about digital circuitry. The logic 1 and 0
    levels are so far apart (usually 3 volts or more) that there is
    little chance of causing a logic reversal from induced EMI which
    would appear as +/- millivolt changes.  Also, many digital circuits
    are synched to a clock which makes the circuits ignore everything
    between regardless of level.  
    
    That pretty much leaves Gamma ray emissions striking a RAM semi
    junction and changing the state of that bit, static electric discharge
    causing both temporary and permanent fauliure  and other theories
    about the nature of random errors in digital circuits. By the way
    most low cost/high reliability digital designs have very little
    in the way of built-in error detection and correction beyond what
    is expected of the unit (ECC for CD read correction and positioner
    error correction) so a transient hardware fault may very well leave 
    the machine in never-never land untill a power on reset.

    Walt 

    Re: Magnetic Fields?
    
    Tell me you were playing Jean Michael Jarre when it happened! :-)
    
    My Sony CDP101 once wen't off into never-never land in my home
    stereo rack, I chalked it up to a static discharge as it only
    happened that one time.  If you are playing your portables near
    a video monitor I would expect more static buildup than normal,
    due to the high voltages involved (and the materials involved,
    given the vinyl coating of a CD).  Unless your CRT's are mil-spec,
    I doubt they are shielded enough to prevent this from occurring.
    However, I am by no means an expert (or even close to an expert)
    in this area, so what do I know.  Intuitively it would seem like
    there could be a correlation.
    
    Actually, taking this one step further, if there is scraping, then
    the specs must be very close, the material of the CD constantly
    rotating close to the cover may be causing some static buildup,
    whether or not there is a CRT present.  Touching the front panel
    may provide just enough grounding to cause a static discharge
    internally, and messing up the internal digital control circuitry.
    
    Take notes when it happens to indicate if it is a dryer than normal
    day...
          
    						-Dave

    RE:  vinyl coating of a CD
    
    The CD's aren't vinyl coated to my knowledge.  They are made of
    polycarbonate, which also could build up a static charge, and are not
    coated over that.  I haven't done any static testing, as I don't have a
    cat handy :^). 

    re .11: I think that the "label" side IS coated with something on some
    CDs to protect the delicate aluminized surface. The bulk of the
    material is polycarbonate, though. 

    From what I remember reading in an issue of "Plastic Engineering"
    about the making of CD's, the aluminized layer is buried under a
    layer of polycarbonate.  One of the breakthrough's in this technology
    was finding a resin that was easy to process and had outstanding
    optical properties so that the laser could pass through it to read
    the pits in the aluminum underneath.  The coating you are referring
    to may be there to act as a binder for the printing.
    
    Maybe I should bring one into our lab someday and analyze it.  Anybody
    got a disc they are not too fond of :^)?

    In the current CD production technology, the polycarbonate is injection
    molded with a flat bottom surface, and pits in the top.  The top
    is then aluminized by vapor deposition.  Then a layer of UV-curable
    monomer is spun on and cured by UV light.  The label is then
    silkscreened on (in the same UV curable monomer, but with pigment
    added).
    	
    That's why a scratch on the top surface (the side that "doesn't
    play") is more dangerous than a scratch on the bottom; the protective
    plastic is much thinner there.
    

>>    In the current CD production technology, the polycarbonate is injection
>>    molded with a flat bottom surface, and pits in the top.  The top
>>    is then aluminized by vapor deposition.  Then a layer of UV-curable
>>    monomer is spun on and cured by UV light.  

That's true at SONY, but not a PolyGram; PG uses an air-curing (believe it
or not!) varnish.

>>    The label is then
>>    silkscreened on (in the same UV curable monomer, but with pigment
>>    added).
>>

Well -- sorta. They just run those little guys thru a 3-color printing press to
get the "labels" on. No UV-curable monomer, at least at PG, just silk-screen
inks!

>>    	
>>    That's why a scratch on the top surface (the side that "doesn't
>>    play") is more dangerous than a scratch on the bottom; the protective
>>    plastic is much thinner there.
Exactly.

/don feinberg    

    I "took the plunge" on Saturday (as well as a raincheck that was
    going to expire) and bought a D7 at leechmere's.  Wonderful little
    box.
    	
    Except that when it's running with the wall plug in, it can't play
    past about the 52'nd minute of any disk I've tried (four).  None
    of these disks has any trouble in my Big Old Dusty NAD.   The D-7
    has no trouble when it's not attached to the wall (i.e. running
    on the lead-acid flat-pack is fine).  It just won't track when it's
    running from the wall transformer (attaching the battery does NOT
    help, unless you pull the wall-input 9-v line.
    	
