Conference cookie::notes$archive:cd_v1

I got a Sony CDP-30 about a year ago (their bottom of the
line model).  While this model has been discontinued, its
successor the CDP-35 is in the same price range: $250-$300.
I listened to a whole bunch of players, and discovered that
through my existing medium priced equipment [JVC RX44
reciever, AR48 speakers] just about any disk player sounds
just wonderful.  I wasn't interested in features, so
therefore, what I was looking for was reliability and speed
in accessing tracks to albums.  Now because such
measurements can be made objectively, I consulted Consumer
Reports.  [I don't recomend using CR for subjective
measurements like speaker sound etc... Your best off doing
that yourself...  They are in the business of selling
magazines, and in the past have been notibly wrong about
audio components.]  The Sony disc machines both tracked the
fastest and were rated most reliable.  I've heard rumors
that the Sony spec is that the machine should be able to
track while being dropped onto a concrete floor from one
meter.  I've had no trouble with mine, though it does skip
when shaken moderately vigourously (an accident).

I've also heard good things about Technique's bottom of the
line model, as well as their portable toy.

    I also have the Sony CDP-30 and enjoy it very much.  I have owned it
    for almost a year now and have had no difficulties with it.  It doesn't
    have alot of the features mentioned in some of the other notes
    (randomizing tracks, pitch control, etc.), but I haven't missed them. 
    As far as I'm concerned, the start, stop, pause, index, and track
    buttons are sufficient.

    I have owned a Technics player (SLP-8), one of the older models,
    and I can tell you from painful experience that it is one of the
    worst sounding units on the market .  This was not a fluke, a friend
    owned the same model and it was identical .  The push-buttons would
    not reliably work, sometimes requiring several pushes to activate
    a function .  Again, this was on both machines !
    
    The lowest price I have seen for a CD player is the Magnavox 2041
    at around $179 (U.S.) .  If you use this player as is, it will sound
    competitive with all other low end players .  If you replace two
    capacitors (DC blocking caps) you can get close to the sound of
    the Nakamichi OMS5 and OMS7 (not the new series II units though).
    
    Reliablity of the Magnavoxen has been spotty, but the price is very
    low .  They come with a full 1 year warranty from Magnavox .
    
    Best wishes in your search,
    Jon

RE: .-1

I have a Technics SLP-1 and a Carver CD Player.  The SLP-1 sounds about the same
as the Carver which sounds great.  The SLP-1 does a much better job of error
correction on damaged CDs than the Carver.  It will play things that the Carver
won't track and has easier to use random access and programming and a better
time and track display than the Carver.  You may ask why I bought the Carver 
which lists at over twice the Technics.  Sometimes I ask the same question.  
Don't judge all Technics on one model.  The SLP-1 gives you a lot for your 
money.

    I have a Technics SLP300.  I have been happy with it.  The wireless
    remote has plenty of functions on it too.  I paid $280 mail order
    for it.  This was back in Feb.

    My Technics SLP-1 has played flawless since day 1 with the exception
    of 1 error...found out it was a small piece of styrofoam from the
    packaging that got on my first cd...blew it off and wahlah!
    
    _stew-

    My SLP-8 has performed flawlessly in daily use since December 1983, and
    I have been very happy with it.  It has (rarely) exhibited deafness to
    the front panel buttons: you can wait 2-3 seconds, or if the drawer is
    out jiggle it a little; then it works.  I have read in this conference
    that the SLP-8 is accident prone; but mine is just fine (so far). 
    
    GAS
    

Re: .3:

I agree with the comments about the Magnavoxes; I have had a 1041 for about
6  months  and love it. The sound is great, features are OK, but reliability
is  a  bit of a problem -- I had to return one, and there is a minor problem
with  the  current  one  --  the on-off pushbutton sometimes sticks when you
depress  it  to turn the unit off. Good electronics, not necessarily good QC
or packaging.

By the way, I believe it is the 1041 that is $179, not the 2041.

    Re:  8
    
    AHAH!! 
    
    So the sticky on-off button is a generic problem.  I wondered whether
    to worry about it -- figure that if it does actually break, it's
    the kind of repair that should take a minimal amount of high-skill
    diagnosis and fault isolation.....
    
    I like my 2041 a lot.  No problems at all (knock on wood).  Sounds
    great.  Controls are straightforward, and I haven't yet missed having
    a remote control.
    
    I was reminded over the weekend how wonderful CD's (and their players)
    are when a babysitter fractured yet another stylus on the old Thorens.
    The price of a replacement stylus is appallingly close to the cost
    of a whole Magnavox 2041!
    
    Triesman's (Nashua) standard price for 2041 is $179.
    
    dq
    
    

    
    yeah, love that sticky on/off button - even on a 2051.
    
    perhaps when I (with help from you guys of course) rebuild this
    one, i'll fix that button.
    
    						.dave.

    Do you guys turn your stuff off?  Try leaving it on 24-hours or
    so an then listening.  I did this about 6 years ago with my first
    Hafler/Bryston electronics and have never shut it off since.  It
    is hard on incandescent panel lights and I wouldnt suggest it with 
    tubed gear unless you have too much money.
    
    Does anyone remember a fellow named Andy Rappaport?  He is a young
    designer who was in the business of hi-end audio electronics untill
    his wife ran off with his chief designer(another story). Anyway,
    his second line of gear (his first preamp was just OK) was really
    super stuff (all class A, etc.) and it featured a "warm" off. What
    Andy did was bond resistors to each active device in the unit and
    powered them when the unit was switched off to keep all the transistors
    warm. It sort of worked. His preamp sounded as good about 3-4 hours
    after "turned on" from "warm off" as it did 24 hours after plugging
    in cold and turning on.
    
    Walt (dont thank me, just name your first born after someone else)
    

    Re: 11.
    
    Walt,  I agree completely about leaving amplifier and tuner on all
    the time (extends to terminal in the office where the Security people
    used to complain until I got a VT240 with the phosphor-saver feature).
    
    But I understand (Digital Audio?  here?  not sure) that CD players
    are best not left on permanantly, something to do with heat dissipation
    from the laser.
    
    dq

    In response to .0, I just finished a discussion of what I bought
    last month, a Technics SP-LJ33 in 398.1 - 398.2.
    

    Re: .11, .12
    
    I dont have info on ALL Laser driven products here, but according
    to Philips, Sony and Pioneer CD and LV (as in RRD50, VDP40, VDP50)
    info, the laser must be shut down anytime a disc is not inserted.
    
    There are 2 reasons: 1) The laser must be able to servo in order
    to focus which requires a disc. To overide the lost focus point
    the laser is shut off. 2) Due to safety considerations the laser
    must not be able to be turned on when a door is opened or a disc
    is not in place.
    
    This leads me to believe that leaving a unit on would have no effect
    on laser life, unless you left a disc in all the time.
    
    Walt 

I've had absolutely no problem with my SLP-1 since I bought it
back in March of 85.  It runs pretty hot but the heat is due
to the power supply regulator ICs.

I assumed that every CD player sounds the same (that was what
all the stereo magazines said) and I bought it without 
even listening to it.  I was pretty disappointed when I first
listened to it and found my first CD to sound a lot worse 
than the album (Pat Metheny's Offramp), and my turntable is
pretty low end.  (Technic SL-1800 with ADC XLM MkIII and Grado F3+
cartridges.)

In short I find the SLP-1 mechanically quite reliable but
sonically inferior.  So I certainly hope not all players
sound the same.

May be some day I'll replace the op-amps and the capacitors on
one channel and see if there is any improvement.

/tom

    Tom,  Does the Technics CD use IC opamps in the analog section ?
    That would be pretty unusual for Technics.  I did a bunch of reworking
    on the analog section of my Technics RS-1500 open reel. I found
    the circuit design to be fairly good, and I replaced or bypassed
    or direct coupled all capacitors (about 40 in all - fortunatly small
    values) replaced a few resistors, and built a separate power supply
    for the analog section, using my own whiz-bang design.  I also
    replaced most long signal runs internally (both cables and etch)
    with hi quality siver/copper twisted quad pair.  The results were
    stunning.   Anyway, the point is, a lot of these units (IC or discrete)
    CAN be improved. It may take a bit more than 2 caps in some cases,
    but the designs have potential hidden there. 
    
    Walt

Walt,

I think so.  It uses one Burr-Brown PCM53J (I think) for D/A, and
followed by three LM833 (are they opamps?). Don't know where three
instead of two or four.  Most caps are ceramic, a few mylars, and
a few electrolytics.  I suspect the filter and sample and hold
stuffs are done in custom hybrid.  There are two blue epoxy moded
chips with Technic part numbers that appear to have opamps and 
capacitors, I suspect they are the low-pass filters.

I really should get a circuit diagram before I dare to do any mods
since there are far too many surface mount custom chips for me
fiddle around with.

Any idea of where I can get a circuit diagram?

/tom

    Re: .17
    
    I got the service manual for the RS-1500 from Panasonic/Technics
    in New Jersey. It was some time ago.   There is a service safety
    issue on CD players having to do with laser safety, so I am not
    sure if there are any restrictions on manual distribution (probably
    not).
    
    The LM833 is discussed in a couple other places in CD and Audio
    notes (mostly what is better, etc.) but it is probably being used
    as the amplification stage.  It may also be in use as active analog
    filters, or DC servoing, and so on, so the manual is probably
    worth the effort if you plan to modify.   Working with SMT isnt
    the easiest thing you'll do but as long as there is space for
    components in the box, its not unmanagable either.  
    
    Im kinda surprised the Technics is using IC opamps. It does make
    decisions regarding improvements easier for you though. Performance
    (both objective and subjective) is readily available for many
    IC opamps. Only a few discrete opamps (like the JE-990) have been
    widely published and tested. 
    
    Walt