    My hunch- this particular D7 has a rough spot in the transport that
    draws a bit too much juice to play correctly when being powered
    by that small wall-transformer.  The lead-acid pack has a far larger
    current reserve, so it has no trouble with the rough spot.
    	
    The failure mode is bizarre- first you hear little glitches, about
    every two seconds, then bigger glitches, then after about two minutes
    of steadily worsening sound, the player just gives up and turns
    itself off. Neat, huh?
    	
    Back to Leechmere's tonight.  I'm going to get my moneysworth out
    of their highly-vaunted returns policy (I already returned my first
    set of headphones for a more expensive set that actually were
    mid-to-high fi).	
    	                      
    	
    Anybody else have this problem?  It sure is annoying to have your
    Walkure garbled.  

    ? This note seems to be bringing out all of the problems
    associated with the D7.
    
    Why would anyone want to buy one ?
    
    just curious...

    I have the new one now, and it seems to work fine.  
    	
    	Why would anyone buy a D7?  Why do people buy walkmans?
    	
    1)portable, very high quality sound, which 
    	shuts out the trash noises in the office environment
    	
    2)It can be cobbled into the car stereo system (I use an adapter
        made by Spark-o-Matic, which supplies 9 volts to the d7 and
    	rebroadcasts the d7 output at 90.1 MHz FM stereo.  So, I get
    	digital audio in my car for $20 more.
    	
    3)CDs don't get eaten like tapes do.
    	
    4)It's high-tech- and therefore nifty to have.
    
    5)I don't have to transcribe my home CD's to tape to listen to
    	them in the office, on the road, etc.  One media.
    	
    6)All my friends have one, anyway.....
     

    How about Technics new portable.
    
    I have read very good review on it, I don't remember the model
    
    number.

>    2)It can be cobbled into the car stereo system (I use an adapter
>        made by Spark-o-Matic, which supplies 9 volts to the d7 and
>    	rebroadcasts the d7 output at 90.1 MHz FM stereo.  So, I get
>    	digital audio in my car for $20 more.


	Would you care to supply a bit more info on this?  I think
I would be very nterested in buying one of these!!

Thanks 

Oscar CEDSWS::NEWKERK
    	

    I bought the adapter at K-mart, near Albany, NY.
    	
    Do you want one?  I go near albany on a regular basis.  I'm in
    HLO (hudson).
    	
    (the sound is good- but what do you want for $20?  I haven't put
    the adapter on any sort of distortion analyzer, it just sounds as
    good as GBH noise-wise)
    	
    The adapter wants 12 volts in, and you unplug the antenna lead going
    into the car FM.  The adapter plugs into the radio, and you stick
    the old FM antenna line into a jack on the back of the adapter so
    that you can still get the other stations.
    	
    Adapter physical size- about 1 inch by three by two.  Includes all
    necessary cabling (including a power plug that matches a D5/D7 and
    one for the earphone jack.  Both cables are double-ended.
    	
    Anything more you want to know?

    I saw this adapter or one like it in a store called something
    like A-to-Z (should we sue?) in the Chestnut Hill Mall in Newton
    recently.

    We bought one at a local auto supply store around Christmas time
    and think that it's a reasonable device for the price.  It's reasonably
    painless to install as long as you don't mind poking around in the
    fuse box.
    
    Gary

    The K-mart up near Leominster, Mass. now has two of them in stock, both
    of which have unsealed cases but may be complete nonetheless.
    	
    Cost: 22.97 plus tax.  (I had to pick up one for my girlfriend.)
    

K-Mart in Salem NH had about 11 in stock for $22.97 with NO tax.  They had 12 
until I got there.

    I'm about to pick up a D-7, and am curious if people have had trouble
    with them in their cars.  I know this came up in a prior note
    someplace, but given the current discussion....
    
    I played with one of the d7's at a store, and it seemed quite sensitive
    to shocks (skipping, etc.)  How have they fared in your cars?  And
    what type of car are they in??

    No problems with skipping as long as it's level (the car is a Subaru
    XT Turbo 4WD with the active suspension - which is kind of stiff)
    	
    If I put the D7 flat on the rigid console, no skips even over potholes.
    If I put it on the seat (which tilts back some) then there are quite
    a few skips, even though there is much less vibration.  I think
    that as long as you keep your deck LEVEL (or with the main vibration
    axis of the car parallel to the disk spindle) you should do fine.
    	
    Be careful changing CD's on the road.  Those jewel boxes can be
    tricky one-handed.